Ontario Construction News staff writer
The Responsible Buildings Pact, launched in June 2024 by the Climate Smart Buildings Alliance (CSBA), outlines a process for developers, architects, engineers and consultants to evaluate and report on their use of low-carbon materials, beginning with concrete.
The pact is the flagship initiative of CSBA, a non-profit founded in 2023 by EllisDon Corporation, Mattamy Homes and RBC. Its membership has since grown to include AtkinsRéalis, Wesgroup, CIBC, DIALOG and PCL, among others.
In its first year, participating organizations assessed 109 projects, collectively avoiding more than 60,000 tonnes of greenhouse gas emissions — the equivalent of taking 13,000 cars off the road for a year.
“Low-carbon concrete isn’t right for every application, but there are many situations where it works well,” said David Messer, executive director of CSBA. “This initiative is about building a culture where companies consistently explore those opportunities and share what they learn.”
Messer said most success was found in below-grade uses, such as foundations and slab-on-grade construction, where longer curing times are more acceptable. Almost two-thirds of participants reported a cost premium of 0 to 5 per cent for lower-carbon mixes.
The 25 organizations that participated in the pilot year committed to integrating a review process on at least five projects each. While uptake varied depending on project timelines, Messer called the response “very exciting.”
“Larger projects had a clearer business case for adoption because they could benefit from bulk purchasing and better pricing,” he said.
The pact is governed by a multi-organization steering committee and requires signatories to report annually on material evaluation efforts and, where feasible, adopt or recommend lower-carbon alternatives.
Looking ahead, CSBA plans to expand the scope of the pact to include structural steel elements such as rebar and siding. The alliance also aims to grow participation to 100 signatories by the end of the next reporting period.
“The pilot year has shown how companies can take practical steps toward more sustainable procurement and do so in a way that aligns with their peers,” said Messer. “We’re also working with suppliers to make lower-carbon options the default wherever they make business sense.”
Funding and support for the initiative were not disclosed. More information is available at climatesmartbuildings.ca.