Natalie Leonard, a return speaker at the Passive House Accelerator’s weekly Happy Hour talk, presented this time on the Net-Zero Passive House Sunflower Social Housing Project. Located in Halifax, Nova Scotia, this project is a housing complex intended primarily for underserved populations of women and children. Leonard’s company, Passive Design Solutions, worked with the Affordable Housing Association of Nova Scotia and Adsum for Women and Children to design and create 25 residential units on the site of a former school. Project goals included bright living spaces, offices, and a community center—all designed using a Passive House approach. In addition, the design had to foster feelings of security and community for the residents, so the buildings are set around a central courtyard containing a playground. Funding for the project involved donated land, a $4 million Federal Rapid Housing Initiative grant, an Efficiency Nova Scotia Special Projects rebate, and donations by private backers.
The primary challenge of this project was keeping the costs down in all areas while simultaneously maintaining high-quality net zero design and construction and meeting a strict accelerated timetable for completion—or fast, cheap, and net-zero as Leonard’s presentation was subtitled. In order to meet these objectives, Passive Design Solutions simplified the buildings’ forms and details, working early and closely with a structural engineer to make adjustments. Some of the changes included reducing frost wall thickness from 8 inches to 6 inches, reducing concrete usage by 25%, and avoiding oversized roof trusses. Leonard also made sure to use materials and techniques that were already familiar with the local trades in order to reduce the costs and construction times, while still producing well built and insulated roof and wall assemblies that came in at R89 and R39 respectively.
The project must be completed by March 31st, 2022, so speed of building was and is paramount. Her team worked decisively in getting from initial concept drawings to final construction documents in just six months and was met by a cooperative permit approval process from the city resulting in “unheard of” permit turnaround times. Passive Design Solutions also used panelization, involved the builder in design and pricing options early, and stuck to locally available materials in order to meet their goals. The result is a successful project that looks well on track to deliver new housing to underserved populations of their community by the end of March next year.