Bernhardt Passive Home

Collaboration in design and construction enables the built environment to be comfortable and attractive while also being affordable and sustainable. Exceptional energy efficiency is available without a green premium. Thoughtful design and careful construction can ensure the buildings of tomorrow are vastly better than those of the past. These are the tenets of the partners of the Bernhardt Passive Home.

This certified Passive House is a two-family residence for a young family of four, with active grandparents in a suite. As the front of the lot faces west, the building must maintain a suitable presence from the street while maximizing the southern orientation for solar heat gain in the winter. To provide separation of living spaces for two families on the sloping lot, the upper suite uses the front yard as outdoor space. The lot is on a quiet street and the yard can be landscaped for privacy. The secondary suite on the lower level is on grade, with the backyard as its outdoor living space.

Compared to most passive house designs, this project has a relatively complex form due to the lot shape & orientation, the program and zoning requirements.  The complexity of the building form arises from the “T” shape, an enclosed garage outside the thermal envelope and a couple of other features incorporated to meet zoning requirements. The building meets the Passive House energy efficiency standard with increased insulation levels and some incremental construction costs.

With the exception of a few basic elements, construction costs are identical for passive house and conventional construction.  The elements that differ are design, insulation, framing, doors & windows and mechanical.  More design is required, more insulation, better windows and doors, and slightly more wood framing is used.  The mechanical costs are, however, significantly less.  To replicate the thermal comfort of a passive house, high quality radiant heating (usually hot water) is required in the floors and under windows.  An HRV is still required to ensure air quality, although a less efficient model is adequate for conventional construction. Passive design remains slightly more expensive than conventional, but is more affordable because of reduced operating costs. If the incremental construction cost is amortized with a mortgage, the energy and maintenance savings make the residence immediately cheaper to live in, without waiting for a payback period.

Photo credit for all images: Derek Ford

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