Natalie Leonard, P.Eng., brings passive homes into the mainstream
By Peter Saunders
While stricter buildings codes, government incentives and environmental concerns are all making ‘green building’ a hot topic today, Halifax-based Natalie Leonard, P.Eng., became Canada’s first certified Passive House (PH) consultant and builder 10 years ago. Since then, her company—Passive Design Solutions—has completed more than 100 projects that are net-zero-ready. Along the way, she has focused on making such homes more easily affordable for the mainstream market.
With that in mind, we recently spoke to Natalie about how her background as a civil engineer helped turn this international concept into a local reality.
How did you get into engineering in the first place?
My dad and my brother were civil engineers. Math and physics came relatively easily to me in school, so the field seemed like the right choice at the time.
However, when I graduated with my degree in 1984, there weren’t a lot of openings in the industry. My only job offer came from the forestry industry, where I had no interest. So instead, I worked with my dad in general contracting for a few years, about half residential and half commercial.
It turned out I really liked residential construction. There was a lot of opportunity to be creative.
While studying at the University of Toronto (U of T), I worked as a project manager for a big residential builder, but they were too money-oriented and took shortcuts. I ended up moving away from construction, serving as a project manager in health-care technology—but as I never really had a passion for health care, I always kind of kept one toe in construction.
What drew you to green construction?
When I got the chance to travel in Asia, I saw how much simpler and less wasteful their construction methods were than ours back in Canada. That experience cemented my environmentalism.
Later, as I was addressing energy efficiency for one of my projects, I learned about the PH standard, which ensures a building requires very little energy for heating and cooling, making conventional furnaces and air-conditioning systems obsolete. This appealed to me in both environmentalist and practical terms.
I booked my airfare to Chicago to attend a first round of training in 2008. I finished my certification in 2009.
At first I did all of that out of personal interest, but then I decided to become a consultant and registered my own company. I built a ‘spec’ house in Halifax, sold it at list price and got things rolling from there. I started six houses in rapid succession.
My company grew into a team of professionals. At first, we did design-build, combining design, energy consulting and construction. Then we would just build the ‘shell’ of a house and other builders would fill in the details. Today, we are focused completely on the design work. We are small and extremely specialized.
I am also licensed to teach a PH builders’ program in both Canada and the U.S. While the fundamentals of energy efficiency have been well-understood since 1990 or so, the PH standard takes construction to the extreme, to the point where you do not need a central furnace.
How do you address your clients’ needs?
About half of our clients want a custom design, while the other half—ranging from young families to retirees—use the stock plans we have developed over the years.
Those seeking custom design that incorporates energy efficiency from the start of the process are not so much concerned about reducing their energy bills, as they can afford to pay those, as they are about doing what’s right for the planet. These designs are often site-driven, i.e. based on the grade of the landscape, where the doors need to be, etc.
For those who buy our stock plans, on the other hand, the main motivation is energy security. They want to control their home’s operational costs.
This is a significant issue in Nova Scotia. Many older houses here are still heated by oil, their insurance rates are increasing and we only have limited access to natural gas. Meanwhile, Nova Scotia Power’s electrical rates, already the highest in the country, are predicted to double or triple in the next 10 years.
Thankfully, with careful design, a provincial rebate program means we can build a passive house at the same cost to the buyer as a traditional house.
There are other benefits, too. Compared to older houses that experience massive air leakages and are always cold, a passive house’s building envelope is comfortable and resilient during storms, with no risk of freezing during a power outage.
In summer, the envelope helps keep the heat out, but we can also use heat pumps as small-point sources for cooling. Most of our clients use no to very little air-conditioning.
In fact, we track our houses’ energy consumption over the first year and compare it to a PH model. Our clients are only spending $700 to $1,000 annually on their energy bills. Many are going net-zero by adding solar panels. Some are taking their houses off the grid.
One of the best ways to help the environment and save money is to build the smallest house you can live in, but the irony is it is very difficult for a really tiny house—let’s say, 500 square feet, with one bedroom—to meet the PH standard, since it has a very large surface area in relation to the amount of living space.
Where do you see the PH standard heading in Canada?
There’s now a regional ‘culture’ of passive houses in both Nova Scotia and British Columbia, but to move the standard further into the mainstream, we need to be able to provide designs using locally available materials, with local support.
We also want to use more locally manufactured products, rather than import German-manufactured windows, air-sealing tapes and membranes, so we can save money and access them more readily. Canada should do better with heat recovery ventilators (HRVs), for example, some of which are being manufactured in Quebec but only sold in Europe! This is the market reality today because the National Building Code of Canada (NBC) does not dictate the efficiency of HRVs, but since municipal and provincial codes can be overlaid on the NBC, there are local opportunities to make PH more mainstream.
My background is mainly single-family residential, but we have also provided consulting for commercial offices and an apartment building. At that larger scale, the building envelope becomes less important, while the mechanical design becomes more important.
So, for that market, mechanical engineers should be the ones doing the energy modelling. Some of the younger ones I’ve met are aware of that opportunity.
This has all helped guide my decision to focus on bringing the PH standard to the mainstream residential market in Canada and the Northeastern U.S. Our client enquiries are increasing dramatically in response to public awareness about the climate crisis. After all, building a new home may be the biggest opportunity any individual has to reduce their carbon footprint and help in the fight against climate change.