In a Morgan Hill summer, your windows are doing more work than you think. South County gets long stretches of clear, direct sun, and single-pane or tired dual-pane glass lets that heat pour straight into the house — the west-facing rooms bake in the afternoon and the AC never quite catches up. The right replacement window is really a glass decision first, and Bay Area Siding Company installs windows chosen to cut that solar heat gain while still holding up to the valley's wet winters. We're a Larkspur-based siding and window contractor, and we handle the whole job: measuring, glass and frame selection, permitting, removal, flashing and air-sealing, and the final walkthrough.

Ready to cool the house down? Request an estimate or call (415) 619-5167.

Why the glass package matters here more than most places

Two numbers describe how a window handles the sun. U-factor measures how well it insulates against heat flow; Solar Heat Gain Coefficient (SHGC) measures how much of the sun's heat it lets through. In a hot, sunny climate like Morgan Hill's, SHGC is the one homeowners feel — a lower SHGC with a good Low-E coating keeps summer heat out and rooms comfortable without overworking the AC. California's Title 24 energy code sets ceilings for both on replacement windows, but the exact values depend on the climate zone and the code cycle in effect, so rather than quote a number that may be stale, we confirm the current requirement at permit time and spec glass that meets it. If your west and south rooms are the problem, we'll steer the glass package accordingly.

The signs your windows are done

Replacement usually makes more sense than another repair when you notice:

• Afternoon rooms you can't cool and hot glass you can feel from across the room
• Fog or haze sealed between the panes — a blown dual-pane seal that can't be repaired, only replaced
• Sashes that stick, drop, or won't latch from swollen wood, paint, or worn balances
• Drafts and street noise that a modern insulated unit would quiet
• Rot or water staining at the sill or surround

Frame material and how the window goes in

Once the glass is settled, two more choices shape the job:

Frame material. Vinyl, fiberglass, aluminum-clad wood, and aluminum each balance cost, thermal performance, and looks differently. Morgan Hill's newer subdivisions often take a clean vinyl or fiberglass profile well, while downtown's older homes and custom Paradise Valley properties may call for a clad-wood look that respects the original openings.

Retrofit vs. new-construction. A retrofit (insert) install keeps the existing frame and is faster and less invasive — a good fit where the frames are sound. A new-construction (full-frame) install removes the window down to the rough framing so the flashing and water barrier at the opening can be fully renewed; it's the right call where there's rot or a history of leaks. We do both and recommend based on what we find at the opening.

Comparing brands? Start at our window hub, then read the lines: Anlin, Milgard, Andersen, Marvin, and Pella. We also install aluminum windows.

Permits, fire-edge glazing, and cost

Permits. Replacing windows is an alteration to your home, and the City of Morgan Hill's Building & Fire Prevention Division requires a building permit for that work; a Title 24 energy-compliance form for the new fenestration is part of the submittal. We prepare and carry it.

Fire-edge glazing. Morgan Hill's wildland edges — the eastern foothills above East Dunne Avenue, the ground below El Toro, and the semi-rural fringes — include parcels in High or Very High Fire Hazard Severity Zones, redrawn by the city's 2025 maps. Where a home carries that designation, Chapter 7A of the building code can govern exterior glazing, and altering an opening in the wildland-urban interface generally calls for multi-pane glazing with at least one tempered pane, among other requirements. Whether it applies turns on your specific parcel and whether the work is classed as a repair or an alteration, so we confirm the designation before ordering. On most flatland lots it isn't a factor.

Cost drivers. No online quote, because the price rides on the number and size of openings, the frame and brand, retrofit vs. full-frame, whether fire-zone tempered/multi-pane glazing is required, the condition of the framing behind the trim, and access on upper-story or hillside openings. We measure every opening before pricing.

Frequently asked questions

What glass should I choose for Morgan Hill's heat? A dual-pane, Low-E unit with a solar heat gain coefficient tuned for a hot, sunny climate. It's the biggest lever on afternoon comfort and cooling load, and we match it to your worst sun exposures within what Title 24 requires.

Do I need a permit to replace windows in Morgan Hill? Yes. The City treats window replacement as an alteration and requires a building permit with a Title 24 energy form for the new windows. We handle the permitting.

My home is on the east-side hills or a rural lot — will my windows need to be tempered? Possibly. In a designated fire-hazard zone, altering an opening in the wildland-urban interface generally requires multi-pane glazing with at least one tempered pane under Chapter 7A. The 2025 maps changed several boundaries, so we confirm your parcel's designation and scope before ordering.

Retrofit or full-frame — which is right for me? Retrofit keeps a sound existing frame and is less invasive; full-frame (new-construction) removes the unit to the framing so the flashing can be rebuilt, which is the better choice where there's rot or past water damage. We assess each opening and recommend.

Get started

Get your Morgan Hill windows sized, specced for the sun, and installed right. We work throughout South County and the wider South Bay; see finished work in our project gallery, and if you're doing the exterior too, we also handle Morgan Hill siding replacement and James Hardie siding. Call (415) 619-5167 or request an estimate.