Replacement windows

Replacement windows, measured and installed right.

We replace old, drafty, and fogged windows with energy-efficient Low-E windows, sized to each opening and installed by our crews. Based in St. George, serving homes across Utah and Wyoming.

Get a free quote St. George homeowners

When to replace

Signs it's time for new windows

Windows rarely fail all at once. These are the problems we hear about most.

Fogged glass

Moisture between the panes means the seal has failed. The insulating gas is gone and the glass can't be wiped clean.

Hot or drafty rooms

A room that's always warmer or colder than the rest of the house often points to old glass, worn seals, or leaky frames.

Hard to open or lock

Sashes that stick, won't stay up, or don't latch are a comfort problem and a safety problem.

Old aluminum frames

Metal frames conduct heat and cold straight into the house and often sweat with condensation in winter.

Faded floors and furniture

Older glass lets through the UV light that bleaches wood, fabric, and art near the window.

Street and wind noise

Single-pane or poorly sealed windows let in far more outside noise than a modern insulated unit.

White double-hung replacement window installed on a home

Styles we install

A style for every opening

We match the window to how the room is used: what needs to open, what needs a clear view, and what needs to ventilate.

Single-hung and double-hung: the classic up-and-down window; double-hung sashes tilt in for easy cleaning
Sliders: two- and three-panel windows that glide sideways, ideal for wide openings
Picture windows: fixed glass for the biggest, cleanest view
Casement: side-hinged windows that seal tight and open fully for airflow
Specialty shapes: arches, circle tops, and custom shapes to match existing openings

See the full lineup on our products page.

Dark-framed casement window with Low-E glass and a mountain view

Glass & frames

What makes a window efficient

The glass does most of the work. Every window we install is insulated, dual-pane glass with a Low-E coating, and we offer upgraded glass packages for sun-facing walls and large openings.

Dual-pane Low-E glass standard, with upgraded and triple-pane packages on select lines
Tempered safety glass where building code requires it, such as near doors and floors
Privacy glass options for bathrooms and street-facing rooms
Multi-chamber frames for insulation and strength
White, neutral, and dark exterior colors to match your home

Every window carries an NFRC label. Lower U-factor means less heat escapes in winter; lower SHGC means less of the sun's heat gets in during summer.

Installation

How we install

Good windows installed badly still leak. Installation is where a replacement succeeds or fails, so we plan it opening by opening.

Measure every opening

We take precise measurements at your free in-home consultation. Every window is ordered to fit.

Plan for your exterior

Stucco, brick, siding, and stone each need a different approach. We plan the install around the wall so it seals properly and looks finished.

Clean removal

We protect floors and furniture, remove the old units, and haul them away.

Seal, finish, walk through

Openings are sealed and finished, then we walk every window with you before we leave.

Your windows carry a manufacturer warranty, and our installation is backed by a one-year workmanship warranty. Read more about our process.

Questions

Replacement window FAQ

How long does a window replacement take?

Most homes are done in a day or two. Larger homes or special-order shapes can take longer, and we'll tell you what to expect when we quote.

How much do replacement windows cost?

It depends on the number of openings, their sizes, the window style, the glass package, and the color. We don't guess over the phone. The free in-home quote gives you an exact price with the options laid out, and the quote you get is the price you pay.

What does Low-E glass do?

Low-E (low-emissivity) glass has a microscopically thin coating that reflects heat. In summer it helps keep the sun's heat outside; in winter it helps keep your heat inside. It also cuts the UV light that fades floors and furniture.

How do I compare windows from different companies?

Look at the NFRC label. U-factor measures how well a window keeps heat from escaping (lower is better). Solar Heat Gain Coefficient (SHGC) measures how much of the sun's heat gets through (lower keeps a house cooler). Compare those numbers, not marketing names.

Do you serve my area?

We're based in St. George and install across Utah and in Wyoming. Tell us your city on the quote form and we'll confirm.

Are you licensed?

Yes. Mountaintop Windows & Exteriors, LLC is a licensed and insured Utah general building contractor, license #14309836-5501.