Exterior Envelope Renovation

Envelope work is the renovation most homeowners put off the longest and regret putting off the longest. Siding looks fine until it doesn't. Single-pane or early double-pane windows cost the homeowner money every winter without ever announcing themselves. Walls with no rainscreen cavity behind the cladding don't fail on a sunny week in July, they fail in the fifth wet October after a small leak has been quietly soaking sheathing for years. Burnaby's character stock, the post-war and mid-century homes across Burnaby Heights, Capitol Hill, and the older blocks of South Burnaby, was built before rainscreen detailing was standard and well before continuous exterior insulation entered the vocabulary. Renovating the envelope is where the building science actually lives.

How do I know if my home needs a rainscreen retrofit?

Homes built before the late 1990s often have no rainscreen cavity, cladding attached directly to building paper over the sheathing, meaning any water that gets past the cladding has nowhere to drain and stays in the wall. Signs of trouble include staining, soft spots in siding, or musty smells near exterior walls. If you're re-cladding a home of this era for any reason, retrofitting a drained, vented rainscreen cavity during that work is close to the standard answer for a Lower Mainland envelope.

What is the difference between a siding refresh and a full envelope retrofit?

A siding refresh removes old cladding, inspects and repairs the sheathing and flashing, and re-clads, adding a rainscreen cavity where one is missing. A full envelope retrofit goes further, adding continuous exterior insulation, replacing windows, and often air-sealing rim joists and re-flashing transitions. The right scope depends on the home's age, the condition of the existing walls, and how long the owner plans to stay.

Should I add exterior insulation when re-cladding my home?

The moment the cladding is off and the sheathing is exposed is the only practical window to add continuous exterior insulation without paying to open the wall twice. Mineral wool and rigid foam are both used depending on the assembly, mineral wool is vapour-open and fire-resistant, rigid foam delivers more R-value per inch. We size the exterior insulation to the home's target performance level and check that the resulting wall assembly won't trap moisture at the dew point.

Should I choose double-glazed or triple-glazed windows for an envelope renovation?

A modern double-glazed unit with low-e coating and argon fill in a thermally-broken frame is a competent retrofit standard for most homes. Triple-glazed units with insulated frames are the right call for Step 4 or Step 5 energy targets, or for owners prioritizing winter comfort and sound reduction, though they're heavier and require checking the existing rough opening structure. On heritage and character homes, there's a real trade-off between visual continuity and performance that we lay out rather than assume.

Does an envelope renovation require a development permit in Burnaby?

Usually not. Envelope renovations typically need a building permit, and an electrical or plumbing permit if mechanical systems are touched, but don't normally trigger a development permit unless the cladding change crosses a heritage or character area design review threshold, or the work expands the building envelope. We submit the assemblies, manufacturer specs, and rainscreen detailing as part of the building permit package.

Can I mix mineral wool and rigid foam insulation on the same wall?

The insulation choice has to be evaluated as part of the full wall assembly, not selected independently, because the combination of exterior insulation type and any interior vapour retarder affects where moisture can condense within the wall. We design the assembly holistically based on the target performance level and what the existing structure can tolerate, rather than treating exterior insulation as an interchangeable upgrade.

Will an inspector need to see the weather-resistive barrier before cladding goes on?

Yes. The inspector typically wants to see the weather-resistive barrier (WRB) and flashings installed and detailed correctly before the new cladding covers them, since these layers can't be verified once the finish material is on. We build the schedule around that inspection happening on time so the re-cladding crew isn't held up waiting.

How long does an exterior envelope renovation take?

Timeline depends on the scope selected, a siding refresh moves faster than a full retrofit that adds continuous exterior insulation and replaces windows. Cladding material lead times and permit review time also factor in. We give a realistic schedule once the scope and materials are selected.