Scrolling down on my screen, looking at new apartment buildings built to meet Passive House standards, I am constantly checking to make sure I am not getting the construction dates wrong. Their resemblance to slab towers of the 1960s, with minimal articulation, small and repetitive windows, no balconies and only some spots of paint here and there make it seems like design was pushed to the bottom of the priorities list.
Almost 70% of the world’s population will be living in dense urban areas by 2050, and I know that considering the climate emergency we are in, it is crucial to implement standards to help us build high-performance multi-unit buildings in our cities. But the way we are designing today to meet these standards makes me wonder: where are we heading exactly? To greener but uglier cities? Are we (architects) being lazy?
First, what is Passive House and how is the City of Toronto making it the new standard?
Passive House is both an approach and a building standard. It is currently the most rigorous energy-based standard in our design and construction industry.
The passive house approach is to minimize the heating and cooling loads through measures such as specific massing requirements, insulation, elimination of thermal bridges, and so on. As rigorous as these measures are, they are still considered “voluntary” in the Toronto Green Standards system. So, why am I concerned?
Accounting for 58% of Toronto’s total Greenhouse Gas (GHG) emissions, the building sector has been, and continues to be, the primary source of GHG community-wide emissions. That is why the City set the ambitious target of zero-emissions development by 2040. A target that required a market transformation strategy.
As part of this strategy, in 2006 the City introduced the Toronto Green Standards (TGS). It was first a voluntary standard and later, in 2010, it became structured into two tiers of performance, with Tier 1 being mandatory and Tier 2 being voluntary with financial incentives (development charges rebate). Since then, a new updated version of TGS comes into effect every four years. Each version raises the bar one step higher.
This means that, for example, the voluntary tier 2 of 2018 became the mandatory tier 1 in 2022, and, consequently, the highest standards of currently voluntary tier 4 (almost equivalent to passive house standards) will become mandatory for all new developments in 2030.
The most recent version of TGS, V4, came into effect as of May 1, 2022. It is a comprehensive set of guidelines, consisting of four tiers. Each has specific goals to improve air and water quality, manage stormwater onsite, enhance the urban forest and biodiversity and provide energy-efficient buildings.
When it comes to the eligibility requirements for the highest tiers, along with CaGBC Zero Carbon Building Standard, Passive House Standards is an alternative compliant option that will be accepted for tier 3 or tier 4 applications, and as indicated in 2021 technical report of TransformTO Net Zero Strategy, the target is to scale Passive House up to 100% by 2040.
Second, how these standards “can” turn our architecture into big bulky boxes
Even though Toronto has a clean electric grid, some fossil fuel sources are still being used in operational phases of our buildings. In addition to that, despite fuel switches to electrical systems at higher tiers of TGS, excessive reliance on heating and cooling systems, especially during peak energy demand, can still put a great pressure on the energy grid and lead to increased use of non-clean energy sources and GHG emissions.
Therefore, increasing buildings' resilience and minimizing the reliance on energy-intensive HVAC systems is one of the key targets of TGS. In tier 4 design guidelines, it greatly focuses on the efficiency of building envelopes to lower GHG emissions associated with power generation. This is where tier 4 requirements get very close to Passive House Standards.
Minimizing the thermal bridges is a big deal when it comes to improving envelope efficiency. In the building envelope, thermal bridging can potentially occur in areas such as walls, balcony slabs, cladding attachments, window wall slab by-pass and slab connection details.
To reduce the building’s energy loads and thermal bridging, tier 4 requires measures such as creating airtightness, maximizing lighting power densities, reducing window-wall ratio, using materials with higher R-values in windows, walls, and roofs, and prioritizing compact massing and form in building design, which usually translates to smaller windows, smaller balconies (or, more commonly, no balconies at all), and no articulation to the built form.
This is exactly the critical point I am talking about. The point where the way we decide to incorporate these guidelines into our design defines the future of design.
There is no doubt that improving building envelope efficiency is very important and should be taken seriously. But there are advanced technologies and innovative design strategies that enable us to do so, while creating beautiful buildings that can add to the diversity of our urban environment instead of denying it.
Over the past 50 years, we have come a long way to create cityscapes that are more interesting, exciting, playful, and vibrant, and focus on the pedestrian experience. Now is certainly not the time to stop doing so. We cannot risk creating a future that is very similar to the past we have fought so hard to change.
We don’t necessarily have to design repetitive small windows, and uniform, boring boxes with no balconies to create energy-efficient buildings. There are many strategies we can implement to minimize thermal bridges. Strategies such as utilizing thermal break systems, designing insulated balcony slabs, employing careful detailing and construction to avoid direct contact, or using high-performance materials to reduce the thermal bridging effect.
These strategies might be a bit more expensive or time-consuming to integrate into design, but in return, we don’t have to wake up one day and see we have created soulless cities that no one likes to live in, unattractive streets that no one wants to walk in, and uniform buildings that no one wants to look at.
Third, in a city where we argue about giving up the backyard, can we really give up on balconies?
Aside from the aesthetic points, I want to make another more subtle and slightly politicized point about eliminating balconies in multi-unit buildings.
Toronto is changing constantly and rapidly, but we must admit that in the middle of a housing crisis we are still getting push back from those who think the sun won’t rise on their houses (pun intended) if a multi-unit building is built in their neighbourhood.
I have always been outspoken, opposing the mindset that values people’s private backyard over new housing for dozens of young families struggling to find a place to live in this city. However, I cannot ignore the fact that having a private outdoor space, like a balcony, is what many people living in dense urban neighborhoods would cherish.
Eliminating balconies to achieve high efficiency building standards could be a step too far. I very much enjoy hanging out on the shared roof terrace of our building, in the same way I prefer my neighbourhood parks over a backyard any time of the day. But I also believe that no matter what we prefer, what is crucial is having a choice. It is our duty to give people options to choose from. Of course, I am not talking about putting balconies everywhere or when it is not practically justified, but that should be a matter of design.
At the end of the day, we are designers, and that is what we should do; design
