Inside is where most people are most of the time. As central features of human life, buildings furnish space in which to dwell, gather, labor, trade, make, learn, heal, and revel. Of all the things we create, buildings are the largest, and they generally persist for decades, if not centuries. Already the world has more than 230 billion square meters of building space. Another 65 billion square meters could be added this decade.
It’s no surprise that buildings are major drivers of emissions. Some stem from the materials that comprise buildings and the process of construction, renovation, or demolition—what’s known as “embodied carbon.” Many more emissions are the result of ongoing use. Fuels are burned on site, primarily to heat space or water or for cooking. The chemicals used for cooling and refrigeration can escape as emissions. Through these direct, on-site sources buildings produce 6% of heat-trapping emissions worldwide. Buildings also use more than half of all electricity, creating an off-site, upstream impact on electricity-generation emissions (as explored above).
How can we retrofit existing buildings and create new buildings to minimize energy use? How can we stop other, on-site sources of emissions? These questions are at the heart of making buildings not only better for the planet, but also more affordable to operate and healthier, better places for the people inside and around them. Building solutions orient around energy efficiency, energy sources, and refrigerants.
- Enhance Efficiency. Whether for building retrofits or brand new construction, energy-efficiency solutions are largely the same. Many address the building “envelope” and insulation—means of keeping conditioned air in and unconditioned air out—while others use technology to optimize energy use.
- Shift Energy Sources. Clean alternatives can replace more polluting fossil energy sources typically used to heat space, warm water, or prepare meals.
- Address Refrigerants. The gases used as refrigerants today are potent greenhouse gases. We can reduce emissions by managing leaks that often happen within buildings, as well as properly disposing of refrigerants (a waste process that falls under industry, above). Ultimately, these fluorinated gases can be replaced with alternatives that are not greenhouse gases.
Many building solutions reduce on-site emissions and enhance electricity efficiency, reducing emissions at the power plant. Taken together, these solutions can transition buildings from being a major problem to potentially net-positive, as the “greenest” buildings can produce more energy than they consume. These solutions can also help ease the “energy burden” many low-income households face, as energy bills often consume a significant and disproportionate percentage of income.