Yesterday, the Boston City Council approved a proposal to adopt stricter energy efficiency regulations for new buildings.

The "stretch code" will require new residential and commercial buildings to achieve approximately 20 percent better energy efficiency than is required by the state’s base energy code, according to a statement.

"Boston has once again shown that our city is on the cutting edge of environmental policy and sustainable development," said Mayor Thomas M. Menino. "The adoption of this new energy code keeps Boston at the forefront of innovation in high performance green buildings while helping save property owners and tenants on utility bills, reducing our carbon footprint and growing the local clean tech economy."