It’s difficult to nail down exactly what Sustainable Spaces does, because the San Francisco company seemingly has its fingers in every aspect of home construction and retrofitting. The company does everything from testing for leaks and dangerous gases, to replacing lighting with more efficient bulbs, to installing solar panels.

According to the company, it has worked on 400 homes since 2004, somewhat fewer than other local companies that work to make homes more energy efficient. However, this is its first round of venture funding.

Rockport Capital Partners and Shasta Ventures led the $6 million investment.