What's the real difference between new-construction and replacement windows?

New-construction windows have a nailing flange that integrates directly into the wall's weather barrier before siding goes on, giving a continuous drainage path. Replacement windows are flangeless units set into an existing frame, relying more on sealant alone. New-construction is only possible during a build or full wall opening — it's not something you can retrofit later without removing siding.

What should I ask a contractor before hiring them for new-construction window installation?

Ask whether they'll handle the sill pan and flashing sequence themselves or leave it to another trade, since that handoff is where most failures start. Ask to see their flashing detail explained step by step, not just "we caulk it well." Also confirm they're licensed and bonded in Washington and ask how they coordinate with the siding or WRB installer if that's a separate crew.

Does it matter what brand of window I use, or is it mostly about the installation?

Both matter, but installation quality determines whether a good window performs like one. A well-flashed mid-range window will outlast a premium window installed with skipped steps. That said, stick with manufacturers that provide NFRC-labeled performance data and a clear written warranty, since that's your recourse if a unit fails on its own.

What do U-factor and SHGC ratings actually mean for a house out here?

U-factor measures how much heat escapes through the window — lower numbers mean better insulation, which matters most in our long heating season. SHGC measures how much solar heat comes through the glass, which matters more on south- and west-facing windows that get direct sun. Washington's energy code sets minimum thresholds for both, and your window schedule needs to meet them for permit approval.

Are there permit or code requirements specific to building near Kendall?

New construction in unincorporated Whatcom County, which covers the Kendall area, goes through Whatcom County permitting rather than the City of Lynden, and window performance still has to meet Washington State Energy Code minimums. Requirements can vary by specific project type and site conditions, so it's worth confirming details with the county or your builder before finalizing your window order.

New-Construction Windows for Kendall, WA New Builds

Building New in Kendall? The Windows Are Where Most Long-Term Problems Start

Kendall sits in the rural stretch of Whatcom County east of Lynden, where new homes and shops are still going up on acreage lots along the foothills toward Mt. Baker. If you're framing a new house or outbuilding out here, the window install is one of the few construction steps you genuinely cannot fix later without tearing into finished walls. Get it right during the build and you won't think about it again for decades. Get it wrong and you're chasing rot, fogged glass, or drafts within a few winters — usually right when the warranty on the house has run out.

We install new-construction windows as part of full siding and exterior envelope work, which means we're not just setting units in an opening — we're tying them into the weather-resistive barrier, flashing them so water sheds correctly, and making sure the window and the siding system work together instead of fighting each other. That coordination matters more in this climate than most people realize.

What Kendall's Climate Actually Does to a Window Install

Whatcom County gets a long, wet fall-through-spring stretch, and out toward Kendall you're catching driving rain off the foothills on top of the general marine-influenced weather that moves in from the Strait and Bellingham Bay. Add a long moss season — anything shaded or slow to dry stays damp for months — and you've got conditions that will find every gap in a window's flashing detail.

New-construction windows aren't sealed against weather the way a finished, painted wall is. They rely entirely on the installer building a correct drainage path: water that gets behind the siding or through incidental gaps has to be directed back out, not trapped against the rough opening framing. A few climate-specific realities we plan around:

Wind-driven rain pushes water sideways and upward, not just straight down — flashing laps have to account for that, not just shed water downhill.
Long damp stretches mean any trapped moisture behind a window doesn't get a chance to dry out before the next storm arrives.
Moss and algae growth on shaded elevations signals chronic dampness — the same conditions that rot sill framing if a window wasn't flashed correctly at rough-in.
Temperature swings between summer highs and winter lows put real stress on sealants and expansion gaps if they weren't sized correctly.

None of this is exotic. It's standard Pacific Northwest building science. But it only works if it's actually followed at the framing stage, not assumed.

New-Construction vs. Replacement: Why the Method Is Completely Different

A lot of homeowners ask us why we talk about new-construction windows separately from replacement windows. The answer is that they're installed with entirely different hardware and sequencing.

New-construction windows have a nailing flange around the perimeter that gets integrated directly into the wall's weather-resistive barrier (WRB) before siding goes on. Replacement windows are typically flangeless "pocket" units that get inserted into an existing frame with no direct connection to the wall wrap. On a new build, you get the flange method — and that's a genuine advantage, because it means the window becomes part of a continuous drainage plane instead of relying on caulk alone.

The trade-off is that it has to be done in the right order, by whoever is also handling the WRB and siding. If the window installer and the siding crew are two different companies working off two different schedules, the flashing handoff between them is exactly where mistakes creep in — a WRB lapped the wrong direction, a sill pan skipped to save time, house wrap taped over a flange instead of under it. We do both scopes, which removes that seam entirely.

What Correct New-Construction Window Installation Actually Involves

Rough opening checked for square, level, and correct dimension before the window ever arrives on site
Sloped sill pan installed at the rough sill so any water that gets past the window drains back outward, not into the wall cavity
Window set in the opening, shimmed plumb and square, and fastened per the manufacturer's schedule — not "close enough"
Flashing tape or flexible flashing lapped in correct shingle order: sill first, then jambs, then head, so each layer sheds onto the one below it
WRB integrated over the head flashing and under the jamb flashing, maintaining a continuous drainage path down to the sill pan
Backer rod and low-expansion sealant at the interior gap, sized to allow for seasonal movement without gapping or blowing out
Exterior trim and siding tied in without trapping moisture against the flange or leaving unsealed penetrations

Every one of those steps is inspectable during the build. Once siding is on, most of them are invisible — which is exactly why it matters who does it and how carefully, not just whether it "looks finished" afterward.

Choosing the Right Window for a Kendall Build

Framing material is a real decision, not just a budget line. For new construction in this climate, we look at how each option handles moisture exposure, temperature swings, and long-term maintenance — since a lot of Kendall properties are on acreage with more sun and wind exposure than a tight in-town lot.

Frame Material	Moisture Tolerance	Maintenance	Typical Fit For
Vinyl	Good — won't rot; can flex slightly in temperature swings	Low — no painting, occasional cleaning	Most new-construction homes; strong value for performance
Fiberglass	Excellent — very stable through wet/dry and hot/cold cycles	Low — durable finish, minimal upkeep	Larger openings, exposed elevations, longer ownership horizon
Wood-clad	Good on the exterior clad face; interior wood needs protection from condensation	Moderate — interior finish maintenance over time	Homeowners prioritizing a wood interior look

We don't push one material on every job. We'll talk through your budget, the exposure on each elevation of the house, and how long you plan to own the property, and land on what actually makes sense — not the option with the biggest margin.

Glass Performance for This Climate

Washington's energy code sets minimum performance requirements for new-construction windows, and in Whatcom County those numbers matter practically, not just on paper. Look for:

U-factor — measures heat loss through the window; lower is better for our heating-dominant climate
Solar Heat Gain Coefficient (SHGC) — matters most on south and west elevations that get direct sun
NFRC label — the independent rating every code-compliant window should carry; ask to see it, don't take a verbal number
Double vs. triple pane — triple pane adds cost and weight but meaningfully cuts heat loss and sound transfer on exposed sites

How the Process Works

For a new build in Kendall, we typically get involved once framing is up and before the WRB goes on, so window flashing and siding weatherproofing are planned as one continuous system rather than two separate trades guessing at each other's work.

Plan review and takeoff — we go through the window schedule with you or your builder, confirm sizes, swing directions, and any performance requirements for permit.
Rough opening inspection — every opening gets checked before install day; problems here are cheap to fix now and expensive to fix later.
Sill pan and flashing install — the drainage detail that does the real work, built to shed water outward under wind-driven rain.
Window setting — plumb, level, square, fastened to manufacturer spec.
WRB and siding integration — since we handle the siding too, the wrap, flashing, and cladding are sequenced correctly the first time.
Final seal and walkthrough — interior sealant, exterior trim, and a walk-through so you know what was done and why.

Why Local Experience in This Part of the County Matters

Kendall properties often mean larger lots, more wind exposure, well and septic instead of city utilities, and sometimes a longer driveway before you're even at the house — practical things that affect scheduling and site access on a new build. More importantly, the exposure profile out here is different from a sheltered in-town lot in Lynden: less windbreak from neighboring structures, more direct weather off open fields. A crew that's worked new construction across Whatcom County knows to flash for that exposure rather than installing to a generic spec sheet.

We're also on-site for the siding portion regardless, so there's no gap between "the window guy" and "the siding guy" pointing at each other if something needs adjusting. One crew, one sequence, one point of accountability for how water moves around your window openings for the life of the house.

What This Costs — And What Drives the Range

New-construction window pricing depends on unit count, size, glass package, and frame material, so we won't quote a number here that doesn't mean anything without seeing your plans. What we can tell you is what actually moves the price:

Number and size of openings, and how many are larger picture or slider units versus standard operable windows
Frame material chosen (vinyl, fiberglass, or wood-clad)
Glass package — double vs. triple pane, and any specialty coatings for sun exposure
Site access and how far along framing is when we start
Whether we're also handling the siding and WRB, which often saves cost versus coordinating two separate contractors

Get a Straight Answer for Your Kendall Build

If you're planning a new home or outbuilding in the Kendall area and want windows installed the way this climate actually requires — not just installed fast — we're glad to walk your plans with you. Fill out the form below for a free, no-pressure estimate, and we'll give you a straightforward read on window options, timing, and cost for your specific build.