After the leaky condo crisis, BC's building code now requires rain screen wall assemblies. Here's what Strata councils need to know about modern siding systems.
British Columbia's leaky condo crisis of the 1990s and 2000s was one of the most expensive building failures in Canadian history. Thousands of wood-frame condominium buildings suffered catastrophic water intrusion due to face-sealed wall assemblies that trapped moisture inside the wall cavity. The remediation costs reached billions of dollars, and many Strata corporations faced special assessments of $20,000–$50,000+ per unit.
The crisis fundamentally changed how buildings are constructed in BC. The provincial building code now requires rain screen wall assemblies for most multi-story residential buildings. A rain screen system creates a drainage cavity between the exterior cladding (siding) and the building's weather-resistant barrier (house wrap or membrane). This cavity allows any water that penetrates the cladding to drain harmlessly down and out of the wall, rather than being trapped inside where it can rot framing and grow mold.
Modern rain screen siding systems for Strata buildings include: fiber cement panels (HardiePlank, HardiePanel) — the dominant choice for new construction and remediation projects due to their durability, fire resistance, and dimensional stability; vinyl siding with rain screen furring — an economical option for lower-rise buildings; metal panel systems — increasingly popular for modern architectural designs; and engineered wood siding — offering the appearance of real wood with improved moisture resistance.
For Strata buildings considering siding replacement, the key considerations are: code compliance (ensuring the new assembly meets current BC Building Code requirements for rain screen drainage), energy efficiency (adding or upgrading insulation during the re-clad process), window and door integration (ensuring proper flashing and sealant details at all penetrations), and long-term maintenance requirements (different cladding materials have very different maintenance needs and lifespans).
The cost of a full building re-clad with a rain screen system varies widely based on building size, existing conditions, and chosen materials. For a typical 4-story wood-frame building, budgets of $150–$250 per square foot of wall area are common. While this represents a significant investment, the protection against water damage and the improvement in energy efficiency often make it the most important capital project a Strata corporation will undertake.
Strata Property Services has been involved in siding replacement and building envelope remediation since our founding in 1989. Our SteelStud.ca division provides the structural framing expertise for complex re-clad projects, while our siding crews handle every major cladding system used in the Lower Mainland. From initial assessment through warranty completion, we manage the entire scope with the documentation and communication standards that Strata councils require. Call 604-761-1518 for a siding assessment.