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In Portland, Oregon, in 2015, an innovative 57-unit affordable housing project was completed. In 2018 a 42-unit affordable housing project was built in a similar way in Ottawa. In Boston it is two phases, one 28 units that’s finished, and one coming soon at 37 units. And in Woodstock, Ontario, 26 units of affordable housing are still under construction and expected to be complete this year. The way these projects relate to each other is that, although different architects and mechanical designers created them, they all employ a similar, relatively new model. And they do not use fossil fuels for HVAC systems.


Affordable housing Passive House projects in Woodstock, Ottawa, Portland and Boston.

The model they have selected is likely to continue to be used all over North America in the next few years. In a nutshell, it’s a Passive House (super-insulated) building envelope, with heat pumps and energy recovery ventilators for space conditioning.

More than a year ago, Toronto Passive House consultant Rob Blakeney wrote: “Other social housing providers in B.C., Alberta, Manitoba and across Ontario are now looking to the Passive House standard for their projects. But Passive House adoption within the Canadian affordable housing community pales in comparison to widespread adoption seen in the US. As of the end of 2017, housing agencies in eleven US states have prioritized Passive House in their applications for affordable housing funding, with twenty-four additional states actively working to develop similar programs.”

“By incorporating Passive House into its scoring criteria for the award of limited federal funding (via a 9% tax credit) available for affordable housing, nearly 40% of the 2015 affordable housing proponents in Pennsylvania applied as Passive House Projects. The construction cost premium calculated between Passive House projects and non-Passive House was less than 2%.”

Among the five projects mentioned at the beginning of this article the largest first cost premium was “6% - 9% more than code built structures.” But this is unusual. Usually it’s less. The description of Distillery North project in Boston states: “While the enhanced thermal envelope and detailing can be costly, this expense is offset by much reduced costs for heating and cooling equipment and associated ductwork. Taking into account a substantial lifetime reduction in operating costs, one can see that any initial cost premium should require a payback of only a few years.” Each unit in the Karen’s Place project in Ottawa costs about $30 per year for heating.

The Passive House approach is also being applied to a 163-unit retrofit of a 1950s building now being planned in Brooklyn, New York.

HRAI members who are working on affordable housing, or indeed, any kind of multi-family development, may do well to take note that this model or a net-zero type of approach is likely to continue to spread. Many cities are phasing in low carbon frameworks that might accelerate the trend. The years 2030 and 2035 seem to be the targets for full implementation in municipalities who have already established policies. It might be time to brush up on your heat pump and ERV case studies!