The Heights

The Heights is a six-story, mixed use building located in a rapidly developing area in Vancouver’s northeast. The ground-level commercial space and single level of underground parking are constructed in concrete, with 85 apartments occupying the rear of the ground floor and five stories of wood frame construction above.

At the time of construction, The Heights was Canada’s largest building designed to the Passive House (PH) Standard, an internationally recognized standard for achieving very low energy use in buildings (80 to 90 per cent less energy for heating and cooling than conventional buildings). The decision to build to PH Standard was made during the rezoning process. The site was rezoned under the City of Vancouver’s Rental 100 program, which offers developers density incentives to construct purpose-built and covenanted rental housing. According to city policy, rezoned projects are required to meet high environmental standards.

The principal strategies for achieving PH Standard are based on a high-performance building envelope and continuous managed ventilation. The necessary components of the building envelope include high insulation values with minimal thermal bridging, air tightness, and managing solar gain (admitting during the heating season and reducing during the cooling season). The benefits include minimized energy use, improved user comfort and high indoor air quality, all in a relatively simple building with low operating costs.

Wood frame construction is ideal for achieving PH Standard buildings. Wood itself has a reasonable insulation value and facilitates detailing to minimize thermal bridging. During design development, different wall assemblies were considered, with attention to the position of the insulation and air barrier layers. An assembly was selected based on constructing the load-bearing structure conventionally and a second service wall installed internally, with a rigid insulation panel between providing continuous insulation and a protected air barrier. Installing a membrane to transition the air barrier around the outside of the rim joists at the floor lines was the only specialized PH intervention during rough framing. Among the key reasons for adopting this approach was the complexity presented by the zero-lot line condition on the east face and the advantages for ease of attaching appendages such as sunshades and guards. The decision was also made to insulate above the parkade slab to reduce thermal bridging, rather than the more conventional approach of applying spray insulation to the underside.

Construction was completed at the end of 2017. At the commissioning stage, the airtightness test showed only 0.3 air changes per hour, half the air infiltration rate permitted by the PH standard. The building will be monitored over its first two years of operation.