It’s widely known Canada is facing both an affordable housing crisis and a climate crisis, and the worst possible outcome is solving one to punish the other. If we make the wrong choices today, we risk locking in generations of unnecessary emissions, future maintenance and retrofit costs, infrastructure strain, and climate vulnerability.

Much of the current conversation around low-carbon construction focuses on embodied carbon—the emissions associated with manufacturing construction materials and building homes. That’s not an unwelcome development, because embodied carbon matters.

But it’s a serious error to debate the carbon footprint of building materials in revisions to the National Building Code while overlooking the emissions we can save by improving buildings performance. The fastest, most cost-effective way to reduce emissions in buildings is still to reduce the amount of energy they need in the first place.

That potential isn’t reflected in a July, 2025 policy paper by the Canadian Board for Harmonized Construction Codes (CBHCC), published as a contribution to the 2030 Model National Building Code. The CBHCC takes its cue from a tiered approach to operational carbon emissions which was introduced in the 2020 model code. But it focuses entirely on building elements that draw power—like mechanicals, water heaters, and lighting—to the exclusion of materials like insulation that save operational energy and carbon.

The life cycle “carbon payback” from energy efficiency is reinforced by a recent analysis [pdf] for NAIMA Canada by Building Knowledge Canada. It found that, in many cases, the carbon savings from reduced operational energy use far exceed the building’s total embodied carbon over a 100-year lifespan. In all the sample cases in the study, operational carbon savings offset the added embodied carbon associated with higher insulation levels in about five years or less.

Yet the direction of the 2030 National Building Code increasingly emphasizes upfront embodied carbon. While reducing embodied emissions in construction is part of the solution, analyzing materials without considering how they actually perform over decades paints an incomplete and potentially misleading picture. Without operational carbon, we miss a huge part of the potential to reduce energy demand and slash emissions.

The study evaluated the “carbon payback period,” the time required for operational carbon savings to offset the additional embodied carbon emissions associated with higher insulation levels. Across all building archetypes, the payback ranged from approximately 3.1 to 5.1 years for buildings with an expected 75- to 100-year lifespan.

Too often, housing affordability is framed as the initial upfront cost of buying a home. Design savings leading to substandard energy performance might look like a good deal, but cheaper to build can become more expensive to live in. Lower-performance homes, often built at the expense of operational carbon, can force Canadians into higher utility bills and leave them more exposed to energy price volatility. Materials that save operational carbon and reduce utility costs must be accounted for and supported in the National Building Code.

Canada needs more housing. But we also need housing that will still perform decades from now, that we can afford to live in. 

Whether homes are heated with natural gas, oil, propane, or electricity generated from fossil fuels, energy use creates emissions. And while electrification is an important part of Canada’s climate future, we currently have limited zero-carbon electricity available across much of the country. 

So it’s just as true today, as it’s ever been: The cleanest energy is the energy we never need to use.