Local Cohousing Group is Going Green

“How can we not do this?”

SCOTT DONOVON − Kawartha Commons is a cohousing group developed in the city of Peterborough. We aspire to build a 30+ multi-family, custom designed, residential building; a collection of independent dwelling units that maximize sharing of common resources and reinforces community life through common meals and social interaction by design. My co-housing community is committed to building to a green standard. What does that mean today? Where do we begin?

“Job One” of my Sustainable Committee’s mandate to the membership was to develop and share that vision based on today’s best practices under the umbrella of decarbonizing the economy. It means lessening, then eliminating, our reliance on fossil fuels and other CO2 emissions − a main objective of the Paris Accord and federal government policy of net zero by 2030. This is the pressure you may be feeling these days with media messaging to reduce your carbon footprint.

This same message and call to action impact the building design and construction industry, where I have spent my career. While there’s been a voice for sustainable design for decades, an alignment of goals and targets toward decarbonization has emerged over the past five years.

My career dates to the Arab Oil Embargo of the late 70’s to early 80’s and the emergent consensus to develop energy conservation technologies. But since the 90’s, global warming became the touchstone; yet it has taken more than two decades to regain that focus I think we have now.

Building construction begs our attention because globally it comprises more than 35% of carbon emissions!

The path to net zero or decarbonization can be expressed in simple terms as a Trifecta: energy conservation, carbon accounting and electrification.

Energy conservation

This is an old lesson learned long before the Arab Oil Embargo: don’t waste things, especially energy. Fossil fuels are valuable, limited and increasingly costly. For our cohousing new build, we want to ensure the building consumes as little lifetime energy as possible. Simply put, we will build our house in the same way we dress for a Canadian winter: bulk up with apparel to stay warm. It’s all about the envelope; that is, the sum of all exterior surfaces (walls, ceilings, and roofs). Passive House standards’ 5 guiding principles provide direction.

  1. make the envelope airtight,
  2. add more and better insulation,
  3. use triple glazed windows,
  4. eliminate thermal bridges, and
  5. install ventilation equipment for a reliable, efficient supply of fresh air. The construction cost upcharge for this level of quality comes with a pay-back across time in reduced energy costs.

Our aim is to follow this global standard to keep our operating costs low for the long term.

Carbon accounting

The Passive House standard applies only after move-in because it’s solely focused on operating energy. What about the carbon or CO2 content of all the products and building materials that go into making the house? Your favourite apple pie is not just the pleasure you get from eating it. Its value comes in the quality of ingredients you put into it.

We will carefully select building materials because some carry a heavier carbon footprint than others – concrete, steel, and glass, for example, run high, while plant-based materials, namely wood and straw, are light in carbon. We also understand the full life cycle of building materials by assessing carbon content from mining and processing to construction and demolition.

Carbon accounting for building materials has an analogy in our food marketplace. The 100-Mile Diet has been around for years, and many of us are aware of organic food and buying fresh from the farmer’s market. These things are connected. Pay attention to what goes into the body by looking carefully at where it comes from.

Electrification

Number three of the Trifecta: remove fossil fuel appliances. This is non-technical and one addressed in our personal choices e.g. choosing a gas over an electric stove. It also means employing electrically-driven, high efficiency heat pumps for space heating over gas furnaces and boilers.

Ontario’s electrical grid is mostly clean [see Editor’s note below], so it makes sense to shift our appliances from natural gas to electricity. Gas is still cheaper than electricity, but that will change in time with carbon taxes and other economic pressures. We will build our house for the long term.

This is work only because it requires change. We persistently resist change, yet we have always overcome discomfort because we’re good at figuring out how to make our lives better in the long run.

These three items − the Trifecta − are current, simple, have industry alignment and come with a slight upcharge which, in most cases, enjoys a pay-back. We are not interested in testing new products or pioneering new techniques. Everything is there for us, and it’s largely based on the values of generations before us who lived in a world less obsessed with cheap oil and plastics.

With all that we know and learn, and our awareness of the climate crisis all around us, how can we not do this?

Scott Donovan is a co-housing advocate and co-founder of Kawartha Commons. He works as an architect at Lett in Peterborough ON.

Editors’ Note: There is debate about nuclear energy being ‘clean’ or ‘green.’ The Greenzine will address this issue separately in a subsequent article(s).

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