Most of the buzz surrounding Passive House seems to be related to energy efficiency. On the one hand, you’ve probably heard about the 90% reduction of energy use, no furnace, net zero ready. While, on the other hand, we hear that “green buildings” often fall short on the energy efficiency expectations. What is it, then?
In this post we asked our principal, Oscar Flechas, to address common misconceptions of what Passive House can and can’t do.
1. A Passive House building will cost you an arm and a leg:
As with anything in the construction world, it really comes down to the type of project and the complexity of the design. Compared to standard construction, on average, Passive House costs only 10-15% more — your arms and legs are certainly worth more than this!
This extra cost is often due to four reasons:
a) The limited availability in Canada of certified windows and doors that will ensure air tightness, although soon this won’t be a problem. As the market for Passive House has expanded in the last decade, Canadian manufacturers — such as EuroLine — are catching up and helping bring down component costs for our clients.
b) Depending on the climate, insulation material requirements can be much higher than the requirements of the Alberta Building Code.
c) High-quality materials that surpass code minimums are pricier.
Nevertheless, despite these higher up-front costs, the long term benefits are extraordinary. The quality of the building components helps bring down maintenance costs, energy efficiency translates into lower energy bills, and the exceptional air quality of Passive House buildings improves health and productivity.
For all these reasons, after comparing the construction and operational costs of a conventional building vs. Passive House, the Town of Valleyview decided to build their new town hall to the Passive House standard, and called for a design-build team knowledgeable on Passive House: Scott Builders, Flechas Architecture, Marken Consulting, Integral Group and Laviolette Engineering Ltd.
Not to mention that the popularity of Passive House for affordable housingdevelopments is quickly rising in Canada.
Valleyview Town Hall, April 2018. (Credit: Oscar Flechas)
2. Passive House buildings won’t perform in extreme climates:
It depends. It certainly is more difficult — and costlier — to achieve Passive House certification in extreme climates, but not impossible. If you take into account that most of the energy buildings consume is used for heating, lighting and cooling, any step towards energy efficiency is a good step. So even if a building designed to meet the Passive House standard doesn’t achieve certification, it will be as efficient as it can get for its context.
Some of the northernmost certified Passive House buildings are located in the nordic countries where, despite having milder temperatures than the northernmost regions in Canada, long, dark winters are the norm. Somewhat similar to the climate patterns observed in most Canadian urban areas.
An example of the feasibility of the standard in a harsh climate is the Valleyview Town Hall. We designed the this building to remain at a steady indoor temperature of ~20°C, while outdoor temperatures can dip to -40°C in the winter, and rise to +35°C in the summer.
3. 90% lower energy bills:
This is a bit of a myth, 90% originally refers to the energy use reduction for space heating and cooling under optimal conditions, in the 1990s. Recent research has shown that, compared to a standard building, Passive House can reduce space heating demand by 80%, for example. In the case of the Valleyview Town Hall, operational use aims to reduce energy consumption to 1/8 of the average energy used by public administration buildings in Canada.
4. Passive House buildings use more energy than Net Zero:
Net Zero only refers to a building that produces as much energy as it uses, this does not necessarily equal energy-efficiency. Although Passive House certification doesn’t require energy production, our buildings are “net Zero ready”. That is, the low energy consumption of a Passive House building makes it much easier (and cheaper) to produce the necessary energy on-site or go entirely off-grid.
Ultimately, the Passive House Standard provides the basis for the most resilient buildings possible. In the face of a changing climate, resiliency is architecture’s next big challenge.