Sustainable Spaces bills itself as a company performing home energy retrofits and in the past year and a half it has become one of the more visible California companies in the market.

But its ultimate goal is to become a software company. That's crazy talk, you say. This picture is your proof. That's founder Matt Golden standing in front of one of the many white boards throughout the company's office that seek to create decision trees for the astounding number of variables one might find in a home. Do any of the residents have asthma? If yes, does the house have air conditioning? If yes...

"Every week we release new software," Golden said. "We're standardizing the data gathering."

Ideally, the software will allow a carpenter or customer service representative to add observations and data from a customer's home into a computer and get out a retrofit plan, or a few plans based on the amount of money a customer wants to spend. 90,000 energy retrofits will take place in California in the next two years and the state will spend $3.1 billion for energy efficiency from 2010 to 2012. The software, hopefully, will eliminate human error and/or shortsightedness. Retrofits will likely be a big topic at West Coast Green, which starts this Thursday at Fort Mason.

Although it now conducts retrofits itself, expect to see Sustainable license this. Some of the company's new employees hail from Google.

The white board above tries to guide a carpenter or customer service agent through all of the variables when it comes to home heating. Do they have radial heating? If so, does it work? Is it efficient? Walls in some rooms are festooned with chains of Post-It notes containing hurried handwriting. It sort of looks like something left by a team of academics or a political prisoner stranded in solitary.

And the world's largest home utility bill? One Sustainable customer was experiencing $6,500 monthly bills. Something about a water slide.

If you want to see how retrofits work, check out this fine documentary of an assessment of my waterslide-less home.