A 1960s home has been reborn into an eco-friendly abode with an impressive net-zero energy footprint. Designed by local architecture firm Neumann Monson, the Koser II is a single-family home that combines forward-thinking sustainable strategies within a contemporary envelope in a leafy and walkable Iowa City neighborhood. Powered by solar and geothermal energy, the home doesn’t sacrifice comfort or luxury in its pursuit of energy efficiency — it even includes a beautiful backyard pool.
Covering an area of 2,850 square feet (including a 420-square-foot finished basement), the Koser II house is mainly spread out over a single level. To provide privacy, the street-facing facade is primarily clad in dark cedar planks and punctuated with few windows. A long slatted timber screen near the entrance also shields the home from views and frames an outdoor dining area. In contrast to its introverted exterior, the home’s interior is bright and airy with full-height glazing that lets in plenty of natural light and views.
“The design bears the mark of the 1960s home that came before it,” the architecture firm explained. “Removing the existing house’s superstructure and incorporating its slab-on-grade foundation into the new construction makes the most of the predecessor’s limited potential. Additional foundations and a concrete collar support exterior walls of nine- and 10-foot pre-cut studs. Their height differential provides adequate slope to the 14-inch truss-joists spanning the 20-foot width. Operable windows extend to the ceiling plane, maximizing daylight penetration and encouraging cross-ventilation.”
The renovated home also features foamed-in-place insulation and a continuous rigid insulation shell with R-24 walls and an R-40 roof. The light-filled interior is supplemented by LEDs at night and equipped with EnergyStar appliances. Radiant floor heating is complemented with a geothermal climate control system connected to an underground horizontally bored loop. A rain garden in the backyard mitigates stormwater runoff, while a 10.08kW solar array brings the home to zero-energy building performance.
Images by Cameron Campbell Integrated Studio