Bellevue Modern New Construction Siding — Hardie Lap & Panel + Custom Metal Coping + Cedar Soffits

Modern flat-roof new construction in Bellevue with the kind of architectural detailing that only works if every transition is built right. Architect-specified white HardiePlank lap and HardiePanel (Hardie Primed, field-painted) as the primary cladding, real cedar soffit overhead for warmth, custom-bent metal coping on every parapet, and continuous custom metal flashing at every reveal and window head. The brief from the architect: clean lines, sharp shadow detail, and an envelope built to handle Pacific Northwest exposure for the next 40 years — this is the kind of build that separates a careful Bellevue siding company in Bellevue from a generic install crew.

About this Bellevue modern new construction project

Modern architecture is unforgiving. On a craftsman or traditional build, a slightly off trim reveal disappears in the visual rhythm. On a modern build, every line is the design — a misaligned parapet coping or a clumsy flashing transition reads as a mistake from the curb. This Bellevue project lived or died on three things: parapet coping, cedar soffit precision, and the white lap-to-panel transitions reading as deliberate rather than accidental.

We came in fresh from the framer with bare sheathing — no tear-off, no surprises — ready to lay down the entire envelope from scratch in the right order: HydroGap WRB first, custom metal flashing integrated as it went up, then cladding. The architectural detailing required custom-bent metal at almost every transition, not the off-the-shelf bent flashing you can grab at the supplier.

What we specified

• HardiePlank® Lap (HZ10) Primed on the primary elevations — field-painted on-site by the painter to the architect-specified custom white — clean reveal lines, fastened per Hardie’s certified-installer HZ10 spec for the Pacific Northwest.
• HardiePanel® field at gable areas and architectural reveals, with intentional reveal lines at lap-to-panel transitions.
• Real cedar soffit overhead — warm natural wood, back-primed, properly ventilated, with stainless fasteners. Adds a deliberate organic note against the clean white lap.
• Custom metal coping on every parapet — bent on-site to exact dimensions, sealed and mechanically fastened, integrated with the WRB to keep water from migrating into the wall top. More on metal coping detail →
• Custom-bent metal flashing at every window head, sill, kickout intersection, and architectural reveal — not stock profiles. Each piece field-measured and bent to spec.
• HydroGap® Drainable WRB from Benjamin Obdyke as the envelope foundation. Why drainable WRB matters →
• Tamlyn aluminum XtremeTrim® corners — inside and outside. The architect specified clean reveal corners rather than traditional HardieTrim boards. We installed Tamlyn aluminum corner profiles at every outside corner and every inside corner — the resulting shadow line is sharp, the reveal is consistent, and the corner doesn’t telegraph as a wood trim board the way HardieTrim would.
• Custom-bent metal flashing at every other transition, reveal, window head, sill, and kickout intersection — field-measured and shop-bent for the exact reveal the architectural set required.
• Caulk and sealant at all butt joints and transitions, color-matched touch-up at every fastener head.

Why HardiePlank Primed instead of ColorPlus on this Bellevue project

Most of our Bellevue Hardie installs spec ColorPlus factory finish — it carries a 15-year fade warranty and arrives at the site already finished. On this modern build the architect specified a custom white that was not in the standard ColorPlus palette, so we ran HardiePlank Primed and coordinated with the painter to apply the finish coat on-site. The trade-off: paint refresh cycle is closer to 8–12 years instead of ColorPlus 15+, but the color match against the cedar accents and metal coping is exact. For modern builds where the white tone is part of the architectural design intent, Primed + field paint is the right call.

Tamlyn aluminum XtremeTrim® corners — inside and outside

Modern minimalist exteriors live or die on the corner detail. A traditional HardieTrim board at every outside corner reads as a wood-trim board even when painted to match — the proportions, the shadow, the way it interrupts the lap line all telegraph “builder default.” On this Bellevue project we ran Tamlyn aluminum XtremeTrim® corner profiles at every outside corner and every inside corner instead. The aluminum reveal is thinner, the shadow is sharper, and the corner reads as a deliberate architectural element rather than a trim board.

Inside corners get the same treatment — a Tamlyn aluminum inside-corner profile mechanically fastened to the framing before the lap goes up, with the lap edges butting cleanly into the channel. No back-cutting Hardie boards, no trim-and-caulk gymnastics at the inside corner, just a clean aluminum reveal that disappears visually and lets the architecture speak.

The cedar soffit detail

One of the design moves on this Bellevue project that we spent disproportionate time on: the cedar soffit. Real wood overhead reads warm, natural, and human against a clean white lap exterior — but only if it’s installed correctly. We back-primed every cedar board, used stainless fasteners, and ventilated the soffit with continuous strip vents so the cavity above can dry. The skylight cutout was field-measured and the boards were pre-cut so the cedar pattern reads continuously around the opening rather than getting interrupted.

Metal coping on every parapet

On a flat-roof modern build, the parapet coping is structural to the envelope — it’s what stops water from running into the wall top. Stock coping profiles don’t fit modern parapets cleanly because every parapet has slightly different proportions, returns, and architectural reveals. So we field-measured each parapet, bent custom coping pieces in our shop, and installed them with continuous concealed mechanical fasteners and full sealant beds underneath.

Critical detail: the coping integrates with the HydroGap WRB at the wall top. The metal extends down behind the cladding by enough to lap the WRB, sealed at the joint, so water that hits the parapet has zero path into the wall behind. Full metal coping installation guide for Seattle-area parapets →

Custom metal flashing around every window

Window detailing on a modern Bellevue build is where most installs lose the architectural intent. Stock head flashing and stock J-channel reveal as a generic builder default the moment you stand within ten feet of the window. On this project the architect specified a clean, continuous reveal at every window head, sill, and jamb — so we field-measured each opening and bent custom metal flashing in the shop.

The metal flashing wraps the window opening, integrates with the HydroGap WRB to keep water out of the wall, and finishes flush against the white HardiePlank lap with a tight reveal. Every kickout flashing at every roof intersection got the same custom treatment. The result is the kind of clean, sharp window detail that reads as deliberate from across the street — not as something that came off a shelf.

Install order on a Bellevue modern new construction

1. Walk every elevation against the architectural set before any WRB — especially modern parapet returns and architectural reveals where stock flashing won’t fit.
2. Install HydroGap drainable WRB across the entire substrate, shingle-style, sealed at every overlap and seam.
3. Field-measure every parapet, every window head, and every architectural reveal. Custom-bend metal flashing and coping pieces in the shop.
4. Install custom metal coping on every parapet first — tied to the WRB at the wall top so the water path is closed before any cladding goes up.
5. Integrate window and door flashings with the WRB — sill pan, head flashing with end dams, kickout flashings at every roof intersection.
6. Install vertical furring for rainscreen ventilation at the panel field areas, vented top and bottom with insect mesh.
7. Install HardiePlank lap on the primary elevations to HZ10 spec, with crisp horizontal reveals and proper fastener depth.
8. Install HardiePanel in the gable and architectural reveal fields with sealed butt joints.
9. Install cedar soffit overhead with back-priming, stainless fasteners, continuous ventilation, and field-cut detailing around skylights and feature openings.
10. Install Tamlyn aluminum XtremeTrim® corners at every outside corner and inside corner — clean reveal profile, mechanically fastened, integrated with the cladding edges.
11. Install custom-bent metal flashing at every other architectural transition and reveal. Color-matched touch-up at fastener heads, caulk-and-tool at every joint.

What this build buys the homeowner

1. Architectural intent that survives the build. Most modern Bellevue homes lose 20% of their visual quality between the architect’s rendering and the finished build because trim, flashing, and transitions get value-engineered. Custom metal coping and field-bent flashing protect the original design intent.
2. An envelope that meets Pacific Northwest exposure. HardiePlank in HZ10 has zero moisture absorption, and the integrated HydroGap WRB plus custom flashing gives the wall a 40-year service runway. Cedar soffit, properly back-primed and ventilated, lasts as long as the rest of the envelope.
3. Resale strength. Modern Bellevue homes with thoughtful detailing command premium pricing at sale. Buyers (and inspectors) recognize custom-bent flashing, real cedar soffit, and proper parapet coping as build quality — and the absence of those details as a future maintenance liability.

The takeaway for a Bellevue modern new construction siding project

Modern architecture demands modern detailing. If you’re building new in Bellevue and the architect has spec’d parapets, large window walls, or unconventional reveals, the install crew needs to be the kind that bends custom metal in the shop and detail-walks the elevations before any cladding goes up. As a Bellevue siding installation specialist, we treat new construction the same way we treat a re-side — envelope first, cladding second, custom detailing where the architecture demands it.