The Carlsson Family Home is a 3,157 square foot home built by Birdsmouth Construction in Portland Oregon. Construction began in July of 2014 and the home was completed in June of 2015. The original home was a 1925 craftsman that had a poor foundation, uninsulated walls, single pane windows, an old gas furnace and a leaky composite shingled roof.
The clients were Swedish and had a goal of a quiet, comfortable, high quality home that would last generations- similar to the homes they had lived in back in Europe. Their goals also included being as energy efficient as possible. Birdsmouth worked with the architect, Ray and Beate Cully of R&B design group to create a home that would meet Earth Advantage Platinum and Net Zero Home certifications.

The home was lifted off of its old foundation and excavated to increase its footprint. A new foundation and slab were poured with 3” exterior EPS foam to the outside of the foundation walls, and 6” of EPS insulation under the slab and footings. The home was placed back down and the original first and second story floor systems were preserved.

All existing 2×4 walls were furred out to 5.5” and new walls were all 2×6 construction. These were sheathed with Zip System sheathing, and the joints and seams were sealed with the Prosoco liquid flash system. To the exterior of the sheathing, Birdsmouth added 2” of cork insulation followed by a fully vented rainscreen assembly and cedar lap siding. The interior wall cavities were filled with 5.5” of dense pack cellulose.

The roof assembly was built from 2×12 rafters, which the wall sheathing went up and over. This allowed for dense pack cellulose in the vaulted ceilings. Over the sheathing, which acted as the primary vapor control layer and the air barrier, 2×6 rafters were installed to create a space for 3.5” of rockwool insulation and a vent space. The tails ran long over the wall plane to create the overhangs for the building. This was then sheathed and a metal roof was installed. Soffit vents and a ridge vent provided for ventilation of these cavities.
Triple pane Zola windows and doors were used, including 3 large lift slide units. The average U value of the windows is U.12. The windows were installed into the rough openings with Hanno Band expanding foam tape.

The final blower door test out was a .5 ACH50. To provide for ventilation and heat recovery a Zehnder Comfo Air HRV was installed and balanced. For heating/cooling a 15,000 BTU Mitsubishi ducted mini split heat pump was employed. Water heat is supplied by an electric tank style water heater. To offset the energy usage, a 7kW solar array will be installed on the garage.