The annex, adjacent to the original meeting house is a high performing building which shares the same heating system powered by a ground source heat pump. The roof is made using SIP panels with a high R-value and no thermal bridging, while the rest of the walls are filled with soy-based expanding foam.
The new building is completely naturally cooled by upper awning windows, which automatically open at night to allow cool air to flush the space. Those windows also allow ample light into the space, which is supplemented by CFLs and LEDs. The space is also solar heated when the sun shines in the winter, but shaded by overhangs in the summer.