Before any crew pulls the first course of old siding off a home in Bellingham, Ferndale, Lynden, Blaine, Birch Bay, Sudden Valley, or out on Lummi Island, it helps to know what's usually hiding underneath. Whatcom County doesn't deal with hurricanes, but it deals with something just as hard on a wall assembly over time: months of steady, low-intensity rain, wind-driven rain that comes sideways off Bellingham Bay and the Strait of Georgia during winter storms, and enough persistent shade and humidity to grow moss and black algae on the north- and west-facing walls that rarely dry out between storms. In the foothill neighborhoods around Lake Whatcom and Sudden Valley, add freeze-thaw cycling — nights below freezing followed by wet, above-freezing days — which works water deeper into any crack or gap it finds in siding, trim, or caulk.
None of that shows up as dramatic storm damage. It shows up slowly, as soft trim, a damp smell in a crawlspace, or a stain that's been ignored for a few winters. That's the real reason a pre-residing checklist matters here: re-siding is the one point in a home's life when the wall assembly is actually opened up and can be checked, corrected, and brought closer to current Washington State Energy Code expectations before it's covered again for another two or three decades.
If sheathing tests soft, the rot has to be cut back to solid wood and replaced — covering it just relocates the problem behind new material for another decade. If moisture turns up in a crawlspace or wall cavity, the source needs to be traced and corrected (grading, a downspout, a flashing detail) before new siding goes on, or the new assembly will fail the same way the old one did, just more slowly. If ventilation is blocked or undersized, it's worth correcting as part of the same project, since siding removal is the easiest window anyone will have to reach vents and soffits that are otherwise hard to access. Repairs at this stage range widely — a single rotted band board section is a modest fix, while structural framing repair or a full re-wrap of a wall is a bigger scope — but it's rarely worth skipping. Covering a known problem doesn't make it go away; it just means the next contractor finds it in worse shape.
Homeowners can reasonably handle the visual parts of this checklist on their own — a screwdriver test, a walk around the foundation, a look in the crawlspace with a flashlight. Once anything comes back a fail — soft sheathing, rot in a rim joist, active moisture, or damaged flashing at a load-bearing connection like a deck ledger — it's worth bringing in a licensed contractor to scope the full extent of the damage before committing to a residing plan, since what's visible at the surface isn't always where it stops. It's also worth involving a professional early on a multi-story home on a sloped foothill lot, on any wall near power lines, or whenever there's a real question about whether existing insulation and moisture control meet current code, since the answer changes what can be closed back up versus what needs to stay open for a look. Alpine Exteriors handles these assessments as a standard part of its estimate process for homes throughout Whatcom County, and can walk a homeowner through which items on this list matter most for their specific house.
It depends on the size of the home and how much repair work turns up once old siding comes off, but rain is the bigger variable than square footage. Most contractors familiar with this region, including Alpine Exteriors, sequence work in sections and keep exposed wall areas covered with temporary weather protection overnight and between work days, rather than opening an entire elevation at once during the wetter months.
Residing alone is sometimes exempt from permitting depending on scope, but the moment work involves structural repair, changes to the weather-resistive barrier, or added insulation that affects the wall assembly, it typically needs to go through the local building department. A licensed contractor can confirm what applies to a specific project before work starts.
Sometimes, but it isn't a substitute for this checklist. Overlaying siding without inspecting what's underneath means any existing rot, moisture, or missing flashing stays hidden and keeps working on the wall, just under two layers instead of one. In a climate this wet, most contractors recommend at least selective removal to check high-risk areas even if a full tear-off isn't planned.
Full compliance depends on the scope of the project and how the existing wall assembly is built, but residing is a genuine opportunity to add continuous insulation and improve air sealing in ways that are much harder to do without removing the exterior cladding. It's worth discussing target R-values with a contractor before the project starts, since retrofitting further later is far more disruptive.
A checklist is a useful starting point, but a physical inspection catches what a walk-around can't. Alpine Exteriors, licensed in Washington as ALPINI751OW, offers pre-residing assessments for homeowners across Bellingham, Ferndale, Lynden, Blaine, Birch Bay, Sudden Valley, and the surrounding islands — a chance to find out what's really behind the old siding before committing to a full project scope.