Sector Color
C9486E

Increase Green Roofs & Urban Greenspace

Submitted by Drawdown Admin on
Sector
Buildings & Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency
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Peatland
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Description for Social and Search
Increase Green Roofs & Urban Greenspace
Solution in Action
Speed of Action
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Caveats
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Risks
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Consensus
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Trade-offs
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Action Word
Increase
Solution Title
Green Roofs & Urban Greenspace
Classification
Highly Recommended
Lawmakers and Policymakers
Practitioners
Business Leaders
Nonprofit Leaders
Investors
Philanthropists and International Aid Agencies
Thought Leaders
Technologists and Researchers
Communities, Households, and Individuals
Updated Date

Boost Appliance & Equipment Efficiency

Submitted by Drawdown Admin on
Sector
Buildings & Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency
Image
Washing machines on conveyer belts in a factory
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Summary

Boosting the efficiency of appliances and equipment cuts GHG emissions by reducing the amount of electricity used to operate these devices. Efficiency improvements also lead to reduced peak demand, less strain on the electric grid, and potential utility savings for homeowners due to reduced electricity use. Despite this potential, the increase in the total number of households and average ownership of appliances, especially in low- and middle-income countries, has offset the impact of efficiency gains and resulted in increased electricity consumption from devices globally. We conclude that Boost Appliance & Equipment Efficiency is “Worthwhile” because it functionally reduces the energy consumed by these devices, but significant leaps in efficiency and shifts in user behavior are needed to realize its full potential as a climate solution.

Description for Social and Search
Boosting the efficiency of appliances and equipment cuts GHG emissions by reducing the amount of electricity used to operate these devices.
Overview

What is our assessment?

Based on our analysis, boosting appliance and equipment efficiency is a promising strategy for reducing GHG emissions, but significant leaps in efficiency and shifts in user behavior are needed to counteract the rebound effect and realize its impact. This potential climate solution is “Worthwhile.”

Plausible Could it work? Yes
Ready Is it ready? Yes
Evidence Are there data to evaluate it? Yes
Effective Does it consistently work? Yes
Impact Is it big enough to matter? No
Risk Is it risky or harmful? No
Cost Is it cheap? Yes

What is it?

Appliance and equipment efficiency typically refers to larger devices in residential buildings that run on electricity, such as refrigerators, freezers, washing machines, dishwashers, dryers, and televisions. Energy-efficient appliances or equipment consume less electricity when operated than do inefficient devices. Therefore, boosting appliance efficiency reduces the CO₂, methane, and nitrous oxide emissions from electricity generation. As of 2022, the energy consumed by household appliances globally was more than twice the total energy used to cool both residential and nonresidential buildings, and about half the energy used for heating. To drive higher efficiency for these devices, various countries have established regional energy efficiency standards, rating systems, and labeling programs. Currently, homeowners can readily access a variety of options on the appliance market, and less efficient devices can easily be replaced. However, income levels, especially in low- and middle-income countries, may affect people’s actual ability to purchase certain appliances, although these devices are increasingly becoming cheaper.

Does it work?

Improving the efficiency of appliances and equipment functionally reduces the energy required to run these devices. Various field studies have demonstrated the effect of efficiency gains on lowering electricity consumption. However, the rise in appliance ownership per household and the growing total number of households have offset the collective climate impact expected from efficiency improvements. Globally, the number of households grew from about 1.5 billion in 2000 to 2.2 billion in 2021. Considering the concurrent increase in the global average units owned per household, the number of appliances in use has essentially doubled over the same period. For example, we estimate that over two decades, the number of televisions owned grew from about 1.4 to 2.8 billion units, refrigerators grew from 0.9 to 1.7 billion units, and washing machines grew from about 0.6 to 1.1 billion units. This growth resulted in rising electricity consumption by appliances annually, from 2,880 TWh in 2000 to 5,734 TWh in 2022, which translates to a 99% global increase, largely driven by the Asia-Pacific region.

Why are we excited?

Boosting appliance and equipment efficiency allows homeowners to realize operational cost savings as a result of lower electricity consumption and utility bills. Compared with less efficient devices, using appliances with higher efficiency ratings functionally reduces peak electricity demand, alleviating strain on the electric grid. The advent of smart devices and the Internet of Things (IoT) also helps to automate the operation of these appliances, optimizing their runtime while minimizing the energy consumed. Initial purchasing costs are also declining, making efficient appliances more accessible and affordable. 

Access to high-efficiency appliances also yields additional benefits. For example, access to energy-efficient refrigerators and freezers means that food waste can be minimized with less energy, leading to better food security. Similarly, multimedia equipment, such as television sets, offers access to critical information. Further cuts in GHG emissions are also possible as the electric grid transitions to renewable energy sources.

Why are we concerned?

Despite the potential benefits, the efficiency improvements in household appliances and equipment have not effectively translated into a positive climate impact. This is largely due to the significant rebound effect, or the increase in appliances owned by households as these devices become cheaper and more efficient. Considering the role of appliances in providing a greater quality of life, limiting the increase in appliance purchases is dismissible. The markets for appliances and equipment in many countries also still consist of pre-owned devices, which are less efficient. Some countries, such as Ghana, have established legislation to prevent the importation of pre-owned devices. This approach ensures that the appliances bought by homeowners will run on the newest, most efficient technologies. Recent findings from regions with stringent energy rating systems also suggest that regulations and programs can lead to a 50% cut in the electricity consumed by appliances. Global initiatives, such as the United for Efficiency (U4E) partnership, which seeks to shift appliance markets in low- and middle-income countries into high-efficiency devices, are increasingly needed for the potential energy savings to be realized as a climate solution.

Solution in Action

CLASP. (2023). Net zero heroes: Scaling efficient appliances for climate change mitigation, adaptation & resilience. CLASP. Link to source: https://www.clasp.ngo/wp-content/uploads/2024/01/CLASP-COP28-FullReport-V8-012424.pdf

Darshan, A., Girdhar, N., Bhojwani, R., Rastogi, K., Angalaeswari, S., Natrayan, L., & Paramasivam, P. (2022). Energy audit of a residential building to reduce energy cost and carbon footprint for sustainable development with renewable energy sources. Advances in Civil Engineering, 2022(1), 4400874. Link to source: https://doi.org/10.1155/2022/4400874

de Ayala, A., Foudi, S., Solà, M. d. M., López-Bernabé, E., & Galarraga, I. (2020). Consumers’ preferences regarding energy efficiency: A qualitative analysis based on the household and services sectors in Spain. Energy Efficiency, 14(1), 3. Link to source: https://doi.org/10.1007/s12053-020-09921-0

de Ayala, A., & Solà, M. d. M. (2022). Assessing the EU energy efficiency label for appliances: Issues, potential improvements and challenges. Energies, 15(12), 4272. Link to source: https://doi.org/10.3390/en15124272

IEA. (2022, 22 September 2022). Worldwide average household ownership of appliances and number of households in the net zero scenario, 2000–2030. Retrieved April 20, 2025, from Link to source: https://www.iea.org/data-and-statistics/charts/worldwide-average-household-ownership-of-appliances-and-number-of-households-in-the-net-zero-scenario-2000-2030

IEA. (2023). Space cooling: Net zero emissions guide. IEA. Link to source: https://www.iea.org/reports/space-cooling-2

IEA/4E TCP. (2021). Achievements of energy efficiency appliance and equipment standards and labeling programmes. IEA. Link to source: https://www.iea.org/reports/achievements-of-energy-efficiency-appliance-and-equipment-standards-and-labelling-programmes

Lane, K., & Camarasa, C. (2023, 11 July 2023). Appliances and equipment. IEA. Retrieved May 13, 2025, from Link to source: https://www.iea.org/energy-system/buildings/appliances-and-equipment

Stasiuk, K., & Maison, D. (2022). The influence of new and old energy labels on consumer judgements and decisions about household appliances. Energies, 15(4), 1260. Link to source: https://doi.org/10.3390/en15041260

United for Efficiency (U4E). (2025). About the partnership. United Nations Environment Program (UNEP). Retrieved May 15, 2025, from Link to source: https://united4efficiency.org/about-the-partnership/ 

Credits

Lead Fellow

  • Henry Igugu, Ph.D.

Contributors

  • Zoltan Nagy, Ph.D.
  • Amanda D. Smith, Ph.D.

Internal Reviewer

  • Christina Swanson, Ph.D.
Speed of Action
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Caveats
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Additional Benefits
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Risks
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Consensus
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Trade-offs
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Action Word
Boost
Solution Title
Appliance & Equipment Efficiency
Classification
Worthwhile
Updated Date

Use Low-Flow Fixtures

Submitted by Drawdown Admin on
Sector
Buildings & Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency
Image
Water streaming from shower head
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Summary

Low-flow fixtures reduce GHG emissions by reducing the volume of hot water used and therefore reducing the emissions from the energy used to heat that water. Reduced water usage also leads to fewer emissions from treating and pumping water for domestic use. Low-flow fixtures are low-cost and simple to install. They generate utility bill savings for households and support sustainable water resource management. Modern quality low-flow fixtures have resolved many of the performance issues of earlier versions. Even with significant adoption, however, the total emissions reduction potential for low-flow fixtures is relatively small. We conclude that, despite its modest emissions impact, Use Low Flow Fixtures is “Worthwhile” due to its relative ease, low cost, and additional benefits.

Description for Social and Search
Low-flow fixtures reduce GHG emissions by reducing the volume of hot water that is used and therefore reducing the emissions from the energy used to heat that water.
Overview

What is our assessment?

Based on our analysis, using low-flow fixtures is a cost-effective strategy for reducing water consumption, but has only a modest impact on GHG emissions. Therefore, this climate solution is “Worthwhile.”

Plausible Could it work? Yes
Ready Is it ready? Yes
Evidence Are there data to evaluate it? Yes
Effective Does it consistently work? Yes
Impact Is it big enough to matter? No
Risk Is it risky or harmful? No
Cost Is it cheap? Yes

What is it?

Low-flow fixtures lessen the total consumption of water by reducing flow rates through a household faucet or shower. Less hot water use means fewer emissions from the energy source used to heat the water, and it also means fewer emissions from pumping and treating tap water. Heating water for showers, sinks, and other domestic appliances is often the second largest source of emissions from buildings after space heating. Modern low-flow showerheads can produce comparable pressure and coverage to traditional showerheads through aeration and/or laminar flow. Aerators for faucets and low-flow showerheads are relatively low-cost investments that users can install themselves.

Does it work?

Low-flow fixtures reduce emissions from heating, delivering, and treating water by reducing hot water consumption. There is ample evidence for water savings with low-flow fixtures, as well as for the linkage between quantity and source of energy used for water heating and GHG emissions. Additionally, there is substantial research on the emissions from treating and pumping water, which can be reduced through water conservation. Low-flow fixtures are readily available, and performance labels are available to help consumers select quality products.

Why are we excited?

Low-flow fixtures conserve water, which reduces emissions, reduces energy demand, saves consumers money, and helps with sustainable water resource management. Households that adopt low-flow fixtures can enjoy significant utility bill savings because these fixtures reduce both water consumption and the energy used to heat water in the home. Faucet aerators also produce a smoother water stream with less splashing, and along with low-flow showerheads, are low-cost and simple to install. Household water conservation practices, such as low-flow fixtures, can help with regional sustainable water resource management and defer infrastructure expansion projects. This is particularly important in areas where water resources are increasingly strained due to climate change, growing populations, and other factors. In some regions, community water conservation efforts have had measurable impacts on water treatment costs, resulting in lower water rates for consumers.  

Why are we concerned?

Even with widespread adoption, low-flow fixtures would have a relatively small impact on GHG emissions. Moreover, the low cost and ease of replacement mean that low-flow fixtures can be easily reverted to less efficient fixtures, eliminating the emissions impact and other benefits. Lastly, although modern quality low-flow showerheads are comparable to traditional fixtures, the poor quality of early low-flow showerheads may have contributed to decreasing levels of adoption in some areas.

Solution in Action

Alliance for water efficiency. (2017). Conservation keeps rates low in Tucson, Arizona. Link to source: https://allianceforwaterefficiency.org/wp-content/uploads/2017/06/AWE_Tucson_ConsRates_FactSheet_final.pdf

Dieu-Hang, T., Grafton, R. Q., Martínez-Espiñeira, R., & Garcia-Valiñas, M. (2017). Household adoption of energy and water-efficient appliances: An analysis of attitudes, labelling and complementary green behaviours in selected OECD countries. Journal of Environmental Management, 197, 140–150. Link to source: https://doi.org/10.1016/j.jenvman.2017.03.070

Environmental protection agency. (2022). WaterSense performance overview: Showerheads. Link to source: https://www.epa.gov/system/files/documents/2022-05/ws-products-perfomance-showerheads.pdf

Kenway, S. J., Pamminger, F., Yan, G., Hall, R., Lam, K. L., Skinner, R., Olsson, G., Satur, P., & Allan, J. (2023). Opportunities and challenges of tackling Scope 3 “Indirect” emissions from residential hot water. Water Research X, 21, 100192. Link to source: https://doi.org/10.1016/j.wroa.2023.100192

Maas, A., Puri, R., & Goemans, C. (2024). A review of residential water conservation policies and attempts to measure their effectiveness. PLOS Water, 3(8), e0000278. Link to source: https://doi.org/10.1371/journal.pwat.0000278

Paraschiv, S., Paraschiv, L. S., & Serban, A. (2023). An overview of energy intensity of drinking water production and wastewater treatment. Energy Reports, 9, 118–123. Link to source: https://doi.org/10.1016/j.egyr.2023.08.074

Pomianowski, M. Z., Johra, H., Marszal-Pomianowska, A., & Zhang, C. (2020). Sustainable and energy-efficient domestic hot water systems: A review. Renewable and Sustainable Energy Reviews, 128, 109900. Link to source: https://doi.org/10.1016/j.rser.2020.109900

Tomberg, L. (2024). Resource conservation through improved efficiency, behavioral change, or both: Willingness to pay for (smart) efficient shower heads. Resources, Conservation and Recycling, 203, 107387. Link to source: https://doi.org/10.1016/j.resconrec.2023.107387

Yateh, M., Li, F., Tang, Y., Li, C., & Xu, B. (2024). Energy consumption and carbon emissions management in drinking water treatment plants: A systematic review. Journal of Cleaner Production, 437, 140688. Link to source: https://doi.org/10.1016/j.jclepro.2024.140688

Zhou, Y., Essayeh, C., Darby, S., & Morstyn, T. (2024). Evaluating the social benefits and network costs of heat pumps as an energy crisis intervention. iScience, 27(2), Article 2. Link to source: https://doi.org/10.1016/j.isci.2024.108854 

Credits

Lead Fellow

  • Heather McDiarmid, Ph.D.

Internal Reviewer

  • Christina Swanson, Ph.D.
Speed of Action
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Caveats
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Additional Benefits
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Risks
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Consensus
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Trade-offs
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Action Word
Use
Solution Title
Low-Flow Fixtures
Classification
Worthwhile
Updated Date

Use Heat Pumps

Submitted by Drawdown Admin on
Sector
Buildings & Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency Shift Energy Sources
Image
Heat pumps
Coming Soon
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Summary

Heat pumps use electricity to efficiently move heat from one place to another. This solution focuses on the replacement of fossil fuel–based heating systems with electric heat pumps. Heat pumps are remarkably efficient because they collect heat from the outside air, ground, or water using a refrigerant and use a pump to move the heat into buildings to keep them warm in colder months. Heat pumps typically replace heating systems such as boilers, furnaces, and electric resistance heaters. Many will also replace air conditioners, because the same pump can move heat out of a building in warmer months. 

Heat stress
Income & work,Health
Description for Social and Search
Heat pumps are a Highly Recommended climate solution. They replace heating systems that burn fossil fuels; many can also provide cooling in hotter months.
Overview

Heat pumps use a refrigerant cycle to move heat. When the liquid refrigerant enters a low pressure environment, it absorbs heat from the surrounding air (air-source heat pumps), water, or ground (ground-source heat pumps) as it evaporates. When the refrigerant vapor is compressed, it condenses back into a liquid, releasing the stored heat into the building. By passing the refrigerant through this cycle, a heat pump can move heat from outside to inside a building. 

Absorbing heat from the outside gets more difficult as temperatures drop. However, modern cold-climate heat pumps are designed to work effectively at temperatures approaching –30 °C (–22 °F) (Gibb et al., 2023). The freezer in your home uses the same technology, moving heat out of the cold box into the warm room to keep your food frozen. In most systems, the refrigerant cycle in a heat pump can be reversed in warmer months, moving heat out of a building to ensure its occupants are comfortable year-round. 

Heat pumps are very efficient at using electricity for heating. This is because they move heat rather than generating heat (e.g., by combustion). For example, a heat pump may have a seasonal coefficient of performance (SCOP) of 3, meaning it can move an average of three units of heat energy for every unit of electrical energy that it consumes. Conventional combustion and electric resistance heaters cannot produce more than one unit of heat energy for every unit of fuel energy or electrical energy provided. 

Heat pump systems may be all-electric or hybrid, where a secondary fossil fuel-based heating system takes over in colder weather. 

A heat pump’s potential to reduce GHG emissions depends on the heating source it replaces and the emissions intensity of the electricity used to run it. When heat pumps replace fossil fuel-based heating, they displace the GHG emissions – primarily CO₂ – generated when the fuel is burned. When replacing electric resistance heaters, heat pumps reduce the GHG emissions from the electricity to power the system because heat pumps are much more energy efficient. As electrical grids decarbonize, the GHG emissions from operating heat pumps will decrease. 

All-electric heat pumps provide the most climate benefit because they can be powered with clean energy, but hybrid heat pumps also play an important emissions-reduction role. Hybrids consist of a smaller electric heat pump system that switches to fuel-based heating systems in colder weather. They may be attractive due to lower up-front costs and because they have lower peak power demand on cold days, but hybrids also have a smaller emissions impact. Our cost and emissions analyses assumed all-electric air-source heat pumps, while the data used in the adoption analysis included all types of heat pumps with the expectation that all-electric versions will dominate in the longer term. 

In this analysis, we calculated effectiveness and cost outcomes from specific countries with high heat-pump adoption (European countries, Canada, the United States, Japan, and China) to avoid comparing research studies that use different assumptions. The analysis used global assumptions for heating system efficiency: 90% for fueled systems (International Gas Union, 2019), 100% for electric resistance (U.S. Department of Energy [U.S. DOE], n.d.), and SCOP of 3 for heat pumps (Crownhart, 2023). We also assumed all existing fueled systems use natural gas, which is currently the dominant fossil fuel used for space heating globally (International Energy Agency [IEA], 2023b). The analysis did not include emissions or costs from cooling but did assume the heat pump is replacing both a heating and cooling system. 

The cost and effectiveness analyses focused on residential heating systems due to availability of data and also because large variations in the cost and size of commercial systems make it more challenging to estimate their global impacts. Commercial heating systems are typically larger than residential systems, and their emissions impacts are expected to be proportionally greater per unit. Cost savings may be different due the greater complexity of heating and cooling systems (Tejani & Toshniwal, 2023). Available data on heat pump adoption, on the other hand, typically include both residential and commercial units. Our adoption analysis therefore included both residential and commercial buildings, with greater adoption assumed in the residential sector. 

Air-Conditioning, Heating, and Refrigeration Institute. (2025). AHRI releases November 2024 U.S. heating and cooling equipment shipment data. Link to source: https://www.ahrinet.org/sites/default/files/Stat%20Release%20Nov%2024/November%202024%20Statistical%20Release.pdf 

Asahi, T. (2023, July 3). The role of heat pumps toward decarbonization [PowerPoint slides]. Japan Refrigeration and Air Conditioning Industry Association. Link to source: https://www.jraia.or.jp/english/relations/file/2023_July_OEWG45_JRAIA_side_event_Presentation_4.pdf 

Benz, S. A., & Burney, J. A. (2021). Widespread race and class disparities in surface urban heat extremes across the United States. Earth’s Future, 9(7), Article e2021EF002016. Link to source: https://doi.org/10.1029/2021EF002016 

Bloess, A., Schill, W.-P., & Zerrahn, A. (2018). Power-to-heat for renewable energy integration: A review of technologies, modeling approaches, and flexibility potentials. Applied Energy, 212, 1611–1626. Link to source: https://doi.org/10.1016/j.apenergy.2017.12.073 

Canadian Climate Institute. (2023). Heat pumps pay off [Report]. Link to source: https://climateinstitute.ca/wp-content/uploads/2023/09/Heat-Pumps-Pay-Off-Unlocking-lower-cost-heating-and-cooling-in-Canada-Canadian-Climate-Institute.pdf 

Carella, A., & D’Orazio, A. (2021). The heat pumps for better urban air quality. Sustainable Cities and Society, 75, Article 103314. Link to source: https://doi.org/10.1016/j.scs.2021.103314 

City of Vancouver. (n.d.). Climate change adaptation strategy [Report]. Retrieved September 2, 2025, from Link to source: https://vancouver.ca/files/cov/vancouver-climate-change-adaptation-strategy-2024-25.pdf 

Congedo, P. M., Baglivo, C., D’Agostino, D., & Mazzeo, D. (2023). The impact of climate change on air source heat pumps. Energy Conversion and Management, 276, Article 116554. Link to source: https://doi.org/10.1016/j.enconman.2022.116554 

Cooper, S. J. G., Hammond, G. P., McManus, M. C., & Pudjianto, D. (2016). Detailed simulation of electrical demands due to nationwide adoption of heat pumps, taking account of renewable generation and mitigation. IET Renewable Power Generation, 10(3), 380–387. Link to source: https://doi.org/10.1049/iet-rpg.2015.0127 

Crownhart, C. (2023, February 14). Everything you need to know about the wild world of heat pumps. MIT Technology Review. Link to source: https://www.technologyreview.com/2023/02/14/1068582/everything-you-need-to-know-about-heat-pumps/ 

Davis, L. W., & Hausman, C. (2022). Who will pay for legacy utility costs? Journal of the Association of Environmental and Resource Economists, 9(6), 1047-1085. Link to source: https://doi.org/10.1086/719793 

European Commission. (2022). REPowerEU: Joint European action for more affordable, secure and sustainable energy. Link to source: https://build-up.ec.europa.eu/en/resources-and-tools/publications/repowereu-joint-european-action-more-affordable-secure-and 

European Heat Pump Association. (2024, February 27). Heat pump sales fall by 5% while EU delays action. Link to source: https://www.ehpa.org/news-and-resources/news/heat-pump-sales-fall-by-5-while-eu-delays-action/ 

Gaur, A. S., Fitiwi, D. Z., & Curtis, J. (2021). Heat pumps and our low-carbon future: A comprehensive review. Energy Research & Social Science, 71, Article 101764. Link to source: https://doi.org/10.1016/j.erss.2020.101764 

Gibb, D., Rosenow, J., Lowes, R., & Hewitt, N. J. (2023). Coming in from the cold: Heat pump efficiency at low temperatures. Joule, 7(9), 1939–1942. Link to source: https://doi.org/10.1016/j.joule.2023.08.005 

Global Petrol Prices. (2024). Retail energy price data. Retrieved Feb 2, 2024, from Link to source: https://www.globalpetrolprices.com/ 

Intergovernmental Panel On Climate Change (Ed.). (2023). Climate change 2022: Mitigation of climate change. Working group III contribution to the sixth assessment report of the intergovernmental panel on climate change (1st ed.). Cambridge University Press. Link to source: https://doi.org/10.1017/9781009157926 

International Energy Agency. (2020). Sustainable recovery—World energy outlook special report (revised version). Link to source: https://iea.blob.core.windows.net/assets/c3de5e13-26e8-4e52-8a67-b97aba17f0a2/Sustainable_Recovery.pdf 

International Energy Agency. (2022). The future of heat pumps. Link to source: https://iea.blob.core.windows.net/assets/4713780d-c0ae-4686-8c9b-29e782452695/TheFutureofHeatPumps.pdf 

International Energy Agency. (2023a). Net zero roadmap: A global pathway to keep the 1.5 °C goal in reach—2023 update (revised version). Link to source: https://iea.blob.core.windows.net/assets/8ad619b9-17aa-473d-8a2f-4b90846f5c19/NetZeroRoadmap_AGlobalPathwaytoKeepthe1.5CGoalinReach-2023Update.pdf 

International Energy Agency. (2023b, June 15). Buildings-related energy demand for heating and share by fuel in the Net Zero Scenario 2022-2030. Link to source: https://www.iea.org/data-and-statistics/charts/buildings-related-energy-demand-for-heating-and-share-by-fuel-in-the-net-zero-scenario-2022-2030 

International Energy Agency. (2024). Clean energy market monitor. Link to source: https://iea.blob.core.windows.net/assets/d718c314-c916-47c9-a368-9f8bb38fd9d0/CleanEnergyMarketMonitorMarch2024.pdf 

International Energy Agency. (2025). Electricity 2025 (revised version). Link to source: https://iea.blob.core.windows.net/assets/0f028d5f-26b1-47ca-ad2a-5ca3103d070a/Electricity2025.pdf 

International Gas Union. (2019). Global gas insights 2019 gas & efficiency. Link to source: https://www.igu.org/advocacy/graphics-data/ggi-energy-efficiency 

International Renewable Energy Agency. (2022). Renewable solutions in end-uses: Heat pump costs and markets [Report]. Link to source: https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2022/Nov/IRENA_Heat_Pumps_Costs_Markets_2022.pdf 

International Renewable Energy Agency. (2024). World energy transitions outlook 2024: 1.5°C pathway [Report]. Link to source: https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2024/Nov/IRENA_World_energy_transitions_outlook_2024.pdf 

Jakob, M., Reiter, U., Krishnan, S., Louwen, A., & Junginger, M. (2020). Chapter 11 - Heating and cooling in the built environment. In M. Junginger & A. Louwen (Eds.), Technological learning in the transition to a low-carbon energy system (pp. 189–219). Academic Press. Link to source: https://doi.org/10.1016/B978-0-12-818762-3.00011-X  

Knobloch, F., Hanssen, S. V., Lam, A., Pollitt, H., Salas, P., Chewpreecha, U., Huijbregts, M. A. J., & Mercure, J.-F. (2020). Net emission reductions from electric cars and heat pumps in 59 world regions over time. Nature Sustainability, 3(6), 437–447. Link to source: https://doi.org/10.1038/s41893-020-0488-7 

Malmquist, A., Hjerpe, M., Glaas, E., Karlsson-Larsson, H., & Lassi, T. (2022). Elderly people’s perceptions of heat stress and adaptation to heat: An interview study. International Journal of Environmental Research and Public Health, 19(7), Article 3775. Link to source: https://doi.org/10.3390/ijerph19073775 

Mattiuzzi, C., & Lippi, G. (2020). Worldwide epidemiology of carbon monoxide poisoning. Human & Experimental Toxicology, 39(4), 387-392. Link to source: https://doi.org/10.1177/0960327119891214 

McDiarmid, H. (2023). An analysis of the impacts of all-electric heat pumps and peak mitigation technologies on peak power demand in Ontario [Report]. Ontario Clean Air Alliance. Link to source: https://www.cleanairalliance.org/wp-content/uploads/2023/12/Heat-Pump-Peak-Report-ONLINE-dec-11.pdf 

McDiarmid, H., & Parker, P. (2024). Retrofitting homes in Ontario entails significant embodied emissions: New policies needed. Climate Policy, 25(3), 388–400. Link to source: https://doi.org/10.1080/14693062.2024.2390520 

Renaldi, R., Hall, R., Jamasb, T., & Roskilly, A. P. (2021). Experience rates of low-carbon domestic heating technologies in the United Kingdom. Energy Policy, 156, Article 112387. Link to source: https://doi.org/10.1016/j.enpol.2021.112387 

Romanello, M., Walawender, M., Hsu, S.-C., Moskeland, A., Palmeiro-Silva, Y., Scamman, D., Ali, Z., Ameli, N., Angelova, D., Ayeb-Karlsson, S., Basart, S., Beagley, J., Beggs, P. J., Blanco-Villafuerte, L., Cai, W., Callaghan, M., Campbell-Lendrum, D., Chambers, J. D., Chicmana-Zapata, V., … Costello, A. (2024). The 2024 report of the Lancet Countdown on health and climate change: Facing record-breaking threats from delayed action. The Lancet, 404(10465), 1847–1896. Link to source: https://doi.org/10.1016/S0140-6736(24)01822-1 

Sandoval, N., Harris, C., Reyna, J. L., Fontanini, A. D., Liu, L., Stenger, K., White, P. R., & Landis, A. E. (2024). Achieving equitable space heating electrification: A case study of Los Angeles. Energy and Buildings, 317, Article 114422. Link to source: https://doi.org/10.1016/j.enbuild.2024.114422 

Sovacool, B. K., Evensen, D., Kwan, T. A., & Petit, V. (2023). Building a green future: Examining the job creation potential of electricity, heating, and storage in low-carbon buildings. The Electricity Journal, 36(5), Article 107274. Link to source: https://doi.org/10.1016/j.tej.2023.107274 

Tejani, A., & Toshniwal, V. (2023). Differential energy consumption patterns of HVAC systems in residential and commercial structures: A comparative study. International Journal of Advancements in Science & Technology, 1(3), 47–58. 

U.S. Department of Energy. (2022). Residential cold-climate heat pump technology challenge. Link to source: https://www.energy.gov/eere/buildings/articles/residential-cold-climate-heat-pump-technology-challenge-fact-sheet 

U.S. Department of Energy. (n.d.). Electric resistance heating. Retrieved September 2, 2025, from Link to source: https://www.energy.gov/energysaver/electric-resistance-heating 

U.S. Energy Information Administration. (2023). Updated buildings sector appliance and equipment costs and efficiencies [Report]. Link to source: https://www.eia.gov/analysis/studies/buildings/equipcosts/pdf/full.pdf 

Van Someren, C., Visser, M., & Slootweg, H. (2021). Impacts of electric heat pumps and rooftop solar panels on residential electricity distribution grids. 2021 IEEE PES Innovative Smart Grid Technologies Europe (ISGT Europe), 01–06. Link to source: https://doi.org/10.1109/ISGTEurope52324.2021.9640090 

Wilson, E. J. H., Munankarmi, P., Less, B. D., Reyna, J. L., & Rothgeb, S. (2024). Heat pumps for all? Distributions of the costs and benefits of residential air-source heat pumps in the United States. Joule, 8(4), 1000–1035. Link to source: https://doi.org/10.1016/j.joule.2024.01.022 

Zahiri, S., & Gupta, R. (2023). Examining the risk of summertime overheating in UK social housing dwellings retrofitted with heat pumps. Atmosphere, 14(11), Article 1617. Link to source: https://doi.org/10.3390/atmos14111617 

Zhang, Q., Zhang, L., Nie, J., & Li, Y. (2017). Techno-economic analysis of air source heat pump applied for space heating in northern China. Applied Energy, 207, 533–542. Link to source: https://doi.org/10.1016/j.apenergy.2017.06.083 

Zhou, M., Liu, H., Peng, L., Qin, Y., Chen, D., Zhang, L., & Mauzerall, D. L. (2022). Environmental benefits and household costs of clean heating options in northern China. Nature Sustainability, 5(4), 329–338. Link to source: https://doi.org/10.1038/s41893-021-00837-w 

Credits

Lead Fellow

  • Heather McDiarmid, Ph.D.

Contributors

  • Stephen Agyeman, Ph.D.

  • Ruthie Burrows, Ph.D.

  • James Gerber, Ph.D.

  • Sarah Gleeson, Ph.D.

  • Yusuf Jameel, Ph.D.

  • Daniel Jasper

  • Jason Lam

  • Cameron Roberts, Ph.D.

  • Alex Sweeney

  • Eric Wilczynski

Internal Reviewers

  • Aiyana Bodi

  • Hannah Henkin

  • Jason Lam

  • Zoltan Nagy, Ph.D.

  • Ted Otte

  • Amanda D. Smith, Ph.D.

Effectiveness

Our analysis showed that each all-electric residential heat pump for space heating reduces emissions by an average of 0.95 t CO₂‑eq /heat pump system/yr (20-yr and 100-yr basis, Table 1). 

Heat pumps reduce emissions by reducing the amount of fossil fuels burned for space heating or by reducing the use of less efficient electric resistance heating. Operating a heat pump generates no on-site emissions except refrigerant leaks, which are addressed by the Improve Refrigerant Management solution. Our analysis included the emissions from the electricity used to power heat pumps. Thus, the emissions reduction from heat pump adoption is expected to improve as electricity generation incorporates more renewable energy (Knobloch et al., 2020). 

There are significant regional differences in heat pump effectiveness due to the electricity mix, climate, and types of heating systems used today (Knobloch et al., 2020). The global average is weighted based on regional heating requirements and existing heating technologies. 

We did not quantify the reduction in pollutants such as nitrogen oxides, sulfur oxides, and particulate matter, which are released when fossil fuels are burned for space heating. We also refrained from estimating the global warming impacts of refrigerant leaks associated with the use of heat pumps, which is addressed by our Improve Refrigerant Management solution, or natural gas leaks associated with the use of fossil fuels for heating. 

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Table 1. Effectiveness at reducing emissions from space heating.

Unit: t CO₂‑eq/heat pump system/yr, 100-yr basis

Mean 0.95
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Cost

A residential air-source heat pump has a mean initial installed cost of US$6,800 and an estimated US$540/yr operational cost for heating. Over a 15-year lifespan, this results in a net cost of US$990/yr. A heat pump generally replaces both a heating and cooling system with a combined mean installed cost of US$5,300. Operating a baseline heating system costs US$830/yr (operational cooling cost was not included in this analysis). Over a 15-year lifespan, the baseline case has a net cost of US$1,180/yr. This results in a net US$190 savings for households that switch to a heat pump. This translates to US$200 savings/t CO₂‑eq reduced (Table 2).

These values include the average annual cost to operate the equipment for heating and the annualized up-front cost of a heat pump relative to both a heating and cooling system that it replaces. There can be significant variability in the up-front cost of equipment based on the type of heat pump installed, the size of the building, and the climate in which it is designed to operate. We assumed the cost to operate the equipment for cooling to be the same with heat pumps and the air conditioners they replace. 

There are significant regional differences in the operational cost of heating systems due to climate, utility rates, and the heating systems in use today. The global average outcomes described here are weighted averages from Europe, Canada, the United States, China, and Japan based on regional heating requirements and existing heating technologies. 

Utility cost estimates are from June 2023 (Global Petrol Prices, 2024) and may vary substantially over time due to factors such as volatile fossil fuel prices, changing carbon prices, and heat pump incentives. Additional installation costs, such as upgrades to electrical systems, ductwork, or radiators, are not included. 

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Table 2. Cost per unit climate impact. Negative values reflect cost savings.

Unit: 2023 US$/t CO₂‑eq , 100-yr basis

Mean –200
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Learning Curve

Insufficient data exist to quantify the learning curve for heat pumps. 

The cost of installing a heat pump includes both equipment costs and the labor cost of installation. According to the U.S. Energy Information Administration ([U.S. EIA] 2023), retail equipment costs are 60–80% of the total installed cost of residential air-source heat pumps (central and ductless). 

Equipment costs can decrease with economies of scale and as local markets mature, but may be confounded by technological advances as well as equipment and/or refrigerant regulations that can also increase costs (IEA, 2022). European estimated learning rates for heat pump equipment costs range from 3.3% for ground-source heat pumps (Renaldi et al., 2021) to 18% for air-source heat pumps (Jakob et al., 2020). Ease and cost of installation is a research and development goal for manufacturers (IEA, 2022). 

The installed cost is also affected by rising labor costs and projected labor shortages (IEA, 2022). Renaldi et al. (2021) showed negative learning rates for the total installed costs in the United Kingdom due to increasing installation costs: –2.3% and –0.8% for air-source and ground-source heat pumps, respectively.

Heat pump manufacturer efforts to improve the performance of the technology may impact learning curves as well. In North America, the Residential Heat Pump Technology Challenge has supported the development of heat pumps with improved cold-climate performance (U.S. DOE, 2022). 

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Speed of Action

Speed of action refers to how quickly a climate solution physically affects the atmosphere after it is deployed. This is different from speed of deployment, which is the pace at which solutions are adopted.

At Project Drawdown, we define the speed of action for each climate solution as emergency brake, gradual, or delayed.

Use Heat Pumps is a GRADUAL climate solution. It has a steady, linear impact on the atmosphere. The cumulative effect over time builds as a straight line.

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Caveats

Heat pumps can increase demand for electricity and can therefore increase demand for fossil fuel-based power generation. In areas where power generation relies heavily on fossil fuels, heat pumps may generate more emissions than gas heating systems. As the electricity sector adopts more renewables and phases out fossil fuel-based generation, the emissions impact of heat pumps will decrease. Once a building has been designed or retrofitted to accommodate a heat pump it is likely that new heat pumps will be installed at the end of equipment life, perpetuating the benefit.

Efforts are underway to retrofit buildings by improving insulation, air-sealing, and upgrading windows. When done alongside heat pump adoption, retrofits can reduce the size of heat pump needed and increase total energy, emissions, and cost savings. 

As heat pump adoption grows, so too will the manufacture of refrigerants, some of which have high global warming potentials when they escape to the atmosphere. See Deploy Alternative Refrigerants and Improve Refrigerant Management solutions for more on accelerating change in this sector.

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Current Adoption

Our analysis suggests that 130 million heat pumps for heating are currently in operation primarily based on data in Europe, Canada, the United States, China, and Japan (Table 3). These include both all-electric heat pumps and hybrid heat pumps. The IEA (2023a) estimated that 12% of global space heating demand was met by heat pumps in 2022. 

This value is based on market reports and national data sources plus IEA (2022) estimates of total GW of installed capacity. To convert installed capacity to the number of heat pumps, we used the median from the range of suggested average capacities (7.5 kW for Europe and North America, 4 kW in Japan and China, 5 kW global average). In Japan, where heat pump units typically heat only one room, we assumed 2.4 units per heat pump (International Renewable Energy Agency [IRENA], 2022).

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Table 3. Current heat pump adoption level (2020–2022).

Unit: Heat pump systems in operation

Mean 130,000,000
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Adoption Trend

Our estimates put the median adoption trend at 17 million new all-electric and hybrid heat pumps in operation per year (Table 4). This analysis is based on product shipment data (used as a proxy for installed heat pumps), market reports, national statistics, and IEA data for growth in installed capacity. For the IEA data (2010–2023), we assumed a global average of 5 kW of heat capacity per heat pump unit (IEA, 2024).

Shipment and market analysis reports consistently show growing markets for heat pumps in much of the world (Asahi, 2023; European Heat Pump Association, 2024; IEA, 2024). In the United States, shipments of heat pumps have outnumbered gas furnaces since at least 2022 (Air-Conditioning, Heating, and Refrigeration Institute, 2025).

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Table 4. Heat pump adoption trend (2010–2023).

Unit: Heat pump systems in operation/yr

25th percentile 12,000,000
Mean 15,000,000
Median (50th percentile) 17,000,000
75th percentile 18,000,000
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Adoption Ceiling

Our adoption ceiling is set at 1.200 billion heat pumps for space heating by 2050 (Table 5), most of which are expected to be in residential buildings. This is based on the IEA’s Net Zero Roadmap projection that heat pumps will represent 6,500 GW of heating capacity globally by 2050, covering 55% of space heating demand (IEA, 2023a). Our adoption ceiling assumes all-electric heat pumps cover all space heating demand. 

We assumed that average heat pump sizes (capacities) will increase over time as heat pumps cover a greater portion of a building’s heating load and as more commercial buildings with larger heating loads install heat pumps. Using a global average of 10 kW per heat pump, the IEA projections imply 650 million heat pumps will be in operation by 2050 with the technical adoption ceiling for 1,200 million heat pumps if all heating demand were met by heat pumps.

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Table 5. Heat pump adoption ceiling: upper limit for adoption level.

Unit: Heat pump systems in operation by 2050

Mean 1,200,000,000
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Achievable Adoption

We estimate the achievable range for heat pump adoption to be 600–960 million heat pumps in operation by 2050 (Table 6).

Most existing space heating systems will be replaced at least once between now and 2050 because this equipment typically has lifetimes of 15–30 years (U.S. EIA, 2023). Policies that encourage high efficiency heat pumps alongside insulation upgrades have the potential to provide lifetime savings, greater comfort, and energy efficiency benefits (Wilson et al., 2024). Given the available timelines and potential benefits, near full adoption is technically feasible. 

We have set the Achievable – High heat pump adoption at 80% of the adoption ceiling to account for systems that are difficult to electrify due to very cold climates, policy, economic barriers, and grid constraints. This high achievable value assumes that some systems may be replaced before their end of life to meet climate and/or financial goals. 

We have set the Achievable – Low heat pump adoption at 50% of the adoption ceiling. This is roughly consistent with the current adoption trend continuing out to 2050. 

Our heat pump units adopted include both all-electric and hybrid heat pumps. This analysis assumes that hybrid heat pumps will become less common as fuels are phased out and that all-electric heat pumps will dominate by 2050. 

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Table 6. Range of achievable adoption levels.

Unit: Heat pump systems installed

Current adoption 130,000,000
Achievable – low 600,000,000
Achievable – high 960,000,000
Adoption ceiling 1,200,000,000
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Our estimates show the global impact of existing heat pumps for space heating to be a reduction of 0.12 Gt CO₂‑eq/yr (100- and 20-yr basis) based on current adoption and today’s electricity grid emissions (Table 7). Because electricity grid emissions are decreasing for each kWh of electricity generated (IEA, 2025), the actual impact will be greater than our estimates when future electricity generation emissions are lower.

For the adoption ceiling, assuming heat pumps supply all of the IEA’s projected global heating demand in 2050 (IEA, 2023a), 1.1 Gt CO₂‑eq/yr (100- and 20-yr basis) could be avoided per year with today’s electricity grid emissions.

A high-end achievable target is 80% of the adoption ceiling, accounting for systems that might continue to use fossil fuels for heating due to factors such as cold climates, economic barriers, and grid constraints. This would result in avoiding 0.91 Gt CO₂‑eq/yr (100- and 20-yr basis) with today’s electricity grid emissions. 

A low-end achievable target is 50% of the adoption ceiling, roughly equivalent to heat pump adoption continuing at today’s rate. This would result in avoiding 0.57 Gt CO₂‑eq/yr (100- and 20-yr basis) with today’s electricity grid emissions. 

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Table 7. Climate impact at different levels of heat pump systems adoption.

Unit: Gt CO₂‑eq/yr, 100-yr basis

Current adoption 0.12
Achievable – low 0.57
Achievable – high 0.91
Adoption ceiling 1.1
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Additional Benefits

Heat Stress

Heat waves and extreme heat are becoming increasingly significant factors of morbidity and mortality worldwide (Romanello et al., 2024). Some buildings that replace heating systems with heat pumps will gain access to cooling (Congedo et al., 2023; Wilson et al., 2024; Zhang et al., 2017). This can provide protection from heat stress in regions experiencing increasingly hotter summers (where air conditioning was not previously necessary) and for populations that are vulnerable to heat stress, such as the elderly (Malmquist et al., 2022). Some jurisdictions incentivize heat pumps for this reason. For example, the United Kingdom plans to install 600,000 heat pumps by 2028 (Zahiri & Gupta, 2023), and local climate adaptation plans in Canada recommend the installation of heat pumps to provide space cooling that can reduce morbidity and mortality during heat waves (Canadian Climate Institute, 2023; City of Vancouver, n.d.). Because exposure to extreme heat is disproportionately higher for minority communities – particularly in urban environments – access to cooling has important implications for environmental justice (Benz & Burney, 2021). 

Income and Work

Installing heat pumps can lead to greater household savings on electricity. Research has shown that across the United States, heat pumps can reduce electricity bills for 49 million homes with an average savings of US$350–600 per year, depending on the efficiency of the heat pump (Wilson et al., 2024). Wilson et al. (2024) found that higher efficiency heat pumps could be cost-effective for about 65 million households in the United States. Heat pumps also create jobs (Sovacool et al., 2023). In its post-COVID-19 recovery plan, the IEA (2020) estimated that every US$1 million investment in heat pumps could generate 9.1 new jobs and reduce 0.8 jobs in the fossil fuel industry. About half of the new jobs will be in manufacturing, with the remaining distributed between installation and maintenance.

Health

Burning fossil fuels for heating directly emits health-harming particulates and can generate carbon monoxide. Replacing fossil gas heating with heat pumps can reduce air pollution (Carella & D’Orazio, 2021) and contribute to improving health outcomes (Zhou et al., 2022). A study in China showed that as the power grid moves to incorporate renewable energy, the air quality and health benefits of heat pumps will increasingly outweigh the benefits of gas heaters (Zhou et al., 2022). The risk of carbon monoxide poisoning also decreases in buildings that switch from fuel-burning space heating to heat pumps. In buildings that burn fuels for applications such as space heating, carbon monoxide can pose serious health risks, including poisoning and death (Mattiuzzi & Lippi, 2020). 

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Risks

Heat pumps contain refrigerants that often have high global warming potentials. Refrigerant leaks can occur during installation, operation, and end of life (McDiarmid & Parker, 2024). As more heat pumps are adopted, there is a risk of increased emissions from refrigerant leaks during operation as well as refrigerant release at the end of equipment life. Alternate refrigerants with lower global warming potentials are being phased in due to an international agreement to reduce hydrofluorocarbons, including many refrigerants (Kigali Amendment). 

Higher rates of heat pump installation will require upscaling heat pump manufacturing and training, plus certification of skilled labor to install them. Skilled labor shortages are already creating bottlenecks for heat pump adoption in some countries, some of which can be met by reskilling other heating technicians (IEA, 2022).

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Interactions with Other Solutions

Reinforcing

Advancements in heat pump technology will support the development and adoption of heat pump technology for industrial applications.

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The increased adoption of heat pumps will increase the market for alternative refrigerants and refrigerant management.

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Competing

Heat pumps reduce the emissions from heating and cooling buildings. This reduces the effectiveness of technologies that reduce heating and/or cooling demands.

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Adoption of heat pumps for space heating is likely to generate seasonal peaks in power demand during cold days that may require building out extra generating capacity that decrease grid efficiency (Bloess et al., 2018). Heat pumps can compete with electric cars for power during peak times (Van Someren et al., 2021).

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Dashboard

Solution Basics

heat pump systems

t CO₂-eq (100-yr)/unit/yr
0.95
units
Current 1.3×10⁸ 06×10⁸9.6×10⁸
Achievable (Low to High)

Climate Impact

Gt CO₂-eq (100-yr)/yr
Current 0.12 0.570.91
US$ per t CO₂-eq
-200
Gradual

CO₂ , CH₄, N₂O, BC

Trade-offs

Enhanced grid infrastructure will be required to support widespread building electrification and the greater demand for electricity, especially on cold days when heat pumps are less efficient at moving heat (Cooper et al., 2016). Demand-side management, thermal storage, home batteries, bidirectional chargers, and greater adoption of ground-source heat pumps can all help to reduce this increased demand (Cooper et al., 2016; McDiarmid, 2023).

In general, heat pumps have higher up-front costs than do fueled alternatives but will save a building owner money over the lifetime of the system. This can create economic barriers to accessing the benefits of heat pumps, with low-income homeowners and renters who pay for their utilities being particularly vulnerable to being left behind in the transition (Sandoval et al., 2024). Equity advocates are also concerned that the cost of maintaining gas and other fossil fuel infrastructure may increasingly fall on lower-income building owners who struggle to afford the upfront cost of electrifying with heat pumps (Davis & Hausman, 2022). 

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°C day
015,275

Space heating demand

Heating degree days are a measure of total space heating demand to maintain an indoor temperature above 18 °C.

Fick, S.E. & Hijmans, R.J. (2017). WorldClim 2: new 1km spatial resolution climate surfaces for global land areas (Version 2.1) [Data set]. International Journal of Climatology 37 (12): 4302-4315. Link to source: https://doi.org/10.1002/joc.5086

°C day
015,275

Space heating demand

Heating degree days are a measure of total space heating demand to maintain an indoor temperature above 18 °C.

Fick, S.E. & Hijmans, R.J. (2017). WorldClim 2: new 1km spatial resolution climate surfaces for global land areas (Version 2.1) [Data set]. International Journal of Climatology 37 (12): 4302-4315. Link to source: https://doi.org/10.1002/joc.5086

Maps Introduction

In this solution, heat pumps replace space-heating options that rely on fossil fuels. This primarily applies to North America, Asia, and Europe. Limited data are available for some regions, so this analysis focuses on European countries, Canada, the United States, Japan and China. 

The effectiveness of heat pumps at reducing GHG emissions is influenced by the heating needs of the region and the generation mix of the electricity grid. Areas with higher heating needs will generally show greater emissions reduction because more energy is needed to keep buildings warm. However, this is partially offset because heat pumps are less energy efficient on colder days. The local electricity grid mix matters because heat pumps are powered by electricity. Given the same outside temperature, regions with a largely emissions-free grid (e.g., France or Canada) will have higher emissions impacts from heat pump adoption than areas where electricity is  largely generated from fossil fuels (e.g., China). The type of heat pumps (all-electric vs. hybrid) best suited to each region depends on technological and economic factors.

Action Word
Use
Solution Title
Heat Pumps
Classification
Highly Recommended
Lawmakers and Policymakers
  • Introduce zero-carbon ready building codes, clearly designating heat pumps as the default for all new buildings.
  • Incentivize purchases with grants, loans, or tax rebates.
  • Increasing training and support for heat pump installers.
  • Expand the electrical grid and increase renewable energy generation.
  • Streamline permitting processes.
  • Incentivize complementary solutions such as better insulation, thermal storage, and air sealing.
  • Institute a clean heat standard (similar to a renewable energy standard) with a well-defined implementation timeline.
  • Launch performance labels for heating technology.
  • Roll out new energy efficiency programs.

Further information:

Practitioners
  • Commit to zero-carbon construction, clearly designating heat pumps as the default for all new buildings.
  • Increase the available workforce by encouraging trade organizations to promote career and workforce development programs.
  • Design heat pumps that are simpler, faster, and cheaper to install.
  • Educate customers on the benefits and train them on usage.
  • Connect with users and early adopters to understand and adapt to consumer sentiment.
  • Create appealing incentives and financing programs.
  • Partner with builders and developers to improve product adoption and increase market demand for heat pumps.

Further information:

Business Leaders
  • Commit to zero-carbon construction, clearly designating heat pumps as the default for all new buildings.
  • Deploy heat pumps in all owned and operated facilities.
  • Encourage building owners and managers to switch to heat pumps in leased facilities.
  • Promote the benefits of heat pumps and share government incentives with leased facilities and networks.
  • Encourage employees to reduce emissions at home by providing educational resources on the benefits of domestic heat pumps.

Further information:

Nonprofit Leaders
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Deploy heat pumps in owned and operated facilities.
  • Encourage building owners and managers to switch to heat pumps in leased facilities.
  • Educate businesses and communities on the benefits of installing heat pumps and any tax incentives in their region.
  • Advocate to policymakers for improved policies and incentives.
  • Educate community leaders on the need for adoption.

Further information:

Investors
  • Commit to only finance zero-carbon construction with clear requirements for heat pumps as the default for all new development investments.
  • Deploy capital to efforts that improve heat pump performance and reduce material, installation, and maintenance costs.
  • Explore investment opportunities that address supply chain concerns.
  • Consider investments that mitigate non-manufacturing barriers to scaling.
  • Finance heat pump installations via low-interest loans.

Further information:

Philanthropists and International Aid Agencies
  • Directly distribute heat pumps, prioritizing locations where heat pumps maximize emissions reductions, and improve housing affordability.
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Fund R&D efforts and competitions to improve technology, reduce costs, and address supply chain concerns.
  • Support consumer advocacy and education campaigns on heat pumps and how to maximize regulatory incentives.
  • Support training or incentive programs for distributors and installers.

Further information:

Thought Leaders
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Highlight the need to transition away from fossil-fuel-fired heating.
  • Educate the public on the benefits of heat pumps and how they work.
  • Provide case studies that present successes and lessons learned.
  • Increase consumer comfort by including heat pumps in communication content on topics such as home remodeling and construction, technology, health, self-sufficiency, and personal finance.
  • Provide up-to-date user information on available models.

Further information:

Technologists and Researchers
  • Identify safe, cost-effective, and suitable alternative refrigerants.
  • Design systems that require less refrigerant.
  • Work to increase the longevity of heat pumps.
  • Improve heat pumps’ efficiency and capacity at low temperatures as well as their ability to deliver higher temperature heat.
  • Research external social factors critical to adoption.
  • Identify appropriate methods for recycling and disposing of heat pumps and responsibly recovering their refrigerant chemicals at the end of the product life cycle. 

Further information:

Communities, Households, and Individuals
  • Install heat pumps when possible and encourage local heating, ventilation, and air conditioning (HVAC) retailers and installers to sell services and equipment.
  • Increase consumer comfort by sharing your experience and tips for troubleshooting technologies.
  • Advocate for zero-carbon construction and building codes that clearly designate heat pumps as the default for all new buildings.
  • Build support networks for new users and connect to explore innovations.
  • Encourage your property management company, employers, and government officials to accelerate adoption. 

Further information:

Sources
Evidence Base

Consensus of effectiveness in reducing GHG emissions: High

Electric heat pumps are generally viewed as the primary strategy for reducing GHG emissions from buildings. The Intergovernmental Panel on Climate Change ([IPCC] 2023) noted that heat pumps drive electrification in buildings and help decrease emissions. The European Commission (2022) claimed that heat pumps are an essential way of decreasing reliance on gas in heating while increasing the use of renewable energy in the heating sector. The IEA (2022) reported that heat pumps powered by electricity generated with renewable energy “are the central technology in the global transition to secure and sustainable heating.” IRENA (2024) claimed heat pumps in buildings “will play a crucial role in reducing reliance on fossil fuels.” 

In one of the largest scientific reviews on the topic, Gaur et al. (2021) concluded that heat pumps “have the potential to play a substantial role in the transition to low carbon heating,” and noted that emissions impacts of heat pumps are dependent on the type of heat pump technology, their location, and the electricity grid mix. Knobloch et al. (2020) studied 59 world regions and found that electrification of the heating sector via heat pumps will reduce emissions in most world regions where they are adopted.

The results presented in this document summarize findings from 46 reports, reviews and meta-analyses and 13 original studies reflecting current evidence from 30 countries, primarily European countries, Canada, the United States, Japan, and China. We recognize this limited geographic and technology scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions and in the commercial sector.

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Updated Date

Improve Windows & Glass

Submitted by Drawdown Admin on
Sector
Buildings & Electricity
Mode
Cut Emissions
Cluster
Enhance Efficiency
Image
Building with many windows
Coming Soon
On
Summary

We define the Improve Windows & Glass solution as reducing the heat transferred through typical windows used in residential and nonresidential buildings by improving the thermal insulation capacity of the glass. Windows typically constitute a small portion of a building envelope but account for a substantial portion of the heat transferred (gained or lost) between the indoor space and the external environment. Using double-glazed rather than single-glazed windows cuts GHG emissions by reducing the energy required to heat or cool a building’s interior and improves the thermal comfort of its occupants.

Income & work,Health
Air quality
Description for Social and Search
Improve Windows & Glass is a Highly Recommended climate solution. Upgrading single-glazed windows to double-glazing saves money, improves comfort, and cuts GHG emissions.
Overview

Windows represent 15–40% of a building's total envelope surface area (Shah et al., 2024). A significant amount of the heat transmitted through the building envelope occurs via windows (Basok et al., 2022; Cuce & Riffat, 2015), and the uncontrolled flow of heat due to poor thermal insulation capabilities of windows and glass can generally increase the energy required for heating or cooling indoor spaces by 30–50% (Arasteh et al., 2006; Balali et al., 2023; Gustavsen et al., 2011). Improving windows and glass helps reduce heat gain in warm climates and heat loss in cold climates, thereby reducing the energy required to thermally condition indoor spaces and cutting energy-related emissions while improving occupant comfort.

Operating buildings accounts for approximately 30% of global energy consumption (Delmastro & Chen, 2023). The International Energy Agency (IEA, 2023e) stated that heating indoor spaces accounted for more than 41 EJ of energy in 2022 (an equivalent of about 11,400 TWh). This energy is mainly fossil fuel–based (oil, natural gas, and coal), but also includes electricity, modern bioenergy, and solar thermal (IEA, 2023b; 2023e) (Figure 1). Space cooling is largely achieved through air conditioners. In 2022, cooling buildings used approximately 2,111 TWh (an equivalent of about 8 EJ) (IEA, 2023d; Ritchie, 2024). According to the IEA (2018), annual space-cooling energy consumption in 2016 (2,020 TWh) was more than three times its levels in 1990. Considering the mix of energy sources (IEA, 2023b), this solution potentially cuts CO₂, methane, and nitrous oxide emissions and reduces black carbon and F-gas refrigerant emissions from operating heating and cooling systems (Richardson, 2024; Pistochini et al., 2022).

Figure 1. Energy used in buildings globally largely originates from fossil fuel–based sources.

Source: International Energy Agency. (2023b, June 15). Energy consumption in buildings by fuel in the net zero scenario, 2010-2030.  (adapted from IEA, 2023b)

The properties of a window determine the rate of heat transfer (i.e., its thermal transmittance or U-value) and thus its efficacy at decreasing the flow of heat between the indoors and outdoors (Aguilar-Santana, 2020; Saint-Gobain, 2018). Window types such as double-glazed, double-glazed with low emissivity (low-e) coating, or triple-glazed (Figure 2) perform better than single-glazed windows due to their lower U-values (Aguilar-Santana et al., 2020; Li et al., 2023; Salazar et al., 2024). In more resourced countries or regions such as the United States, Canada, and the European Union, a minimum of double glazing is considered standard practice, accounting for a growing share of the number of windows installed or sold annually (Hermelink et al., 2017; Janssens, 2021). However, the minimum glazing U-value standards set by building energy regulations in most low- and middle-income countries, where the bulk of new construction occurs (IEA, 2023c), often do not mandate the use of better performing windows in buildings (Gaum, 2023). 

The Improve Windows and Glass solution assesses the impact of retrofitting single-glazed windows in the current (2022) global building stock, focusing on scaling up the use of double glazing as the minimum. Retrofitting extends the lifespan of building components and helps these buildings remain in use. The U-value of 2.7 W/m2K we used for double glazing during our analysis also includes other double pane window types with similar U-values such as secondary glazing where a second window is added to the outside of the existing one.

Figure 2. Multiple-glazed windows reduce heat transmission better than single glazed windows and so create less demand for GHG-producing fuels. Modified from Aguilar-Santana et al. (2020) and Moghaddam et al. (2023).

A description of different glazing types.

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Credits

Lead Fellow

  • Henry Igugu, Ph.D.

Contributors

  • Ruthie Burrows, Ph.D.

  • James Gerber, Ph.D.

  • Daniel Jasper

  • Alex Sweeney

Internal Reviewers

  • Sarah Gleeson, Ph.D.

  • Heather McDiarmid, Ph.D.

  • Amanda D. Smith, Ph.D.

Effectiveness

Each 1 m2 of single-glazed window glass in buildings that is upgraded to double glazing has the potential to cut GHG emissions by approximately 0.07 t CO₂‑eq/yr (20-yr and 100-yr basis).

To determine the solution’s effectiveness (Table 1), we evaluated the emissions cut from reducing space heating and space cooling. Since studies often capture different U-value ratings for similar window glass, we weighted the energy saved (kWh/yr) from improving the glass using consistent U-values for the baseline and solution (see Figure 2). Thereafter, we weighted the energy impact by the total area of glass substituted (m2) to determine the savings intensity (kWh/m2/yr) and multiplied the estimate by emission intensities of heating and cooling fuels based on the IEA’s world energy balances data (IEA, 2024).

This solution cuts CO₂, methane, and nitrous oxide emissions by reducing the amount of fossil fuels used for heating and for producing electricity used for cooling. The analysis includes studies from countries representative of heating-dominated and cooling-dominated climates such as the United States (Calautit et al., 2025) and Malaysia (Balasbaneh et al., 2022), respectively. Notably, the solution is also effective in other climates (Magraoui et al., 2025).

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Table 1. Effectiveness at reducing emissions.

Unit: t CO₂‑eq /m2/yr, 100-yr basis

25th percentile 0.043
Mean 0.095
Median (50th percentile) 0.065
75th percentile 0.13
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Cost

Our estimate of the cost per unit climate impact (Table 2) indicates that replacing single-glazed windows with double-glazed windows in buildings globally results in considerable savings of approximately US$123/t CO₂‑eq.

We found that the solution’s initial cost varies considerably, from about US$31/m2 in Malaysia (Balasbaneh et al., 2022) to US$257–684/m2 in France (Harkouss et al., 2018), highlighting regional price differences that could affect adoption. Ultimately, we chose an initial cost of approximately US$144/m2 for double glazing. Using the cost of single glazing we found in studies from different regions (Aruta et al., 2025; Krarti & Ihm, 2016), our analysis determined a baseline initial cost of approximately US$35/m2. While the solution cost is more than four times the baseline, less energy is used for space heating or cooling, reducing the annual operating cost from US$23/m2 to approximately US$12/m2. After amortizing the initial cost over 30 years, the solution resulted in a net savings of US$8/m2/yr, compared with the baseline.

During our analysis, we normalized the initial cost by the baseline and solution U-value (see Figure 2) to ensure consistency. We assumed the initial cost includes the glass component alone, but some of our sources were ambiguous about the scope of the investment and may have also included frames and installation costs. To determine the cost per adoption unit, we weighted the amount of energy consumed for heating and cooling in each data source using the total area of windows upgraded in the respective case study buildings. The analysis does not include revenues because building owners typically do not generate any revenue from window glass installed. 

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Table 2. Cost per unit of climate impact.

Unit: 2023 US$/t CO₂‑eq , 100-yr basis

Median -123
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Learning Curve

We found no definitive data on the solution’s learning rate. While the adoption of double glazing grows, some studies have reported rising cost of glass in recent periods (MLI Building Products, 2023). In an assessment of regional float glass price trends, Procurement Resource (n.d.) argued that rising material, energy, and labor costs amid other economic pressures are driving up the cost of glass. Since modern windows are often made using float glass (Asahi India Glass Ltd., 2025), the initial cost could become more expensive.

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Speed of Action

Speed of action refers to how quickly a climate solution physically affects the atmosphere after it is deployed. This is different from speed of deployment, which is the pace at which solutions are adopted.

At Project Drawdown, we define the speed of action for each climate solution as emergency brake, gradual, or delayed.

Improve Windows and Glass is a GRADUAL climate solution. It has a steady, linear impact on the atmosphere.

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Caveats

Our analysis for this solution focused on the U-value of the glass component alone. It did not include other parameters such as the material type of the window frames or coatings on windows, though these also impact space heating and cooling energy use (Owolabi et al., 2023). We ensured that the data used in our analysis aligned with our approach (i.e., indicated the impact of solely substituting double-glazed or better glass for single-glazed). Due to limited data, we assumed that current adoption in LMICs is 5%. The adoption scenarios and climate impact may be influenced if the actual percentage is higher or lower.

A window’s orientation impacts the solar heat gain. Thus, the influence of upgrading to double-glazing on heating or cooling loads is affected by window placement. We found limited data that incorporates orientation and did not account for this difference.

Recently, some studies have indicated concerns about the payback period of upgrading to double glazing for building owners (Calautit et al., 2025), especially in LMICs, where higher initial costs could be a barrier. Creative initiatives such as incentive schemes can improve the payback period (Aruta et al., 2025). 

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Current Adoption

To determine the current adoption of double-glazed windows, we first estimated the total amount of window glass installed in buildings by applying window-to-floor area ratios from studies to the currently existing 198.1 billion m2 residential and 54.6 billion m2 nonresidential building floor space (IEA, 2023f). This yielded approximately 23.3 billion m2 and 42.2 billion m2 of window glass installed in high-income countries (HICs) and low- and middle-income countries (LMICs), respectively (IEA, 2023c). 

We found limited data for the proportion of minimum double-glazed windows in HICs. The U.S. Energy Information Administration (U.S. EIA, 2023) reported that 80 million housing units (65%) in the U.S. have double-glazed windows installed. Percentages reported for other countries include 88% of housing units in the United Kingdom (Department for Levelling Up, Housing and Communities, 2023), 90% in Canada (Natural Resources Canada, n.d.), and 15% in Australia (Paarhammer, n.d.). Using these percentages, we estimated a 76% (median) solution adoption rate in HICs.

Since we found no definitive data for the solution’s adoption in LMICs, and considering a few LMICs have building energy codes that either mandate or encourage the use of higher performing windows (Gaum, 2023; Gaum & Laubscher, 2022), we assumed that double-glazed windows represent a conservative underestimate of 5%. 

All told, we estimate that as of 2022, installed double-glazed windows in buildings cover roughly 19.9 billion m2 globally (Table 3).

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Table 3. Current (2022) adoption level.

Unit: m2 windows minimum double-glazed

25th percentile 14,300,000,000
Mean 17,100,000,000
Median (50th percentile) 19,900,000,000
75th percentile 22,700,000,000
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Adoption Trend

According to the Department for Levelling Up, Housing and Communities (2023), the percentage of UK homes that have double-glazed windows increased by 9% between 2012 and 2022. Similarly, adoption grew by about 6% in five years (2015–2020) in the United States (U.S. EIA, 2018). Using these countries as representatives, this growth translates to approximately 438–448 million m2 of double-glazed or better windows being added every year in HICs.

We found limited data for adoption trends in LMICs. Based on our assumption for the current adoption in LMICs, we assumed that the percentage adoption of double-glazed windows grew by 4% over 10 years (2012–2022). This assumption, which is likely a conservative underestimate, translates to an annual addition of about 178 million m2/yr of double glazing.

Based on these findings, we estimate that the adoption of double glazing or better windows has grown globally by nearly 622 million m2 annually (Table 4).

Historically, the bulk of the solution’s adoption has occurred in HICs. However, the Global Alliance for Buildings and Construction, IEA, and the United Nations Environment Programme (UNEP) emphasize that adopting double-glazed windows is a necessary sustainability strategy for the building sector, especially in Africa and LMICs (GlobalABC/IEA/UNEP, 2020). This indicates considerable potential for scaling the solution, with 76% of the global building sector’s growth in the past 12 years occurring in LMICs (IEA, 2023f), where there has been less adoption of double glazing or better windows.

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Table 4. 2010–2022 adoption trend.

Unit: m2/yr

25th percentile 620,000,000
Mean 622,000,000
Median (50th percentile) 622,000,000
75th percentile 624,000,000
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Adoption Ceiling

We estimated an adoption ceiling (Table 5) of approximately 46.7 billion m2 of double-glazed windows globally. For this adoption scenario, 90% and 61% of window glass that existed in 2022 will be retrofitted to double-glazed or better by 2050 in HICs buildings and LMICs buildings, respectively.

In our analysis, we used the current double-glazed windows ratio of 90% in Canada (Natural Resources Canada, n.d) as a benchmark for the HICs building sector’s adoption ceiling. For LMICs buildings, we used the IEA’s recommended 2%/yr retrofit rate (IEA, 2022b) over 28 years (2022–2050). This estimated 56% growth was added to the current adoption of 5% to determine the region’s adoption ceiling. The analysis results in about 21 billion m2 and 26 billion m2 of double-glazed windows installed in HICs and LMICs buildings, respectively.

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Table 5. Adoption ceiling.

Unit: m2 windows minimum double-glazed

Estimate 46,700,000,000
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Achievable Adoption

Our analysis estimated a low achievable adoption of approximately 32.9 billion m2 of double-glazed or better windows installed in buildings globally (Table 6). For this scenario, we estimate that the percentage of windows that were at minimum double-glazed as of 2022 in HIC buildings (76%) and LMICs buildings (5%) grows to 81% and 33%, respectively.

Under the high achievable scenario, 86% of window glass in HIC buildings and 47% of window glass in LMICs buildings is at minimum double-glazed. This translates to a total of nearly 40.0 billion m2 of double glazing or better installed by 2050.

The achievable adoption scenarios are largely driven by the growth that is possible in LMICs. We assumed a retrofit rate of 1%/yr for the Achievable – Low scenario, which is the current global retrofit rate in the building industry (IEA, 2022b); for Achievable – High, we used 1.5%/yr. We also assumed that the current (2022) building stock will still be in use by 2050.

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Table 6. Range of achievable adoption levels.

Unit: m2 windows minimum double-glazed

Current adoption 19,900,000,000
Achievable – low 32,900,000,000
Achievable – high 40,000,000,000
Adoption ceiling 46,700,000,000
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The current adoption of double-glazed windows in buildings reduces global GHG emissions by approximately 1.3 Gt CO₂‑eq/yr on a 100-yr and 20-yr basis (Table 7). If the low achievable adoption scenario is reached, this solution could potentially cut about 2.1 Gt CO₂‑eq/yr (100-yr and 20-yr basis). The high achievable scenario would decrease global emissions 2.6 Gt CO₂‑eq/yr year (100-yr and 20-yr basis). We estimated that the adoption ceiling could avoid up to 3.0 Gt CO₂‑eq/yr of emissions on a 100-yr basis (3.1 Gt CO₂‑eq/yr, 20-yr basis).

This solution only accounts for the impact of retrofitting the building stock that exists as of 2022. However, the current global built floor area (252.7 billion m2) is projected to grow by an additional 183 billion m2, by 2050 (IEA, 2022a; 2023b). This means a possible addition of 1.6 billion m2 of new window glass every year, indicating that the potential for scaling the climate impact exists.

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Table 7. Climate impact at different levels of adoption.

Unit: Gt CO₂‑eq/yr, 100-yr basis

Current adoption 1.3
Achievable – low 2.1
Achievable – high 2.6
Adoption ceiling 3.0
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Additional Benefits

Income and Work

While multi-glazed windows are often more of an initial investment than single-pane windows, improved performance of these windows is associated with more energy and cost savings (Menzies & Wherrett, 2005). Regional climates often affect the most appropriate window type and the amount of savings (Karabay & Arici, 2012). In residential buildings, double-glazed windows can add value to homes and increase property values (Aroul & Hansz, 2011). 

Health

Reductions in air pollution due to lower heating and cooling demand decrease exposures to pollutants such as mercury and fine particulate matter generated from fossil fuel–based power plants, improving the health of nearby communities (U.S. Environmental Protection Agency [EPA], 2025). These pollutants have been linked to increased morbidity from cardiovascular and respiratory disease, asthma, infections, and cancer (Gasparotto & Martinello, 2021) and to increased risk of mortality (Henneman et al., 2023). 

Better-performing windows can benefit health through improved thermal comfort (Bulut et al., 2021). When combined with other measures to reduce cooling loads, double-glazed windows can help with the risk of indoor heat stress (Ren et al., 2014). Improved windows may also reduce condensation and mold growth in buildings (Lozinsky et al., 2025). Residents of households with double-glazed windows have reported improvements in noise insulation after retrofitting single-pane windows (Bulut et al., 2021). 

Air Quality

Higher-performing glass can reduce air pollution by lowering gas and electricity demand for heating and cooling, which can decrease pollutants such as CO₂, nitrogen oxides, methane, mercury, and fine particulate matter generated from fossil fuel–based power plants (U.S. EPA, 2025).

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Risks

Faulty installation could compromise the expected benefits of double glazing. It could also lead to condensation on the inner pane if the sealant deteriorates, affecting visibility, aesthetics, and performance and resulting in a potential shorter lifespan than single glazing (Duan et al., 2021; Likins-White, 2023). Additional costs may be incurred when attempting to secure adequate expertise and equipment to ensure proper handling and installation (DIY Double Glaze, n.d.). Depending on the extent of the retrofits, this may drive up construction costs, which is a concern for building developers. However, it also represents opportunities to improve available technical expertise in regions where these services are unavailable or underdeveloped.

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Interactions with Other Solutions

Reinforcing

The Improve Windows and Glass solution reduces the amount of space heating and cooling required. This may reduce the required size and complexity of heating and cooling systems, making them more economically accessible.

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Upgrading window glass can motivate building owners to improve other elements of the building envelope. This could improve the cost efficiency of the upgrades when approached holistically. 

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Competing

The potential climate impact of deploying these solutions could be lower due to the reduced amount of space heating and cooling required in buildings from improving window glass.

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Dashboard

Solution Basics

m2 windows minimum double-glazed

t CO₂-eq (100-yr)/unit/yr
00.040.065
units
Current 1.99×10¹⁰ 03.29×10¹⁰4×10¹⁰
Achievable (Low to High)

Climate Impact

Gt CO₂-eq (100-yr)/yr
Current 1.3 2.12.6
US$ per t CO₂-eq
-123
Gradual

CO₂ , CH₄, N₂O, BC

Trade-offs

Manufacturing double-glazed or better windows generates more industrial sector emissions than does manufacturing single-glazed windows due to the additional materials used. However, life-cycle analysis studies such as Balasbaneh et al. (2022) compared different glazing options ranging from single to triple glazing and determined that the emissions reduced by using better windows outweighs the embodied emissions. Although it is outside the scope of this solution, window frames account for as much as 46–80% of a window's embodied emissions, especially when using conventional window frame materials such as polyvinyl chloride and aluminum (Saadatian et al., 2021). Despite the higher embodied emissions, the emissions reductions from implementing the solution are substantial.

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Action Word
Improve
Solution Title
Windows & Glass
Classification
Highly Recommended
Lawmakers and Policymakers
  • Set clear and measurable targets for building efficiency, emissions reduction, and the deployment of improved windows.
  • Enact holistic policy plans and building codes to reduce GHG emissions from buildings through improved windows and framing systems.
  • Set public procurement standards for windows and glass, using double-glazed windows, at minimum, for public buildings.
  • Amend building codes to include minimum requirements based on window performance; gradually increase the standards over time if necessary.
  • Periodically update codes, policies, and public guidance to keep pace with research and development.
  • Make double-glazed windows the minimum standard option through a range of policy interventions, including regulations, subsidies, and educational programs where relevant; extend incentives to high performing secondary-, double- or triple-glazed windows, if relevant.
  • Offer financial incentives such as subsidies, tax credits, and grants for consumers, manufacturers, start-ups, and improved window installers.
  • Ensure financial incentives reach, and offer additional incentives for, low- and middle-income communities.
  • Ensure financial incentives cover both new installations and retrofits.
  • Create financial disincentives such as higher taxes and fines for lower performing windows.
  • Subsidize workforce or skills development and/or work with businesses to identify gaps and needs such as technical knowledge or the advantages of new technology.
  • Invest in research and development to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Create green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.
  • Offer educational resources, one-stop shops for windows, and demonstrations for installation and retrofits; offer tours of model builds that feature improved windows for commercial and private developers, highlighting the cost savings, and environmental benefits.

Further information:

Practitioners
  • Finance or develop only new construction and retrofits that use improved windows and other low-carbon practices.
  • Take advantage of financial incentives such as subsidies, tax credits, and grants for installing improved windows.
  • Seek or negotiate preferential loan agreements for developers using improved windows and other climate-friendly practices.
  • Use double-glazed windows as the most basic standard and offer a variety of better-performing options such as triple-glazed.
  • Work with designers and architects who integrate efficient windows and other efficient materials into their designs.
  • Integrate improved window designs into construction databases, including listing prices, thermal insulation properties, and environmental benefits.
  • Advocate for financial incentives, improved building codes, and educational programs advancing the use of improved windows.
  • Use educational resources, one-stop shops for retrofitting and weatherization, installation demonstrations, and tours of model builds.
  • Conduct research to improve the manufacturing, adoption, supply chain access, and circularity of windows.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for improving windows.

Further information:

Business Leaders
  • Finance only new construction and retrofits that use improved windows and other low-carbon practices.
  • Expand product lines to include improved window designs.
  • Integrate improved window designs into construction databases, listing prices, thermal insulation properties, and environmental benefits.
  • Invest in research and development to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Advocate for financial incentives, improved building codes, and educational programs advancing the use of improved windows.
  • Join green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.
  • Create long-term purchasing agreements with improved window manufacturers to support stable demand and improve economies of scale.
  • Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Nonprofit Leaders
  • Finance or develop only new construction and retrofits that use improved windows and other low-carbon practices.
  • Advocate for clear and measurable public targets for building efficiency, emissions reduction, and deployment of improved windows.
  • Advocate for holistic policy plans and building codes to reduce GHG emissions from buildings that include improved windows and framing systems.
  • Advocate for financial incentives, improved building codes, and educational programs advancing the use of improved windows.
  • Conduct research to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Work with businesses for workforce or skills development.
  • Offer educational resources, one-stop shops for windows, and demonstrations for installation and retrofits; offer tours of model builds that feature improved windows for commercial and private developers, highlighting the cost savings and environmental benefits.
  • Create, join, or administer green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Investors
  • Finance only new construction and retrofits that use improved windows and other low-carbon practices.
  • Invest in research and development and start-ups to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Issue green bonds to invest in projects that use improved windows and integrate other climate-friendly construction practices.
  • Offer preferential loan agreements for developers using improved windows and other climate-friendly practices.
  • Join green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Philanthropists and International Aid Agencies
  • Finance only new construction and retrofits that use improved windows and other low-carbon practices.
  • Offer grants for developers using improved windows and other climate-friendly practices.
  • Create financing programs for private construction in low-income or under-resourced communities requiring the use of improved windows.
  • Advocate for clear and measurable public targets for building efficiency, emissions reduction, and the deployment of improved windows.
  • Advocate for holistic policy plans and building codes to reduce GHG emissions from buildings that include improved windows and framing systems.
  • Advocate for financial incentives, improved building codes, and educational programs for improved windows.
  • Fund research to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Offer educational resources, one-stop shops for retrofitting and weatherization, installation demonstrations, and tours of model builds for commercial and private developers, highlighting the cost savings and environmental benefits.
  • Create, join, or administer green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Thought Leaders
  • Advocate for clear and measurable public targets for building efficiency, emissions reduction, and the deployment of improved windows.
  • Advocate for holistic policy plans and building codes to reduce GHG emissions from buildings that include improved windows and framing systems.
  • Advocate for financial incentives, improved building codes, and educational programs for improved windows.
  • Conduct research to improve window design, manufacturing, adoption, supply chain access, and circularity.
  • Contract with businesses for workforce or skills development.
  • Offer or support educational resources, one-stop shops for retrofitting and weatherization, installation demonstrations, and tours of model builds for commercial and private developers, highlighting the cost savings and environmental benefits of improved windows.
  • Create, join, or administer green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Technologists and Researchers
  • Research and develop high-performance window technologies such as vacuum glazing, aerogel applications, potential integration of solar photovoltaic glass, and the use of unconventional gases to fill multi-pane windows and improve performance.
  • Create improved alternatives to common practices for air and vapor sealing.
  • Find alternative materials for spacers with reduced thermal conductivity in double- and triple-glazed windows.
  • Research and develop alternative window frame designs to improve thermal performance, structural insulating materials, and improve ease of installation (e.g., out-of-the-box window installation kits).
  • Improve efficiency of the window manufacturing process, supply chain access, and the circular economy of glass.

Further information:

Communities, Households, and Individuals
  • Finance or develop only new construction and retrofits that use improved windows and other low-carbon practices.
  • Take advantage of financial incentives such as subsidies, tax credits, and grants for installing improved windows.
  • Advocate for clear and measurable public targets for building efficiency, emissions reduction, and the deployment of improved windows.
  • Advocate for holistic policy plans and building codes to reduce GHG emissions from buildings that include improved windows and framing systems.
  • Advocate for financial incentives, improved building codes, and educational programs for improved windows.
  • Organize local “green home tours” and open houses to showcase climate-friendly builds, fostering demand by highlighting cost savings and environmental benefits of improved windows.
  • Capture community feedback and share it with local policymakers to address barriers such as permitting logistics or up-front costs, helping to shape policies that drive adoption.
  • Create, join, or administer green building certification schemes and/or public-private partnerships that offer information, training, and general support for improved windows.

Further information:

Sources
Evidence Base

Consensus of effectiveness in reducing GHG emissions: High

Improving windows and glass helps optimize the amount of heating required in buildings by reducing heat loss. Calautit et al. (2025) reported that energy used for heating in a United Kingdom residence dropped nearly 23% after reducing the glass U-value from 5.6 W/m2K to 2.8 W/m2K. Using the same building parameters, the study tested the impact of reducing the U-value by 1.35 W/m2K in the climatic conditions of Netherlands, Japan, United States, Sweden and Australia. The outcomes were similar, with about a 10–12% reduction in heating loads (Calautit et al., 2025). The results from Yuk et al. (2024), Magraoui et al. (2025), and Ahmed et al. (2025) further support these findings. 

Similarly, the solution reduces heat gained from the outdoors into buildings, thereby cutting cooling loads. Gomaa et al. (2025) reported that energy use in a Saudi Arabian residence was reduced by 1,265 kWh/yr (49%) after improving the glass U-value from 5.6 to 0.9 W/m2K (84%). Es-sakali et al. (2022) recorded 36% less electricity consumed after reducing the U-value by 1.44 W/m2K in Morocco’s climate.

The results presented in this document summarize findings from 10 original studies reflecting current evidence from 13 countries. We recognize this limited geographic scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions. The studies we found used simulations to assess the impact of retrofitting windows due to the inherent difficulty of real-world experiments. However, we used studies that include field measurements and calibration of the building simulations to validate their models.

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Updated Date
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