2026 New Window Law… Are you Ready?
It all begins with an idea.
🏠 What Colorado’s 2026 Window Law Means for You
Dear Homeowner / Valued Customer,
Big changes are coming in Colorado building codes — especially when it comes to windows, doors, and skylights. As a local window‑ and restoration provider, we want you to be aware of what’s changing and how it can affect your next remodel or window replacement.
⚖️ What’s Changing: The New Rules
Starting January 1, 2026, new law under House Bill 23-1161 (and related energy‑code updates) requires that all new residential windows, doors, and skylights sold or leased in Colorado (in homes of three stories or less) meet higher energy‑efficiency standards.
The law enforces compliance by requiring products to meet either:
The “northern climate zone” criteria under ENERGY STAR for windows, doors, and skylights; or
Alternative energy‑efficiency standards established under the state’s code (§ 5 CCR 1004‑2(1.1)).
In practice, this means many standard windows currently on the market may no longer qualify — especially double‑pane units lacking upgraded thermal specs.
💡 What This Means for Homeowners & Renovators
Better energy efficiency and lower utility bills. The requirement encourages windows with improved insulation. (i.e. lower U‑factor, better glazing, gas fills, and warm-edge spacers), which reduces heat loss and can lower heating/cooling costs in Colorado’s climate.
Higher standard for materials. To comply, windows will likely need upgraded glazing, better spacers, and possibly thicker frames — in other words, higher‑performance products (not the lowest-cost builder-grade windows).
Wider use of efficient window systems. As a window installer in the Denver metro and Front Range areas, we expect demand to increase for premium windows designed for the “northern climate zone” — especially for homes exposed to Colorado’s winters and temperature swings.
Code compliance becomes mandatory. For anyone selling, leasing, or installing new windows, there’s no longer optional compliance: starting 2026, windows must meet the revised standards to be legally offered or installed.
✅ What We Recommend for You
If you’re thinking about replacing windows, remodeling, or installing new ones:
Request ENERGY STAR–rated windows built for the Northern climate zone and double‑check U‑factor/spec sheet.
Ask for warm-edge spacer systems, proper gas fills, and thermally efficient glazing.
Work with experienced installers familiar with the 2026 code — that’s us! As a window and restoration company serving the Denver metro and Colorado Front Range, we’ll make sure your project is code compliant and optimized for performance.
https://www.coloradosos.gov/CCR/GenerateRulePdf.do?ruleVersionId=12087
Warm Regards,
RPG Windows & Restoration