Plenty of Lafayette's ranch and custom hillside homes are still running their original single-pane windows — and in a town of hot, dry summers and cool, damp winters in the shaded canyons, those windows are usually the weakest link in the comfort of the house. Bay Area Siding Company, a Larkspur-based (Marin) siding and window contractor, replaces and installs windows across Lafayette: measuring, glass and frame selection, permitting where it's required, removal, flashing and air-sealing, and a final walkthrough.

Ready to talk it through? Request an estimate or call (415) 619-5167.

When windows are worth replacing

Older units tend to tell on themselves:

• Drafts and cold spots at the glass with the window shut — single-pane glass with no Low-E coating
• Fog or moisture trapped between the panes — a failed seal on a dual-pane unit, which can only be replaced, not repaired
• Sashes that stick, drop, or won't lock — swollen wood, painted-shut frames, or worn balances
• Rot or soft wood at the sill or surround, common on the damp, shaded elevations
• Rooms that never hold temperature through Lafayette's summer heat or a wet winter

The three decisions that matter

• Glass and energy performance. Dual-pane insulated glass with a Low-E coating is the baseline. California's Title 24 energy code sets the maximum U-factor and SHGC for replacement windows, and those numbers depend on the climate zone and the code cycle in effect — so rather than quote a fixed figure, we confirm the current requirement at permit time and spec units that meet it.
• Frame material. Vinyl, fiberglass, aluminum-clad wood, and aluminum each balance cost, thermal performance, and appearance differently. On Lafayette's custom and wood-trimmed homes, clad-wood or a frame profile chosen to respect the original opening often looks best.
• Retrofit versus new-construction install. A retrofit (insert) install keeps the existing frame and is less invasive; a new-construction (full-frame) install removes the window to the rough opening so the flashing can be fully renewed — the right call where there's rot or past water intrusion. We do both, and recommend based on what the opening is actually in.

Choosing a brand

We install several lines and can compare them for your home and budget. Start at the window replacement hub, then look at the specifics for Anlin, Milgard, Andersen, Marvin, and Pella. We also install aluminum windows where they fit the home.

Permits in Lafayette — the in-kind wrinkle

This is where Lafayette has a useful quirk. The city administers permits through its Planning & Building Department, with plan review and inspection contracted to the Contra Costa County Building Inspection Division. Lafayette's guidance lists like-for-like window replacements ("in-kind") as exempt from a permit — but new or changed windows and skylights are not exempt. In practice, swapping a window for the same size and type in the same opening can fall under the exemption, while enlarging an opening, changing operation, or a new-construction install brings the project into permit territory, where a Title 24 energy compliance form becomes part of the submittal. We confirm which side of that line your project lands on before we start, and handle the paperwork when it's needed.

Fire-zone glazing on hillside parcels

A large share of Lafayette sits in mapped Fire Hazard Severity Zones — mostly High, with a smaller Very High area on the wooded hillsides — and on designated parcels California's Wildland-Urban Interface building standards reach exterior glazing, commonly calling for tempered and/or multi-pane units on regulated openings. Whether that applies to your windows depends on your parcel's designation and whether the work is classed as a repair or an alteration, so it's worth pinning down early rather than at ordering. We check it against the current code with the City and County as part of scoping. (For the wall side of a fire-hardening project, see our Lafayette James Hardie siding page.)

What affects the cost

Every job is different, so we don't post prices. The drivers are the number and size of openings, the frame material and brand, retrofit versus new-construction, whether fire-zone tempered or multi-pane glazing is required on your parcel, the condition of the existing framing (rot repair adds scope), and access — upper-story and hillside openings take more setup.

Frequently asked questions

Do I need a permit to replace windows in Lafayette? It depends on the work. The city lists like-for-like ("in-kind") window replacements as exempt, while new or changed windows and skylights are not exempt and require a permit — with a Title 24 energy form as part of the submittal. We confirm which applies and handle the permitting when it's needed.

I'm on a hillside fire-zone lot — do my windows need tempered glass? Possibly. On designated High or Very High FHSZ parcels, WUI standards can require tempered and/or multi-pane glazing on regulated openings, depending on your parcel and whether the work is a repair or an alteration. We verify the current requirement before ordering.

Can new windows keep the look of my older Lafayette home? Yes. Frame material and profile can be matched to the original openings — clad-wood and specific vinyl or aluminum profiles all work depending on the house and the trim detail.

Retrofit or new-construction — which install do I need? Retrofit keeps the existing frame and is less disruptive; new-construction removes the window to the rough opening and is the right choice where there's rot or water damage and you want the flashing fully renewed. We assess the opening and recommend.

Get started

Get your Lafayette windows sized, specced, and installed right the first time. Request an estimate or call Bay Area Siding Company at (415) 619-5167. Doing the walls too? See Lafayette siding replacement, browse the project gallery, or explore our wider Contra Costa service area.