Ferndale Siding "Custom windows" covers more ground than most homeowners expect. It's not just a fancy shape or an oversized picture window — it's any window that doesn't come off a manufacturer's shelf in a standard size, and that includes odd-sized replacements in older homes, additions where the opening doesn't match anything in a catalog, and specialty shapes chosen to make the most of a water view. In Fairhaven, close to Bellingham Bay, we run into all of those situations, and the water adds a weatherproofing challenge on top of the fit challenge that a straightforward inland replacement doesn't have to deal with.
Why Fairhaven Homes End Up Needing Custom Windows
A few things push window projects here into custom territory more often than in a typical inland neighborhood. Homes close to the water were often built to whatever dimensions made sense for the site and the view, not to a standardized window catalog, so a straight swap can mean either a special-order unit or reframing the opening — and reframing brings its own cost and disruption. Additions and remodels create openings that don't match anything original to the house. And a number of homes in this part of Fairhaven were designed with picture windows, bays, or larger-than-standard openings specifically to capture a water or territorial view, which by definition puts them outside stock sizing.
None of that is unusual for us — it's a routine part of window work this close to Bellingham Bay. But it does change how the project starts: with careful field measurement, an honest conversation about what the opening actually allows, and realistic expectations on lead time, since custom units are built to order rather than pulled off a shelf.
The Climate Factor Custom Windows Can't Ignore
Fairhaven's proximity to the water puts homes here in a tougher environment than a manufacturer's standard installation guidance assumes. Salt-laden air accelerates corrosion on hardware, fasteners, and lower-grade frame components faster than it would a few miles inland. Storms drive rain sideways into walls instead of letting gravity handle it, which means water finds gaps that would never get tested in a calmer climate. And the shaded, damp yards common on wooded or north-facing lots around here support a moss season that can run most of the year, holding moisture against sills, trim, and cladding far longer than a drier region would allow.
Custom windows raise the stakes on all of that. A larger picture window or a projecting bay has more perimeter to flash correctly, more glass area for wind load to push against, and often a more complex roofline or seat detail where water can collect if it isn't built right. An arched or specialty-shaped opening has curved or angled cuts in the wall assembly that are harder to flash cleanly than a plain rectangle. None of this means custom windows are a bad idea for a Fairhaven home — it means the installation has to account for the added complexity instead of treating it like a routine stock swap.
Where the Risk Actually Lives
It's rarely the glass or the frame material that fails first on a custom unit. It's the transition points — where a bay window's roof meets the main wall, where a picture window's wide sill meets the siding below it, where an arched top gets cut into the wall assembly. Those spots need extra flashing attention, and they're also the spots a rushed installation is most likely to shortcut, because they simply take more time than a standard opening.
Custom Window Types We Build For
Custom doesn't mean one thing — the approach changes depending on what's actually being built or replaced.
- Non-standard replacement sizes — matching an existing opening in an older home that predates modern window sizing standards
- Bay and bow windows — projecting units that add interior space and views but require their own roof, support, and flashing system
- Picture and large-format windows — fixed, non-operating units used to maximize a water or territorial view, with more glass to manage structurally
- Arched, angled, or specialty-shaped openings — architectural details that require custom-cut units and matching custom flashing
- Egress and code-driven openings — bedroom or basement additions where the size is dictated by code minimums, not convenience
- Matched sets for additions — new windows that need to sightline correctly with the existing windows on the house
What a Correct Custom Window Job Involves
Measuring and Ordering
Custom work starts with precise field measurement, not a catalog lookup. We measure the actual opening, note any out-of-square or out-of-level conditions common in older homes near the water, and account for what the finished exterior trim and flashing will need in terms of clearance. Because custom units are built to order, this step also sets expectations on lead time — a custom window typically takes weeks longer to arrive than a stock size, and we'll give you a realistic timeline before you commit rather than a best-case guess.
Opening Prep and Structural Considerations
Larger custom units — bay windows especially — sometimes need structural support beyond what a standard opening requires, since they carry more weight and project outward from the wall plane. We evaluate that as part of the assessment, not as a surprise mid-project. On older homes, this is also where we typically find out whether the original framing or flashing around the opening needs correction before a new unit goes in.
Flashing and Weatherproofing
This is the step that matters most this close to the water. Every custom shape changes how flashing has to be sequenced — a bay window's roof needs its own weatherproofing separate from the wall flashing below it, a picture window's wide sill needs to shed water outward instead of letting it pool, and an arched top needs flashing cut and lapped to match the curve rather than a straight run. We build the flashing plan around the specific shape of the opening, not a generic template pulled from a manufacturer's install sheet.
Finish and Trim Integration
Custom windows often sit in the most visible spots on a house — a bay window facing the street, a picture window centered on a water view — so the trim and finish work has to match the rest of the exterior cleanly. We plan that integration before the window arrives so the finished result looks intentional, not added on.
A Quick Checklist Before You Order
- Confirm the opening has been field-measured, not estimated from old plans or a rough guess
- Ask what the flashing plan looks like for the specific shape you're getting, not a generic answer
- Get a realistic lead time in writing before you commit to a schedule
- Ask whether the opening needs structural review, especially for bay or oversized units
- Confirm what's covered under warranty — the window unit and the installation labor are often separate
- Ask how trim and finish will be matched to the rest of the exterior
Our Process, Start to Finish
- On-site assessment — we measure the opening, check square and level, and evaluate any structural or flashing concerns specific to the shape or size involved
- Honest recommendation — custom order, modified stock size, or opening reframe, explained with the reasoning, not just whatever's fastest to sell
- Ordering and lead time — we give you a realistic timeline for the custom unit to arrive, since this isn't a same-week job
- Removal and opening prep — the old unit comes out carefully, and any hidden issues with the existing opening get addressed before the new window goes in
- Installation and flashing — the new unit is set, shimmed, and flashed to a sequence built for its specific shape and size
- Trim and finish — exterior trim is integrated to match the surrounding siding and architecture
Costs and Trade-Offs: Custom vs. Stock
What Actually Changes
| Factor | Stock Window | Custom Window |
|---|---|---|
| Lead time | Often available quickly from local stock | Built to order — expect weeks, not days, depending on complexity |
| Fit | Standard sizes only — reframing needed if the opening doesn't match | Matched to the exact opening or design intent |
| Flashing complexity | Straightforward, well-documented rectangular details | Shape-specific — bay roofs, arched cuts, or wide sills each need their own plan |
| Structural review | Rarely needed for a like-for-like swap | Often needed for bay, bow, or oversized units |
| Cost | Lower, especially for common sizes | Higher — reflects the manufacturing and labor complexity |
| Best fit | Simple replacements in standard openings | Older homes, additions, architectural features, or view-driven designs |
What Drives Cost
We won't quote a number without seeing the opening, but the factors that move price on custom work are consistent:
| Factor | Why It Matters |
|---|---|
| Size and glass area | More glass and larger units cost more to manufacture and are heavier to install |
| Shape complexity | Arched, angled, or curved units require specialty manufacturing and more flashing labor |
| Structural work | Bay and bow windows sometimes need added support framing |
| Frame material | Vinyl, fiberglass, and wood-clad units differ in both material cost and long-term maintenance |
| Opening condition | Rot, old flashing failures, or out-of-square framing add repair work before the new unit goes in |
| Number of units | A matched set for an addition or full-house project typically has better per-unit economics than a single window |
Frame Materials for This Climate
Frame material matters even more on a custom unit, since a larger or more exposed window has more surface area for salt air and moisture to work against. We'll walk through the honest trade-offs for your specific opening rather than defaulting to whatever's easiest to install. In general, fiberglass and vinyl frames hold up to sustained coastal moisture with less ongoing maintenance than an all-wood exterior finish, which is why we lead with them on weather-facing custom installs near Bellingham Bay — a wood-clad interior with a low-maintenance exterior cladding can still be the right call when the interior look matters and the exterior is properly protected.
Why Local Experience Matters for This Kind of Work
Manufacturer installation guides are written for average, standard-size conditions. Custom windows in Fairhaven rarely fit that description, and the climate doesn't either — salt air, wind-driven rain, and a long moss season stack the deck against a shortcut installation more than they would in a drier, calmer market further inland. A crew that has actually built out bay windows, flashed arched openings, and reframed odd-sized rough openings this close to the water in Whatcom County knows which details in the manufacturer's guidance are non-negotiable here, and where extra time on flashing or sealant is worth it even when it isn't strictly required elsewhere.
That experience shows up in decisions that don't make it into a sales conversation — how a bay window's roof ties into the main wall's water management, how much lap a flashing course needs on an arched opening, when a sill needs a sloped composite cap instead of relying on caulk. Those are the details that decide whether a custom window is still performing cleanly in fifteen years or showing rot and drafts in five.
Ready When You Are
If you're planning an addition, replacing an odd-sized opening in an older Fairhaven home, or considering a bay or picture window to take advantage of a water view, it's worth having someone look at the specific opening before you start pricing units. We offer free, no-pressure estimates for custom window projects in Fairhaven and the surrounding Ferndale area — use the form below to get a time on the schedule.