ed nortonNorton hit Congress to testify about the value of green building in 2008.globalwarming.house.govA major investment in making affordable housing greener — a $4 billion investment, to be precise — was announced Wednesday. The injection comes courtesy of Enterprise Community Partners, a 25-year-old non-profit dedicated to community development and affordable housing. With heavyweight partners including NRDC, HUD, and the Home Depot Foundation, Enterprise — which was founded by the grandparents of actor Edward Norton, who sits on its board — has set its sights on overhauling the entire affordable housing stock in this country.

Well, in that pebble-in-a-pond sort of way. The actual $4 billion will be split, with $2.5 billion going toward the construction or retrofit of 75,000 units across the country, and $1.5 billion going toward research and systems reform work. Through its work with state and local governments, Enterprise Green Communities hopes to have an eco-influence on hundreds of thousands more units, and leverage lots of dough. If that’s not enough, its leaders are calling for the country’s entire affordable housing stock — around 30 million households — to be green by 2020.

It’s the kind of energetic, solution-y plan that makes you have real hope for a millisecond. Even if the 30 million households vision doesn’t pan out, there’s real progress to be made. As speaker after speaker pointed out in a conference call this morning (in which Norton was supposed to participate, but he wasn’t there, not that it’s the only reason certain people called in, ha ha, but where was he?), this isn’t greening merely for the sake of environmental progress — it has tangible effects on the health and quality of life of residents, as well as holding the potential for green job creation, energy savings, and significant carbon reduction.

In fact, Enterprise has just rolled out the results from its work over the last few years. In conjunction with its splashy announcement today, it released a report called Incremental Cost, Measurable Savings: Enterprise Green Communities Criteria. Not the hottest title, but it gets at the point that green builders and fans of retrofitting try to make day in and day out: choosing greener options doesn’t cost that much more, and it saves a hell of a lot over the long run.