The theme for Architectural Record’s compilation of its 2008 Record Houses was sustainability, and the magazine stuck with green for its web-only Unbuilt Houses feature that was released earlier this week. One local project made the list- the Swell House in Highland Park, New Jersey, designed by New York City-based Studio ST Architects and Z-A. The $400,000 addition will raise the total square footage of the house from an original 900 square feet to 1900, though it’s unclear how far along, if at all, construction has proceeded. The design concept for the home stresses the intersection- and indeed mutation- of old and new living space while acknowledging the site’s local topography, which is just to the east of New Brunswick. A major thrust of the Swell House is the architects’ investigation of "the properties of the most mundane suburban cladding material- the clapboard," which is used in a variety of functional ways.