“Cool” roofs and even cooler designs dominate a recent list of sustainability solutions put out by the American Institute of Architects. A border entry center powered by the sun with concrete “sponges” to collect rainwater, an apartment complex for the homeless maximizing light and airflow, with a “cooling” rooftop design, and the Etsy HQ retrofitted with renewable energy from its original use to store a printing press are among the projects highlighted. The projects reflect the reach of “low-energy” strategies and the embracement of sustainability in the building industry.

This shift being seen has been heralded by environmental advocates as a crucial revolution, reports The Washington Post. After all, the building industry accounts for 40% of the world’s total carbon emissions, well ahead of transportation.

Two centuries ago the nation began its rapid expansion of building, dramatically increasing CO2 emissions, but it wasn’t until 2005 that building efficiency started gaining traction. Since then, while the industry continues to grow, emissions have dropped 30%. Energy consumption has dropped 5%.

According to Edward Marzia, founder of Architecture 2030, a nonprofit out of Santa Fe, NM, building “green” isn’t a hard sell. Cost effective designs can make high-performance buildings with little to no energy consumption or emissions. And while new construction is an obvious target for low energy design, but the American Institute of Architects also highlights a need to adapt and retrofit existing buildings.

Already there are benchmarks and performance metrics in place helping cities across the country set goals. The 2021 International Energy Conservation Code even set new minimum efficiency standards for a myriad of construction elements.

Cities like Burlington, VT, are certainly paving the way in enforcing these policies and standards. The city was the first in the US to go all-renewable with the opening of a hydroelectric facility back in 2014. A “carbon fee” is also planned to be leveraged on buildings tapping into “the fossil fuel infrastructure.”