PORTLAND — A new report says Maine families could save $2,200 a year on their energy bills if the buildings throughout the state were more energy-efficient.

The report by Environment Maine, “Building Better: How High-Efficiency Buildings Will Save Money and Reduce Global Warming,” says widespread use of the latest technologies would increase energy efficiency by up to 30 percent in existing buildings by 2030. It says vast amounts of energy are wasted due to poor construction, inadequate insulation and inefficient heating and cooling systems.

The report calls for improved building codes so that new buildings are increasingly efficient, investment in energy retrofits and weatherization, and innovative financing to spur energy-efficiency investments.