Brookfield Residential’s Midtown Residence Eight in Denver, is the first Colorado home to receive the Passive House Institute U.S. (PHIUS) certification. It is also the first house made by a US production builder to receive this certification. The home was designed by KGA Studio Architects.
To achieve the Passive House certification, the home has a super-insulated exterior envelope. The framing of the home has a double wall construction, with a 2×6 exterior wall and a 2×4 framed interior wall. The exterior wall is flashed with 2 1/2” of closed cell spray polyurethane foam and dense- packed with netted and blown fiberglass fill. The insulation values are R-51 for the walls of the house and R-47.5 for the basement walls. The slab rating is R-20.
The designers tried to make the layout of the home as traditional as possible, so as to make the home feel familiar despite it being a Passive House. A classic master bedroom is located over the garage, while a small portion of insulated roof on the first floor is offset from the walls. In building the home they also had to make sure it complemented the neighboring homes, which have a number of smaller windows all over the façade. The architects had to replicate the look while still keeping the performance numbers high. They opted to place the windows on the west and south sides of the house, thus taking advantage of sunlight and heat. The windows they installed are Alpen High Performance Products 9H and L with an average U-factor of 0.15.
The windows of the home are also inset to the inside face of the exterior 2×6 wall, which creates a “dead-air” pocket that further increases the effective insulation of each window opening. Since the windows are inset, the builders also installed a sloping sill to move “bulk water” to the exterior face of the building. Most of the windows are, however, fixed due to air infiltration concerns.
The home is also fitted with a Navien water heater and boiler, which is capable of learning the usage patterns of the residents and can then anticipate the demand for hot water. For ventilation purposes, the team installed a Zehnder Energy Recovery Ventilator (ERV). The roof is covered with 1.2 kWh of Dow Powerhouse Solar Shingles, which supply the house with the needed energy.
Apart from the PHUIS, the home also received several other certifications, including: U.S. Department of Energy Challenge Home, ENERGY STAR Home, Environmental Protection Agency Indoor airPLUS, and WaterSense.