How the Passivhaus movement found a home in Vancouver
t all started modestly enough with a collection of terraced homes in Darmstadt, Germany. In 1990, a building physicist called Dr Wolfgang Feist started to build a unique dwelling based on the principle that it should require no active internal heating — in German, passivhaus.
It was a radical idea inspired by Dr Feist’s Swedish colleague Bo Adamson who had been working on unheated homes in China which he called ‘passive houses’. In simple terms, a building that was properly insulated and airtight would be warmed by the outside air and by people and appliances inside. There would be no need for furnaces or radiators. As Dr Feist said at the time, the best energy is the energy you don’t use. Today, there are passive house offices, hospitals and homes all over the world (and design professionals in British Columbia are pushing the envelope and creating firsts, like recreation centres such as Clayton Heights Community Centre.)
More than thirty years later, the principles of passivhaus are shaping the thinking of developers like ASPAC, and consultants like Harold Louwerse of Morrison Hershfield, as we prepare for the next great shift in sustainable building. The first step is called Step Code, logically enough!
NET ZERO BY 2032
“The goal is net zero energy by 2032, so we have a 15-year plan essentially to slowly implement Step Code 2,3 and 4. The goal is that we’ll all be doing a net-zero build (Step 5).
“STEP Code was implemented in 2017. It focuses on total energy use and total energy demand. It’s how the building envelope impacts all of that. That corresponds to airtightness. We don’t want to heat or cool the air and have it literally go out the window. That’s a big focus for my group in Vancouver, meeting those targets for Step Code. That’s the biggest challenge for us,” says Louwerse.
Companies like Morrison Hershfield are part of a much bigger team on projects like ASPAC’s River Green. Architects, for example, have a big role to play.“
“You can’t design an exposed concrete high-rise any more. We need to move to exterior insulation, cladding systems, efficient glazing systems with extra insulation. That’s going to be a big push now and in the future.”
Principles of the Passivhaus reduce the need for heat supply from natural gas or electricity
Image credit: Creative Commons, passivehouseaccelerator.com
The highest building to be built to Passive House Standard is the Bolueta in Bilbao, Spain
Photo credit: Varquitectos
BUILDINGS IN OVERCOATS
Essentially new buildings will all be wearing overcoats. The insulation prevents heat loss from inside the building in the winter or heat buildup from outside impacting occupant comfort in the summer. Morrison Hershfield are leaders in modelling the performance of different types of exterior systems to help manufacturers to create more efficient cladding.
In a Step Code building in Vancouver, what will homeowners notice in the next 10 or 15 years?
“Heating bills will be lower. And it’ll be more comfortable indoors — sitting by a window won’t be draughty. Indoor air quality will be much better because we’ll stop exterior pollutants from getting in.
“You’ll probably see less external glass. And you’ll see higher performing glass. There’s a big push right now for heat pumps, and HRVs (heat-recovery ventilators.) There are a lot of changes happening there with mechanical equipment efficiency.
LONGER LIFE BUILDINGS
“I think the embodied carbon in materials is going to be key. We’ll be taking a cradle to grave approach to materials — as we move up the steps to passivhaus. That is the future. What we’re being asked to do is a life cycle analysis: where is it being sourced and produced, is there serious environmental impact during its life, can it be easily disposed of and is it recyclable?
“The environmental impact of the entire building will be assessed. I think the challenge is using a product like wood (mass timber) in a 50-year building instead of steel and concrete. Most wood buildings have a 25-35 year lifespan. If a building can last longer with the same or lower carbon input, then we’re golden.”
ASPAC has already contributed to sustainability in Vancouver by replacing a handful of single-family homes with hundreds of more efficient multi-family homes. The next phase of our sustainability story will be to embrace new technologies and building methods to make step-code compliant towers and move towards the goal of net-zero builds.