A new industry case study suggests that steel, concrete and mass timber can deliver near-identical results when evaluated on cost and environmental performance for mid-rise residential construction in the Greater Toronto Area.
The research, presented in December at The Buildings Show, examined a theoretical 12-storey, 287,000-square-foot L-shaped condominium tower designed to reflect typical market conditions. Engineering firm WSP and architecture studio mcCallumSather partnered with steel producer ArcelorMittal through its Steligence program to model three functionally equivalent versions of the same building, each using a different primary structural system.
Additional engineering input was provided by RJC and MTE. The teams compared structural weight, construction cost, build speed and life-cycle environmental impact, with the goal of isolating how material choice alone influences performance.
Standardized Building Model
The case study was structured around a single normalized design intended to mirror common development practices in the GTA. The building used consistent foundations, stairwells, envelope design and floor layouts across all three scenarios to ensure functional equivalency and avoid favouring any single material system.
This approach allowed the research team to focus on how steel, concrete and timber performed under identical design constraints rather than optimizing the structure for one material type.
Life-Cycle Environmental Analysis
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To assess sustainability, the study relied on life-cycle analysis using One Click LCA software and third-party-verified Environmental Product Declarations (EPDs). Global warming potential was used as the primary metric, with materials sourced locally where possible.
The materials analyzed included recycled and renewably produced structural steel, general-use low-carbon concrete compliant with Concrete Ontario standards and a mass-timber system combining British Columbia glue-laminated timber and Ontario-manufactured cross-laminated timber.
Results showed only modest variation in embodied carbon. Concrete recorded the highest global warming potential, followed closely by mass timber and then steel. All three options met the requirements of the Toronto Green Standard.
Comparable Construction Costs
Construction costs were also closely aligned. The steel option was estimated at $3.11 million, concrete at $3.12 million and timber at $3.01 million, placing all three within a narrow range for the same building form and performance criteria.
Researchers noted that cost differences were influenced more by design decisions and detailing than by the base material itself.
Construction Speed as the Main Variable
Where the systems diverged most clearly was in construction speed. After identical timelines for foundations and exterior cladding, the timber structure required an estimated 113 days to complete, compared with 157 days for steel and 190 days for concrete.
Data-Driven Design Trends
Project participants described the study as evidence that modern building design is shifting away from rule-of-thumb material selection towards data-driven decision-making supported by detailed modelling and collaboration across disciplines.
The findings indicate that, for typical high-density residential projects, sustainability targets and budget constraints can be achieved with any of the three major materials when they are applied strategically and supported by integrated design practices.
Images via Depositphotos
