Las Vegas Window Guide: Heat, Energy Code, Rebates & HOAs

Desert heat and climate zones

The U.S. Department of Energy describes a hot-dry climate as a region with less than 20 inches of annual precipitation where the monthly average temperature stays above 45°F all year. Clark County is in IECC Climate Zone 3B, the dry part of the hot-dry climate. Clark County's code amendments treat areas of the county above 4,000 feet as Climate Zone 5B.

ENERGY STAR uses its own climate map for windows. Every Clark County ZIP code is in the ENERGY STAR South-Central zone, which includes Las Vegas, Henderson and North Las Vegas.

Sun, solar heat and UV

In a cooling-dominated climate, the sunlight coming through the glass is a big source of heat. The Solar Heat Gain Coefficient (SHGC) measures that: it's the ratio of solar heat entering through the window to the solar radiation hitting it. Lower numbers mean less solar heat.

The Department of Energy's Building America window guide explains that low-solar-gain low-e coatings, typically with an SHGC below 0.25, reduce solar heat gain while still letting visible light in. With these coatings, the direction a window faces matters much less for cooling. The same guide explains that low-e coatings strongly reflect long-wave infrared radiation, and that spectrally selective versions are designed to pass some wavelengths and reflect others. Ask any window professional what a given glass package does for heat, daylight and fading of furnishings, and ask for the product's ratings in writing.

ENERGY STAR certified windows in the South-Central zone must have:

U-factor of 0.28 or lower
SHGC of 0.23 or lower

The energy code for windows

Nevada's Governor's Office of Energy adopted the 2024 IECC, and Clark County adopted it with the Southern Nevada amendments by ordinance in July 2025. According to the Clark County Building Department, all new building permit applications from January 11, 2026 must show compliance with the 2024 IECC. The amendments were developed jointly by Southern Nevada jurisdictions including Clark County, Henderson, Las Vegas and North Las Vegas, and each jurisdiction adopts them on its own.

Requirement (Table R402.1.2, Climate Zone 3)	Maximum
Vertical window (fenestration) U-factor	0.30
Glazed vertical fenestration SHGC	0.25
Skylight U-factor	0.53
Skylight SHGC	0.28

Under the code, alterations and repairs to existing buildings follow the code's chapter on existing buildings rather than the new-construction rules. Whether a window replacement in your home needs a permit, and which requirements apply, is a question for the building department that serves your address.

Rebates and tax credits

Federal 25C tax credit has ended for new installs. The IRS says the Energy Efficient Home Improvement Credit can be claimed for improvements made through December 31, 2025. For windows placed in service in 2025, the credit was limited to $600 per year for exterior windows and skylights, and the windows had to meet ENERGY STAR Most Efficient requirements. If you installed qualifying windows in 2025, the IRS says to claim it on Form 5695 for the year they were installed.
NV Energy. NV Energy's 2026 Home Improvements Program rebate sheet lists duct sealing, duct insulation, and attic, wall and floor insulation. It doesn't include windows. See NV Energy's site for its current programs.
Nevada home energy rebates. The Governor's Office of Energy has federal funding for the Home Efficiency Rebates program, but its timeline lists the launch as pending federal review and program guidance.

We only list incentives we could confirm on official sites. If someone tells you about a window rebate, ask for the program's official page.

HOA approval and permits

Many valley neighborhoods are common-interest communities governed by Nevada Revised Statutes Chapter 116 and by each community's own governing documents. Before you order windows:

Read your community's CC&Rs and architectural guidelines for rules on window styles, frame colors, grid patterns and glass tint.
If changes to the outside of your home need approval, submit the request and get the decision in writing before ordering, since custom windows can be hard to return.
Ask your window professional who will handle the HOA submission and any permit, and what drawings or product sheets they'll provide.
Contact the building department for your address: Clark County, City of Las Vegas, Henderson or North Las Vegas.

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Sources

Sources checked November 15, 2026. Codes, rebates and tax rules change, so confirm details with the agency before you rely on them.

Las Vegas homeowner's guide to windows