Wood vs. Vinyl Windows: Which Survives the North Shore Climate

Rot is the North Shore's real test, and vinyl doesn't fail it

North Vancouver gets close to 2,000 millimetres of rain a year, most of it between October and March, often driven sideways by wind off Howe Sound. That is the condition wood window frames have to survive, over and over, for decades. Wood is a natural material with grain and end grain, and water finds the end grain fastest, usually at the corners where two pieces of the frame meet.

A well-maintained wood window, painted or stained on schedule with the joints caulked and checked yearly, can last 30 to 40 years on this coast. The word doing the work in that sentence is maintained. Skip two paint cycles, let a caulk joint open at a corner, or leave a sill unpainted after a repair, and water gets into the wood fibre where you can't see it. By the time paint is visibly failing on the surface, rot is often already established underneath.

Vinyl has no grain and no end grain. It doesn't absorb water, it doesn't need paint, and it doesn't rot. That single fact is why vinyl dominates North Shore replacement window jobs: it removes the maintenance dependency that wood carries. A vinyl frame's failure mode is different. The welded corners can separate after 20 to 25 years of thermal cycling, and the frame can warp or discolour in full southwest sun exposure, which several West Vancouver waterfront lots get in volume. Neither of those is rot, and neither one lets water into a wall cavity the way a failed wood corner does.

Condensation shows up differently on each material

Condensation on a window is moisture in the house air turning back to liquid water where it touches a cold surface, the same thing that happens on a cold glass in summer. It has more to do with the glass unit and the indoor humidity than the frame, but the frame material changes what happens once that water forms.

Vinyl has a lower thermal conductivity than aluminum but a higher one than wood, so a vinyl frame runs slightly colder on its interior face in winter, and that's where you'll see condensation first if the house is running humid. Wood is a better insulator at the frame itself, which means the frame surface stays a bit warmer and condensation shows there less, but it also means that any spot where paint has failed becomes the place water sits longest, since bare wood holds moisture against the surface rather than shedding it.

In practice, condensation on a North Shore window is usually solved the same way regardless of frame material: fix the humidity source (a bathroom fan not ducted outside, or a crawl space venting into the house) before blaming the window. But if condensation is going to become a maintenance problem, it becomes one faster on a wood sill that isn't sealed than on a vinyl one that can't absorb the water in the first place.

What each material actually costs installed

Vinyl is the budget-conscious default for a reason, and wood carries a real premium that has to buy something specific to be worth it.

The table below reflects standard sizes in a normal wall opening. A large custom shape, a heavy casement, or an oversized picture window pushes any of these numbers up, and the gap between vinyl and wood generally holds proportionally across sizes.

Clad wood splits the difference, and it's what we recommend most

The option that comes up most often once a homeowner hears the full trade-off is clad wood: a wood frame and sash on the inside, wrapped in aluminum or fibreglass on the exterior face where the weather actually hits. The exterior cladding takes the rain and UV exposure that would otherwise attack painted wood, and the interior keeps the warmer look and feel that vinyl can't fully match, especially on a character or heritage home where the sightlines and profile matter.

Clad wood costs more than plain painted wood up front, usually $200 to $400 more per window, but the maintenance schedule drops close to vinyl's, because the exterior face isn't the thing failing anymore. On Caulfeild and Lower Caulfeild heritage-review properties, and on British Properties homes where street-facing appearance carries real weight, this is the material we spec most often. It isn't the cheapest option and it isn't trying to be.

Where the BC Building Code numbers apply to both

Whichever frame material you choose, the glass unit has to hit the same code number. The BC Building Code sets a maximum U-value for windows and doors by climate zone in Table 9.36.2.7.-A. Most of the North Shore sits in Zone 4, where the ceiling is 1.84 W/(m2.K), the standard measure of how fast heat moves through the whole window assembly. Lower means better performance. If you're chasing the BC Hydro window rebate instead of just the code minimum, that threshold drops to 1.22 or less, a meaningfully tighter target.

Frame material affects how hard it is to hit that number. Vinyl's multi-chambered frame design is inherently good at slowing heat flow, so a double-glazed vinyl unit often reaches 1.22 without much trouble. Wood is naturally a good insulator too, but true divided lite wood windows, the kind with real muntin bars separating individual panes rather than a decorative grille over one sheet of glass, have more frame-to-glass ratio and more thermal breaks to manage. On a heritage-style wood window with true divided lites, triple glazing is often what it takes to hit 1.22, and that adds cost and weight on top of the wood premium already on the table.

None of this changes by walking into a showroom and asking whether a product 'meets code.' Ask for the U-value printed on the National Fenestration Rating Council or equivalent label, in writing, before you order. A quote without that number on it isn't a complete quote.

Which one we spec, and when

On a straightforward North Vancouver renovation where the budget is the deciding factor and the house isn't under heritage review, vinyl is the honest recommendation for most rooms. It performs well, it costs less, and it removes the maintenance schedule from the homeowner's list entirely. We spec vinyl on the large majority of full-house window replacements we quote.

Wood or clad wood earns its premium on three kinds of projects: a heritage-designated or heritage-review property where the sightlines and sash profile are part of what's being protected, a high-end custom renovation where the interior look of the frame matters as much as the performance, and street-facing elevations in neighbourhoods where character is part of the property value. On the same house we'll sometimes spec clad wood on the front elevation and vinyl on the back and sides, where nobody but the homeowner will ever see the difference.

What we won't do is spec plain painted wood on a full exterior exposure without a clear conversation about the repaint schedule that comes with it. That conversation is the one homeowners tell us nobody else had with them, right up until a sill needs replacing at year eighteen.