Deploy Alternative Insulation Materials is defined as using alternative building insulation materials in place of conventional ones. In particular, we highlight the impact of using cellulose instead of glass, mineral, or plastic insulation in new and retrofit buildings. Cellulose insulation manufacture and installation emits fewer GHGs to reach the same operational insulating performance than does manufacture and installation of conventional materials.
Thermal insulation materials are used in the walls, roofs, and floors of buildings to help maintain comfortable indoor temperatures. However, manufacture and installation of insulation materials produces GHG emissions. These are called embodied emissions because they occur before the insulation is used in buildings. Insulation embodied emissions offset a portion of the positive climate impacts from using insulation to reduce heating and cooling demand. A Canadian study found that over 25% of residential embodied emissions from manufacturing building materials can be due to insulation (Magwood et al., 2022). Using cellulose insulation made primarily from recycled paper avoids some embodied emissions associated with conventional insulation.
Insulation is manufactured in many different forms, including continuous blankets or boards, loose fill, and sprayed foam (Types of Insulation, n.d.). Most conventional insulation materials are nonrenewable inorganic materials such as stone wool and fiberglass. These require high temperatures (>1,300 °C) to melt the raw ingredients, consuming thermal energy and releasing CO₂
from fossil fuel combustion or grid power generation (Schiavoni et al., 2016). Other common insulations are plastics, including expanded polystyrene (EPS), extruded polystyrene (XPS), polyurethane (PUR), and polyisocyanurate (PIR). Producing these plastics requires the extraction of fossil fuels – primarily petroleum – for feedstocks, as well as high amounts of energy for processing (Harvey, 2007).
F-gases are often used as blowing agents to manufacture rigid foam board insulation or install sprayed foam insulation (Figure 1). F-gases are GHGs with GWPs that can be hundreds or thousands of times higher than CO₂.
High-GWP F-gases used in foam production are released into the atmosphere during all subsequent stages of the foam’s life cycle (Biswas et al., 2016; Waldman et al., 2023). The climate benefits of this solution during the installation stage are primarily due to avoiding these blowing agents.
Alternative insulation is produced from plant or animal biomass (bio-based materials, see Figure 2) or waste products (recycled materials). Alternative insulation materials provide climate benefits by consuming less manufacturing energy, using renewable materials in place of fossil fuels, and eliminating high-GWP blowing agents (Sustainable Traditional Buildings Alliance, 2024).
Figure 3compares a variety of conventional and alternative insulation materials. While many bio-based and recycled materials could be used as alternatives to these conventional materials, this solution focuses on cellulose due to its effectiveness in avoiding emissions, low cost, and wide availability. Cellulose insulation is made primarily from recycled paper fibers, newsprint, and cardboard. These products are made into fibers and blended with fire retardants to produce loose or batt cellulose insulation (Figure 4) (Waldman et al., 2023; Wilson, 2021).
Figure 1. Properties and adoption of conventional and alternative insulation materials. Costs and emissions will vary from the values here depending on the insulation form (board, blanket, loose-fill, etc.).
Category
Material
High-GWP F-gases used?
Median manufacturing and installation emissions*
Mean product and installation cost**
Estimated market share (% by mass)
Conventional materials
Stone wool
No
0.31
623
20
Glass wool (fiberglass)
No
0.29
508
34
EPS
No
0.38
678
22
XPS
Yes, sometimes
9.44
702
7
PUR/PIR
Yes, sometimes
6.14
1,000
11
Alternative materials
Cellulose
No
0.05
441
2–13
Cork
No
0.30
1,520
Commercially available, not widely used
Wood fiber
No
0.13
814
Commercially available, not widely used
Plant fibers (kenaf, hemp, jute)
No
0.18
467
Commercially available, not widely used
Sheep’s wool
No
0.14
800
Commercially available, not widely used
Recycled PET plastic
No
0.12
2,950
Commercially available, not widely used
*t CO₂‑eq
(100-yr) to insulate 100m² to 1m²·K/W
**2023 US$ to insulate 100m² to 1m²·K/W. We use mean values for cost analysis to better capture the limited data and wide range of reported costs.
Although we are estimating the impact of using cellulose insulation in all buildings, the unique circumstances of each building are important when choosing the most appropriate insulation material. In this solution, we don’t distinguish between residential and commercial buildings, retrofit or new construction, different building codes, or different climates, but these would be important areas of future study.
In this solution, the effectiveness, cost, and adoption are calculated over a specified area (100 m2) and thermal resistance (1 m2·K/W). The chosen adoption unit ensures that all data are for materials with the same insulating performance. Due to limited material information, we assumed that insulation mass scales linearly with thermal resistance.
To better understand the adoption unit, a one-story residential building of 130 m2 floor area would require approximately 370 m2 of insulation area (RSMeans from The Gordian Group, 2023). For a cold climate like Helsinki, Finland, code requires insulation thermal resistance of 11 m2·K/W (The World Bank, n.d.). For a warm climate like Jerusalem, Israel, envelope thermal resistance requirements average 1.1 m2·K/W (The World Bank, n.d.). Therefore, depending on the location, anywhere from approximately 4–40 adoption units insulating 100 m2 to 1 m2·K/W may be needed to insulate a small single-story home to the appropriate area and insulation level.
Take Action Intro
Would you like to help deploy alternative insulation? Below are some ways you can make a difference, depending on the roles you play in your professional or personal life.
These actions are meant to be starting points for involvement and may or may not be the most important, impactful, or doable actions you can take. We encourage you to explore, get creative, and take a step that is right for you!
To insulate 100 m2 to a thermal resistance of 1 m2·K/W using entirely cellulose insulation in place of the current baseline mix of insulation materials is expected to avoid 1.59 t CO₂‑eq
on a 100-yr basis (Table 1). Effectiveness for this solution measures the one-time reduced emissions from manufacturing and installing insulation. Insulation also reduces the energy used while a building is operating, but those emissions are addressed separately in the Improve Building Envelopes solution.
Conventional insulation cost was considered to be a weighted average cost of the current baseline insulation mix, including a small amount of cellulose insulation currently in use.
The largest contributor to conventional insulation embodied emissions is using high-GWP blowing agents to manufacture or install XPS, PUR, or PIR foam. We assumed the use of F-gas blowing agents for all foams, although these are already being regulated out of use globally (Amendment to the Montreal Protocol on Substances That Deplete the Ozone Layer, 2016) and an unknown amount of low-GWP blowing agents are currently use (such as hydrocarbons or CO₂
). Therefore, we anticipate the effectiveness of this solution will decrease as F-gases are used less in the future. We assumed that 100% of blowing agents are emitted over the product lifetime.
Cellulose has the greatest avoided emissions of all of the alternative materials we evaluated (Figure 1). The next most effective materials were recycled PET, wood fibers, and sheep’s wool. Conventional materials like XPS, PUR, and PIR that are foamed with F-gases had the highest GHG emissions. For bio-based materials, we did not consider biogenic carbon as a source of carbon sequestration due to quantification and permanence concerns.
left_text_column_width
Table 1. Effectiveness at reducing emissions.
Unit: t CO₂‑eq
/insulation required to insulate 100 m2 to a thermal resistance of 1 m2·K/W, 100-yr basis
25th percentile
0.98
mean
1.34
median (50th percentile)
1.59
75th percentile
1.81
Left Text Column Width
Cost
Available cost data are variable for all materials, particularly those in early-stage commercialization. The mean cost of purchasing and installing cellulose insulation is less than that of any other conventional or alternative insulation material (Figure 1). Compared with the average cost of conventional insulation, the mean cost savings for cellulose insulation is US$193/100 m2 insulated to a thermal resistance of 1 m2·K/W. Since most buildings are insulated over greater areas to higher thermal resistances, these savings would quickly add up. When considering the mean cost per median climate impact, cellulose insulation saves US$121/t CO₂‑eq
(100-yr basis), making it an economically and environmentally beneficial alternative (Table 2).
We considered conventional insulation cost to be a weighted average cost of the current baseline insulation mix, including a small amount of cellulose insulation currently in use.
For conventional insulation, material costs of purchasing the insulation are higher than costs for installation (US$540 and US$97, respectively, to insulate 100 m2 to a thermal resistance of 1 m2·K/W). Cellulose has a lower product cost and comparable installation costs to conventional materials. We considered all costs to be up-front and not spread over the lifetime of the material or building. For each material type, cost will vary based on the form of the insulation (board, loose, etc.) and this should be accounted for when comparing insulation options for a particular building.
We determined net costs of insulation materials by adding the mean cost to purchase the product and the best estimation of installation costs based on available information. Installation costs were challenging to find data on and therefore represent broad assumptions of installation type and labor. Cost savings were determined by subtracting the weighted average net cost of conventional materials to the net cost of an alternative material. Although we used median values for other sections of this assessment, the spread of data was large for product cost estimates and the mean value was more appropriate in the expert judgment of our reviewers.
left_text_column_width
Table 2. Cost per unit of climate impact.
Unit: 2023 US$/t CO₂‑eq, 100-yr basis
estimate
-121
Left Text Column Width
Learning Curve
Little information is available about the learning rate for new insulation materials. Mályusz and Pém (2013) evaluated how labor time decreased with repetitive cycles for installing roof insulation. They found a learning rate of ~90%, but only for this specific insulation scenario, location, and material. Additionally, this study does not include any product or manufacturing costs that may decrease with scale.
In general, labor time for construction projects decreases with repetitive installation, including improved equipment and techniques and increased construction crew familiarity with the process (SaravanaPrabhu & Vidjeapriya, 2021). However, Malhotra and Schmidt (2020) classify building envelope retrofits as technologies that are highly customized based on user requirements, regulations, physical conditions, and building designs, likely leading to learning rates that are slow globally but where local expertise could reduce installation costs.
left_text_column_width
Speed of Action
Speed of action refers to how quickly a climate solution physicallyaffects 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 gradual, emergency brake, or delayed.
Deploy Alternative Insulation Materials is an EMERGENCY BRAKE climate solution. It has the potential to deliver a more rapid impact than nominal and delayed solutions. Because emergency brake solutions can deliver their climate benefits quickly, they can help accelerate our efforts to address dangerous levels of climate change. For this reason, they are a high priority.
left_text_column_width
Caveats
Manufacturing and installation emissions reductions due to the use of alternative building thermal insulation materials are both permanent and additional.
Permanence: There is a low risk of the emissions reductions for this solution being reversed. By using cellulose insulation instead of inorganic or plastic-based insulation, a portion of the manufacturing and installation emissions are never generated in the first place, making this a permanent reduction. Emissions from high-temperature manufacturing, petroleum extraction, and blowing agent use are all reduced through this approach.
Additionality: The GHG emissions reductions from alternative insulation materials are additional because they are calculated here relative to a baseline insulation case. This includes a small amount of cellulose materials included in baseline building insulation. Therefore, avoided emissions represent an improvement of the current emissions baseline that would have occurred in the absence of this solution.
left_text_column_width
Current Adoption
Adoption data are extremely limited for alternative insulation materials. All adoption data and estimates are assumed to apply to both residential and commercial buildings, although in reality the uptake of alternative insulation materials will vary by building type due to differences in structures, climate, use type, and regulations. We assume that future uptake of alternative insulation is used only during retrofit or new construction, or when existing insulation is at the end of its functional lifetime.
European sources report that 2–13% of the insulation market is alternative materials. Depending on the source, this could include renewable materials, bio-based insulation, or recycled materials. In 2018 in the United States, 5% of total insulation area in new single-family homes was insulated with cellulose (Insulation Choices Revealed in New Study, 2019).
To convert estimated cellulose adoption percentage into annual insulation use, we estimated 26 Mt of all installed global insulation materials in 2023 based on a report from The Freedonia Group (2024). We calculated an annual use of approximately 1.7 billion insulation units of 100 m2 at a thermal resistance of 1 m2·K/W. Therefore, the median cellulose adoption is 140 million units/yr at 100 m2 at 1 m2·K/W, calculated from the median of the 2–13% adoption range.
Since this calculation is based on more alternative materials than just cellulose and is heavily reliant on European data where we assume adoption is higher, this estimate of current adoption (Table 3) is most likely an overestimate.
The little adoption data that were considered in this section are mostly for Europe, and some for the United States. We recognize this limited geographic scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions.
left_text_column_width
Table 3. Current (2017–2022) adoption level.
Unit: units of insulation/yr installed to insulate 100 m2 to a thermal resistance of 1 m2·K/W
25th percentile
9000000
mean
130000000
median (50th percentile)
140000000
75th percentile
170000000
Left Text Column Width
Adoption Trend
Very few data are available that quantify adoption trends. In a regional study of several bio-based insulation materials, Rabbat et al. (2022) estimated French market annual growth rates of 4–10%, with cellulose estimated at 10%. Petcu et al. (2023) estimated the European adoption of recycled plastic and textile insulation, biomass fiber insulation, and waste-based insulation to have increased from 6% to 10% between 2012 and 2020.
When accounting for the calculated current adoption, these growth rates mean a median estimated annual increase of 500,000 insulation units/yr required to insulate 100 m2 to a thermal resistance of 1 m2·K/W. The increasing adoption of biobased insulation decreases the use of conventional insulation materials in those regions.
This adoption trend (Table 4) is likely an overestimate, as it is biased by high European market numbers and based on the likely high estimate we made for current adoption.
left_text_column_width
Table 4. 2012–2020 adoption trend.
Unit: annual change in units of insulation/yr installed to insulate 100 m2 to a thermal resistance of 1 m2·K/W
For cellulose insulation, availability does not seem to limit adoption. The Food and Agriculture Organization of the United Nations (2023) reports that there is a much higher annual production of cellulose-based materials (>300 Mt annually of cartonboard, newsprint, and recycled paper) than the overall demand for insulation globally (>25 Mt annual demand; Global Insulation Report, 2024). However, other uses for cellulose products may create competition for this supply.
Increased thickness of insulation could also be a limiting factor since this would reduce adoption by decreasing building square footage, in particular making retrofits more challenging and expensive. Deer et al. (2007) reported that the average cellulose thermal resistance is similar to mineral and glass wool, and lower than plastic insulations made of polystyrene and other foams. If we assume that 50% of plastic insulation cannot be replaced with cellulose due to thickness limitations, this would represent ~20% of current insulation that could not be replaced without structural changes to the building. Therefore, we calculate the adoption ceiling to be 80% of the current insulation that would be reasonably replaceable or 140 million units/yr required to insulate 100 m2 to a thermal resistance of 1 m2·K/W (Table 5).
Uptake of celllose insulation could also be limited by its susceptibility to absorbing moisture, limiting its use in wet climates or structures that retain moisture, such as flat roofs. Commercialization of alternative insulation materials beyond cellulose and in many different forms (e.g., board, loose-fill) will increase the adoption ceiling across more building types.
left_text_column_width
Table 5. Adoption ceiling.
Unit: units of insulation installed to insulate 100 m2 to a thermal resistance of 1 m2·K/W/yr.
25th percentile
N/A
mean
N/A
median (50th percentile)
140000000 (estimate)
75th percentile
N/A
Left Text Column Width
Achievable Adoption
No estimates have been found for feasible global adoption of this solution. Rabbat et al. (2022) estimated the adoption levels of several bio-based insulation materials in France in 2050. For cellulose wadding, this was estimated to be 2.1 times the commercialized volume in France in 2020. Although we do not expect France to be representative of the rest of the world, if the predicted adoption trend holds across the world then we expect low adoption in 2050 to be 2.1 times greater than 2023 adoption. This is 29 million units/yr to insulate 100 m2 to a thermal resistance of 1 m2·K/W (Table 6).
The IEA (2023) claims that building envelopes need to have their retrofit rate increase by 2.5 times over the current rate in order to meet net zero targets (2023). This is a reasonable high-adoption scenario. Assuming that more retrofits of buildings occur and greater amounts of alternative insulation are installed in new buildings, we estimate that high future adoption of new insulation could occur at 2.5 times the rate of the low-adoption scenario. This is 73 million units/yr to insulate 100 m2 to a thermal resistance of 1 m2·K/W (Table 6).
Adoption will be facilitated or limited by local regulations around the world. Building codes will determine the location and extent of use of cellulose or other bio-based insulation. We expect uptake to be different between residential and commercial buildings, but due to insufficient data, we have grouped them in our adoption estimates.
left_text_column_width
Table 6. Range of achievable adoption levels.
Unit: units of insulation installed to insulate 100 m2 to a thermal resistance of 1 m2·K/W/yr
Current Adoption
14000000
Achievable – Low
29000000
Achievable – High
73000000
Adoption Ceiling
140000000
Left Text Column Width
The climate impacts for this solution are modest compared to current global GHG emissions. Not all conventional insulations have a high environmental impact due to the use of a wide range of materials, forms, and installation methods as well as the recent adoption of lower-GWP blowing agents. Therefore, the potential for further emissions savings is limited.
We quantified the effectiveness and adoption of cellulose insulation, which has the lowest emissions and, therefore, the highest climate impacts of the insulation materials we evaluated. With high adoption, 1.2 Gt CO₂‑eq
on a 100-yr basis could be avoided over the next decade (Table 7).
While we only considered the adoption of cellulose insulation in this analysis, a realistic future for lowering the climate impact of insulation may include other bio-based materials, too. Utilizing a greater range of materials should increase adoption and climate impact due to more available forms, sources, and thermal resistance values of bio-based insulation.
Note that the current climate impact is calculated using a current materials baseline that includes a small fraction of cellulose. This means that the reported current adoption impact is a slight underestimate compared with the impacts for replacing entirely conventional insulation with the current amount of cellulose insulation in use.
left_text_column_width
Table 7. Climate impact at different levels of adoption.
Unit: Gt CO₂‑eq/yr,
100-yr basis
Current Adoption
0.022
Achievable – High
0.046
Achievable – Low
0.12
Achievable Ceiling
0.22
Left Text Column Width
Sign up for our newsletter today and be among the first to hear about Drawdown Explorer updates.
Additional Benefits
Income & Work
Some alternative insulations can be cheaper than conventional materials. Although there is large variation in evaluation methods and reported costs, our analysis found that cellulose and plant fibers are cheaper than conventional insulation materials such as stone wool, glass wool, and EPS (Figure 1). Depending on the applicable climate conditions and insulation form, switching to alternative insulation materials can result in cost savings for consumers, including homeowners and business owners.
Health
Conventional insulation materials may contribute to poor indoor air quality, especially during installation, and contribute to eye, skin, and lung irritation (Naldzhiev et al., 2020; Stamm et al., 2022; Wi et al., 2021). Additionally, off-gassing of flame retardants and other volatile organic compounds and by-products of conventional insulation can occur shortly after installation (Naldzhiev et al., 2020). Using bio-based alternative insulation products can minimize the health risks during and after installation (McGrath et al., 2023).
Water Resources
Although there is not a scientifically consistent approach to compare the environmental impacts of conventional and alternative insulation materials, a review analysis of 47 studies on insulation concluded that bio-based insulation materials generally have lower impacts as measured through acidification, eutrophication, and photochemical ozone creation potentials compared than do conventional materials (Füchsl et al., 2022). Other alternative materials such as wood fiber and miscanthus also tend to have a lower environmental footprint (Schulte et al., 2021). The water demand for wood and cellulose is significantly lower than that for EPS (about 2.8 and 20.8 l/kg respectively compared with 192.7 l/kg for EPS) (Zabalza Bribián et al., 2011). While the limited evidence suggests that the alternative material tends to be better environmentally, there is an urgent need to conduct life cycle assessments using a consistent approach to estimate the impact of these materials.
left_text_column_width
Risks
Cellulose insulation is susceptible to water absorption, which can lead to mold growth in wet or humid environments (Andersen & Rasmussen, 2025; Petcu et al., 2023). Mitigating this risk either requires an antifungal treatment for the material or limits adoption to particular climates. The thermal performance of cellulose insulation can decrease over time due to water absorption, settling, or temperature changes, but installing it as dense-packed or damp-spray can mitigate this (Wang & Wang, 2023; Wilson, 2021).
Bio-based insulation materials tend to be combustible, meaning they contribute more to the spread of a fire than non-combustible stone or glass insulation. Some bio-based materials are classified as having minimal contribution to a fire, such as some cellulose forms, rice husk, and flax (Kumar et al., 2020). These materials are less likely to contribute to a fire than very combustible plastic insulation such as EPS, XPS, and PUR. Fire codes – as well as other building and energy codes – could limit adoption, risking a lack of solution uptake due to regulatory setbacks (Northeast Bio-Based Materials Collective 2023 Summit Proceedings, 2023).
Additives such as fire retardants and anti-fungal agents are added to bio-based insulation along with synthetic binders, which can lead to indoor air pollution from organic compounds, although likely in low concentrations (Maskell et al., 2015; Rabbat et al., 2022).
left_text_column_width
Interactions with Other Solutions
Reinforcing
Upgrading insulation to lower-cost and lower-emitting alternative materials should increase the adoption of other building envelope solutions as they can be installed simultaneously to optimize cost and performance.
The use of biomass as raw material for insulation will reduce the availability and increase the cost of using it for other applications. For cellulose, global production of cellulose materials (>300 Mt annually of cartonboard, newsprint, and recycled paper (Forestry Production and Trade, 2023)) is an order of magnitude higher than the demand for insulation materials (>25 Mt annual demand (The Freedonia Group, 2024)), so the overall impact should be small.
Reducing the demand for conventional insulation products and instead making insulation that produces fewer GHGs during manufacturing would slightly reduce the global climate impact of other industrial manufacturing solutions. This is because less energy overall would be used for manufacturing, and therefore other technologies for emissions reductions would be less impactful for insulation production.
Unit used to measure how much the solution is being used or practiced. The adoption unit serves as a metric for calculating the impact of the solution.
(insulation units of 100 m2 and 1 m2·K/W)/yr
t CO₂-eq/unit
The amount of emissions (in CO₂‑eq
) reduced or removed from the atmosphere per adoption unit. These values are sometimes reported in tons CO₂‑eq
reduced or removed per year.
Cost for mitigation when a solution is implemented, in U.S. dollars, adjusted for inflation to 2023. Costs and emissions are estimated relative to 2023 baseline activities. When applicable, costs include initial and operating expenditures minus revenues. Negative values indicate cost savings.
How quickly a climate solution physically affects the atmosphere after it is deployed. This depends on how effective the greenhouse gases are at trapping heat in the atmosphere and whether the solution changes carbon dioxide removal.
Gases or particles that have a planet-warming effect when released to the atmosphere. The pollutants that are most-targeted by this solution are bolded.
CO₂,
F-gas
Trade-offs
Bio-based insulation materials including cellulose often have lower thermal resistance than some conventional insulation materials. In particular, bio-based materials may require a thicker layer than plastic insulation to reach the same insulating performance (Esau et al., 2021; Rabbat et al., 2022). Usable floor area within a building would need to be sacrificed to accommodate thicker insulation, which would potentially depreciate the structure or impact the aesthetic value (Jelle, 2011). This would be a more significant trade-off for retrofit construction and buildings in densely developed urban areas.
Sourcing bio-based materials has environmental trade-offs that come from cultivating biomass, such as increased land use, fertilizer production, and pesticide application (Schulte et al., 2021). Using waste or recycled materials could minimize these impacts. Binders and flame-retardants may also be required in the final product, leading to more processing and material use (Sustainable Traditional Buildings Alliance, 2024).
left_text_column_width
Geographic Guidance Introduction
The effectiveness of deploying alternative insulation is not inherently dependent on geographic factors since it addresses emissions embodied in the manufacture and deployment of insulation materials. However, due to a lack of related data, we assumed a consistent global breakdown of currently used insulation materials when in reality, the exact mix of insulation currently used in different geographic locations will affect the emissions impact of switching to alternative materials.
Building insulation is used in higher quantities in cold or hot climates, so deploying alternative insulation is more likely to be relevant and adopted in such climates. Other geographic factors also impact adoption: Areas with higher rates of new construction will be better able to design for cellulose or other alternative insulation materials, and drier climates will face a lower risk of mold growth on these materials. Local building codes, including fire codes, can also affect the adoption of alternative materials.
There are no maps for the Alternative Insulation solution. It is intended to address emissions embodied in the manufacture and deployment of insulation materials and has no intrinsic dependence on geographic factors.
Advocate for financial incentives, improved building and fire codes, and educational programs for alternative insulation.
Conduct research to improve alternative insulation materials’ 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 of alternative insulation.
Create, join, or administer green building certification schemes and/or public-private partnerships that offer information, training, and general support for alternative insulation.
Further information:
Biomass. Building Materials and the Climate (2022)
Finance only new construction and retrofits that utilize alternative insulation and other low-carbon practices.
Offer grants for developers utilizing alternative insulation and other climate-friendly practices.
Create financing programs for private construction in low-income or under-resourced communities.
Create new contractual terms that require embodied emissions data from materials and methods.
Advocate for financial incentives, improved building and fire codes, and educational programs for alternative insulation.
Fund research to improve alternative insulation materials’ 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 of alternative insulation.
Create or join green building certification schemes and/or public-private partnerships that offer information, training, and general support for alternative insulation.
Further information:
Biomass. Building Materials and the Climate (2022)
Finance or develop only new construction and retrofits that utilize alternative insulation and other low-carbon practices.
Take advantage of financial incentives such as subsidies, tax credits, and grants for installing alternative insulation.
Whenever possible, install insulation that does not use F-gas blowing agents.
Advocate for financial incentives, improved building and fire codes, and educational programs for alternative insulation.
Conduct local research to improve alternative insulation materials’ manufacturing, adoption, supply chain access, and circularity.
Organize local “green home tours” and open houses to showcase climate-friendly builds and foster demand by highlighting cost savings and environmental benefits of alternative insulation.
Create or join green building certification schemes, green building councils, and/or public-private partnerships that offer information, training, and general support for alternative insulation.
Capture community feedback and share it with local policymakers to address barriers such as permitting logistics or upfront costs, helping to share policies that drive adoption.
Further information:
Biomass. Building Materials and the Climate (2022)
Consensus of effectiveness in reducing building sector emissions: Mixed
There is scientific consensus that using building insulation with lower embodied emissions will reduce GHG emissions, but expert opinions about the magnitude of possible emissions reductions as well as the accuracy of determining these reductions are mixed.
Biswas et al. (2016) determined that, for insulation, avoided emissions from reduced heating and cooling energy tend to outweigh the embodied emissions. However, others emphasize that as buildings become more energy-efficient, material embodied emissions become a larger factor in their carbon footprint(Cabeza et al., 2021; Grazieschi et al., 2021). Embodied emissions from insulation can be substantial: Esau et al. (2021) analyzed a mixed-use multifamily building and found that selecting low-embodied-carbon insulation could reduce building embodied emissions by 16% at no cost premium.
Multiple studies have found that some sustainable insulation materials have lower manufacturing emissions than traditional insulation materials (Asdrubali et al., 2015; Füchsl et al., 2022; Kumar et al., 2020; Schiavoni et al., 2016). However, researchers have highlighted the difficulty in evaluating environmental performance of different insulation materials (Cabeza et al., 2021; Grazieschi et al., 2021). Gelowitz and McArthur (2017) found that construction product Environmental Product Declarations contain many errors and discrepancies due to self-contradictory or missing data. Füschl et al. (2022) conducted a meta-analysis and cautioned that “it does not appear that a definitive ranking [of insulation materials] can be drawn from the literature.” In our analysis, we attempt to compare climate impact between materials but acknowledge that this can come from flawed and inconsistent data.
Despite the difficulties in comparing materials, there is high consensus that cellulose is a strong low-emissions insulation option due to its low embodied carbon, high recycled content, and good thermal insulating performance (Wilson, 2021).
The results presented in this document summarize findings from four reviews and meta-analyses, 14 original studies, three reports, 27 Environmental Product Declarations, and two commercial websites reflecting current evidence from eight countries as well as data representing global, North American, or European insulation materials. We recognize this limited geographic scope creates bias, and hope this work inspires research and data sharing on this topic in underrepresented regions.
