What's actually different about a "new-construction" window compared to a replacement window?

New-construction windows have a nailing flange that fastens directly to the framing before siding goes on, so they get installed as part of the wall's water-management system rather than fit into an already-finished opening. This gives a builder the chance to integrate flashing and the weather-resistive barrier correctly from the start, but it also means any shortcuts taken during that stage get sealed in permanently once the siding closes up.

What should I ask a contractor before they install windows on my new build here?

Ask specifically how they handle sill pan flashing and back dams, whether their flashing tape is compatible with your house wrap, and what fastener and hardware materials they use given the salt air exposure. A contractor who's worked coastal Whatcom County builds before should be able to answer these in detail without hesitation, not just point to the window brand's general installation manual.

Should I choose vinyl or fiberglass frames for a home exposed to salt air near Semiahmoo Bay?

Both hold up well in this climate since neither corrodes or rots, which is why we steer most clients toward one or the other for exposed coastal builds. Fiberglass costs more but handles temperature swings and long-term stability slightly better, while vinyl is a strong, lower-cost option as long as it's a quality, UV-stable formulation.

What glazing package makes sense for a new build with a lot of rain and gray-sky glare?

Dual-pane or triple-pane glass with argon fill and a Low-E coating tuned for the Pacific Northwest is the standard recommendation, since it balances heat retention through long damp winters with reasonable glare control. Warm-edge spacers are also worth specifying, since they reduce condensation risk at the glass edge in consistently humid conditions.

Does Whatcom County's building code affect what windows I can put in a new home near Peace Arch?

Yes — Washington State's energy code sets minimum U-factor requirements for windows, and bedroom or basement openings typically have egress size and operation requirements that must be met before drywall goes up. We build the window schedule around your project's specific code requirements up front so there are no surprises at inspection.

New-Construction Windows for Peace Arch Homes

Building New in the Peace Arch Area Means Building for the Water

If you're framing a new home in the Peace Arch area, you already know this isn't a generic building site. Homes here sit close to Semiahmoo Bay and the Salish Sea, exposed to marine air, wind-driven rain, and long stretches of gray, damp weather that don't let up for months. New-construction windows are one of the few building components that have to perform against all of that from day one, with no history of settling, no prior owner's fixes to inherit, and no second chances once the siding and trim go on around them.

That's the opportunity and the risk of new construction. Done right, the window openings in a new build can be sealed, flashed, and integrated with the water-resistive barrier better than almost any retrofit ever could be. Done wrong — even with a good window — you get the same moisture problems that plague older homes in this part of Whatcom County, just baked in from the start.

What Coastal Whatcom County Actually Does to a Window Opening

Salt Air

Airborne salt off the bay accelerates corrosion on anything metal that isn't properly rated for it — fasteners, hardware, flashing tape adhesives, and lower-grade aluminum components all age faster here than they would twenty or thirty miles inland. It's not dramatic, it's slow, and that's what makes it easy to overlook during construction.

Driving Rain

Wind off the water doesn't just drop rain straight down — it pushes it sideways and up under trim, sills, and any gap in the weather barrier. A window opening that would be fine in a sheltered inland lot can leak here if the flashing sequence isn't built to shed water outward at every layer, not just at the surface.

Moss and Prolonged Dampness

Long moss seasons mean extended periods where exterior surfaces near windows simply stay wet — on north-facing walls, under roof overhangs, and anywhere airflow is limited. Sills, trim, and cladding around the window opening need to be able to shed and dry, not just repel water once.

New Construction vs. Replacement: Why the Job Isn't the Same

A lot of window marketing lumps "replacement" and "new construction" together, but they're different jobs with different failure points.

Replacement windows go into an existing, already-clad opening. The surrounding wall assembly is fixed, and the installer has to work with what's there.
New-construction windows have a nailing flange and go in before the siding, over a wall that's still open — meaning the flashing, the weather-resistive barrier, and the window itself all get integrated as one continuous water-management system.

That means new construction gives you a real chance to build the envelope correctly, but it also means every shortcut taken during framing and rough-in becomes permanent the moment the siding closes over it. There's no "we'll deal with it later" in new construction — later is after the wall is finished.

Where New-Construction Window Jobs Actually Go Wrong

Almost every window leak we're called out to diagnose in older homes traces back to one of a handful of installation shortcuts — not the window itself failing. On a coastal site like this, those shortcuts cause problems faster.

Sill Pan and Back Dam

Every rough opening should get a sloped sill pan with a back dam, so any water that gets past the window drains back outside instead of pooling against the framing. Skipping this is the single most common cause of hidden rot around new-construction windows, and it's invisible once the trim goes on.

Flashing Sequence

Flashing tape and building paper or house wrap have to be layered like shingles — each piece lapping over the one below it — so water is always directed outward and down, never into a seam. On a wall exposed to driving rain, a reversed lap or a gap at a corner is exactly where water finds its way in.

Fastener and Hardware Corrosion Resistance

Standard fasteners and trim hardware corrode faster in salt-laden air. Corrosion-resistant fasteners and compatible flashing materials cost a little more up front and prevent staining, loosening, and premature failure later.

Sealant Compatibility

Not every sealant bonds well with every flashing tape or window frame material. Using mismatched products is a common reason perimeter seals fail years before they should, especially with the amount of expansion and contraction that comes from big temperature swings between damp winters and warm, dry summer stretches.

Choosing the Right Frame Material for a Peace Arch Build

There's no single "best" window frame — the right choice depends on exposure, budget, and how much maintenance you want to take on. Here's how the common options compare for a home exposed to salt air and heavy rain:

Frame Material	Moisture/Salt Air Performance	Maintenance	Typical Cost Tier
Vinyl	Good — won't corrode or rot; UV-stable formulations hold up well	Low	Lower to mid
Fiberglass	Excellent — very stable in wet, salty, temperature-swinging conditions	Low	Mid to higher
Aluminum-clad wood	Good exterior protection, but wood core needs sound flashing to avoid interior moisture issues	Moderate	Higher
Bare wood	Weakest in this climate without diligent upkeep and repainting	High	Varies
Aluminum (uninsulated)	Prone to condensation and, over time, corrosion near salt air unless properly rated	Moderate	Lower to mid

For most new builds in this area, we steer clients toward vinyl or fiberglass frames precisely because they don't give salt air or standing moisture anything to work on. If you want the look of wood on the interior with better exterior durability, a clad option can work — but it raises the importance of getting the flashing right, since any leak has a wood substrate to damage.

Glass and Glazing Choices

Glass matters as much as the frame. In this climate, we typically recommend:

Dual-pane or triple-pane glazing with argon fill for better thermal performance during long damp winters
Low-E coatings tuned for the Pacific Northwest — good solar heat retention without excessive summer glare
Warm-edge spacers to reduce condensation risk at the glass edge, which is more noticeable in consistently humid conditions
Impact-rated or laminated glass in exposed elevations if wind-driven debris is a concern for your specific lot

Meeting Code Without Cutting It Close

Whatcom County follows Washington State's energy and building codes, which set minimum requirements for window U-factor (insulating performance) and, in many cases, egress size and operation for bedrooms. On a new build, this isn't optional paperwork — it affects which products qualify and how the whole envelope's energy calculations pencil out. We build window specs around the code requirements for your specific project up front, rather than discovering a mismatch at inspection.

Our New-Construction Window Process

Whether we're working directly with your general contractor or you've brought us in as the window and siding trade for the build, our process stays the same:

Plan review: We check window schedules against the elevations and framing plan before anything is ordered, catching sizing or swing-direction mismatches early.
Rough opening verification: We confirm openings are square, level, and sized correctly before installation day — small framing errors are far cheaper to fix now than after cladding.
Sill pan and flashing installation: Sloped sill pans, back dams, and a shingle-lapped flashing sequence tied into the weather-resistive barrier, matched to this site's rain exposure.
Window setting and fastening: Units are set plumb, level, and square, shimmed correctly, and fastened with corrosion-resistant hardware sized for coastal exposure.
Air sealing and insulation: Gaps around the frame are sealed and insulated properly — not overpacked, which can bow frames, and not skipped, which leaves drafts and condensation paths.
Exterior trim and integration with siding: Flashing and trim details are finished so the window becomes part of a continuous water-shedding wall system, not a separate component siding gets built around.
Final inspection and documentation: We walk every opening before siding closes it up, since this is the last point where problems are cheap to fix.

Checklist: What to Confirm Before Your Windows Go In

Rough openings are framed square and to the correct dimensions for the ordered units
Sill pans with a back dam are specified for every opening, not just the most exposed walls
Flashing tape and house wrap or building paper are compatible products, installed shingle-style
Fasteners and exterior hardware are rated for coastal/salt-air exposure
Glazing package meets or exceeds Washington State energy code for your climate zone
Egress-required openings meet size and operation requirements before drywall goes up
Sealants used are compatible with both the flashing tape and the window frame material
A clear plan exists for how the window flashing ties into the siding water-management system

Why It Matters That We Already Work This Area

A lot of window problems in coastal Whatcom County homes aren't caused by bad products — they're caused by installers applying an inland approach to a marine-exposed wall. Flashing sequences, sealant choices, and fastener specs that are perfectly fine in a drier, more sheltered location aren't automatically fine a few hundred feet from Semiahmoo Bay. Crews who work this area regularly build in the extra margin for salt air and driving rain as a matter of habit, not as an afterthought when something starts leaking three years later.

We also work directly with builders and general contractors, which matters on a new-construction schedule — window delivery timing, rough opening tolerances, and sequencing with siding and trim all need to be coordinated so the job doesn't stall or get rushed at the one stage where rushing causes long-term damage.

Get a Straight Answer on Your Window Plan

If you're framing a new home or addition in the Peace Arch area and want a second set of eyes on the window schedule, flashing plan, or frame material choice, we're happy to take a look. We'll give you an honest read on what your specific site and exposure call for — no pressure, no upsell — along with a free estimate for the work. The form below is the fastest way to get that conversation started.