Construction costs for developer Postgreen’s flagship project, the 100K House, came in at just under $100,000. The 1,150 sq. ft. home is aiming for LEED Platinum certification

How inexpensive can urban green building get? There are a bunch of builders, architects, and developers out there trying to figure that out. One of them, a Philadelphia-based developer called Postgreen, took a shot at building a 1,150 sq. ft. townhouse in that city for just under $100,000 in construction costs.

The result is called, appropriately, 100K House, and a blog about the project indicates construction is complete and the site is ready for landscaping.

Postgreen’s president, Chad Ludeman, and its marketing chief, Nic Darling, set up a website on which they regularly blog about the progress of their projects, which also include two homes, at about 1,300 sq. ft. each, that will be built to Passivhaus standards (both are already sold but not yet completed), and a home called the 120K House, a 1,270 sq. ft. townhouse that, like the 100K House, is in Philly’s East Kensington neighborhood and designed for LEED Platinum certification. The 120K House, whose construction costs came in at about $120,000, was purchased in April for $275,000 and is now occupied by its owners.

Postgreen also says it has another, three-house project in the planning stages.

The developer used the services of Interface Studio Architects, builder Manor Hill Contracting, and green building consultants MaGrann Associates, among others.

Ludeman and Darling say one of the principal motivations for doing the 100K House—which features SIP insulation, an energy recovery ventilator, radiant floor heating, low- or no-VOC finishes, and solar thermal hot water—was to “prove that green construction can be affordable if properly designed and executed.”

Check out the Postgreen blog, at http://www.100khouse.com/ , for project updates, most of which are written, with glib candor, by Darling.