Vancouver to Grade Building Stock for Earthquake Risk
Vancouver will inventory and grade its building stock for earthquake risk by screening structures from the exterior to identify those most likely to fail. Micah Hilt, the city's lead seismic policy planner, presented the plan to council.
No major Canadian city is more earthquake-exposed than Vancouver, which sits above the Cascadia megathrust. Models give a one-in-five chance of a very strong earthquake within 50 years.
How the Grading System Will Work
Hilt intends to have a design professional inspect each building from the exterior and assign a risk grade, as Seattle did for its unreinforced masonry campaign. Grades will inform policy, retrofit incentives, and priority ordering.
The Potential Impact
A 2024 study co-authored by Hilt and Tiegan Hobbs estimates a 7.2-magnitude quake in the Georgia Strait could cause:
- Up to 1,350 dead or severely injured
- Nearly 6,100 buildings heavily damaged
- Displacement of over a third of residents and workers for months
- Direct losses near $17 billion
Where the Risk is Concentrated
Five building types account for nearly 80% of risk, concentrated in six neighbourhoods carrying about 65% of risk. Single-room-occupancy hotels are among the most exposed.
A Contentious Issue
Tenant advocates want grades made public; property owners warn that publishing building-level risk would harm leasing, insurance, and lending.
Background
Seattle, San Francisco, and New Zealand have built registers that guide retrofit programs. New Zealand is currently adjusting its scheme.
Timber Construction and Seismic Performance
Engineered wood is considered for new construction because its lightness reduces seismic forces. Shake-table testing showed a 10-storey cross-laminated timber tower at UC San Diego survived over 100 simulated quakes without structural damage, self-centring after each run.
A University of Auckland test of a two-storey cross-laminated timber building withstood 100 strong shakes and returned to centre each time, with main timber elements undamaged.
Japan's seismic codes, informed by the 1923 Great Kanto earthquake, use framed systems and heavy connections. Vancouver engineers judged mass timber five times lighter than concrete and easier to design to higher seismic standards when encapsulated timber was cleared to 18 storeys in 2024.