Window replacement in Denver in 2026: the answer starts with your address

Denver's own rule, word for word

Most pages answer the permit question for "Denver" as if the metro were one city. It is not, and Denver's own answer is precise enough to quote. The 2025 Denver Building Code, the only code accepted for applications since 1 January 2026, lists the work that needs no permit. Item 24 of section 105.2 covers exactly this job: "replacement of windows and doors with no structural alterations and no change in size of opening in one- and two-family dwellings and townhouse units."

What the scope line means for your house

The exemption is not citywide blanket coverage: it names the building class (one- and two-family dwellings and townhouse units), and it names the job (same opening, no structural change). Enlarge the opening, touch the frame structurally, or change an egress window's effective size, and you have left item 24 and entered permit territory. Two named exceptions sit right under it: a designated preservation structure or a historic district needs a permit plus preservation approval, and a replacement window in a hazardous location follows the safety glazing rules of the residential code.

Historic Denver plays by a stricter book

Inside a designated historic district the exemption does not apply at all. The West Highland association's owners manual states it plainly: permits are required for window replacement, all of it, with Landmark Preservation review before work begins. If your block looks old enough to have a plaque, check the district map before you assume item 24 is yours.

The metro permit map, with quotes

Cross one municipal boundary and the answer flips. Colorado has no statewide building code for this and no state general contractor license, so every jurisdiction writes its own page. We read them on 17 October 2026 and marked each by how solid the document is: a code section beats a web page, a web page beats silence, and silence is reported as silence rather than filled in.

Two rules that survive every row

Enlarging an opening or changing an egress window's dimensions needs a permit everywhere on the map, exempt row or not. And the answer belongs in the quote: a contractor who writes your address's answer down owns it, while a contractor who waves the question off owns nothing. The suburb cards below compress the same table for the driveway conversation.

Glass for a Front Range winter

ENERGY STAR splits the country into four climate zones, and Denver sits in North-Central, where the Version 7 criteria cap a certified window at U-factor 0.25 and SHGC 0.40 as whole-unit NFRC values. The U-factor is the number that tightened in 2023, so a unit that carried the label on an older display may not pass today. The 0.40 solar cap is loose on purpose: in a heating-led climate you want January sun working for the south rooms, while the west walls get deliberately lower values so August evenings stay livable.

Altitude is the quiet third input

At 5,280 feet, ultraviolet load is stronger and the day-night temperature swing wider than in the cities window marketing is usually written for. The metro's working baseline is a low-E double-pane with argon fill; triple-pane earns its premium on north elevations and in bedrooms where cold glass is the comfort complaint, not the energy one.

Read the NFRC label, whole unit, on the quote

Whatever the package, the numbers that matter belong to the whole unit, not the center of the glass, and they belong on the quote itself: U-factor and SHGC as the NFRC label certifies them, because that is also what the energy code reads. In a windy February, air leakage counts as much as either of them: the certified cap is 0.30 cfm per square foot, and premium frames test under half of that.

Hail season and the insurance route

The Front Range is one of the country's reliable hail corridors, with a season that runs roughly May through September. That makes hail a design input here rather than bad luck. On the product side, laminated or impact-rated glass on the most exposed walls is the answer many owners pick, and the paperwork from a rated install is useful later. On the money side, hail damage is a sudden, dated event, which is exactly the kind of event homeowners insurance is built for; worn-out windows are maintenance and stay yours.

If a storm just hit your house

Sequence beats speed. Date the storm, photograph every damaged sash, frame and screen before anything is cleaned up, and have the damage described in writing with the window locations. The full claim route, including what adjusters ask for and where window claims stall, is on our insurance and window replacement page.

The money: drivers, and what is not subsidized

A Denver quote moves on five drivers: how many openings, insert versus full-frame, the glass package, second-story access, and lead-safe handling in the metro's many pre-1978 houses. Shape taxes sit on top: bow window replacement cost and large window replacement cost run at the top of the per-window range because of unit size and glass area, a standard casement window replacement cost tracks the base rate, and double pane window replacement cost is the baseline every package is measured against. For the measured arithmetic, per-window labor hours and whole-house math, see our installation cost guide; the written, itemized quote is the only number that binds your house.

No Xcel rebate, no federal credit, and what that quote line really is

Read Xcel Energy's 2026 Colorado rebate list line by line and you find heat pumps, attic and wall insulation, air sealing and energy audits. Window units are not on it; the nearest honest use of the program is the 60 percent rebate on a pre-and-post energy audit, capped at $100 to $200, which documents what your windows actually do. The federal 25C credit for energy-efficient windows was repealed for anything installed after 31 December 2025. So when a quote shows an "energy rebate" line, ask which program it names: the honest answers are a whole-house insulation or sealing measure, or a Boulder County energy program tier for income-qualified homes, and everything else is a marketing discount wearing a rebate's clothes.

The calendar, and repair versus replace

Why winter is a schedule play, not a price play

Is it cheaper to replace windows in the winter here? Neither the product nor the labor rate moves with the season. What moves is the calendar: Denver winters are dry and sunny between fronts, each opening stays open for a short planned interval and is sealed the same day, so a January project is routine rather than risky. Hail season fills books with storm work from May through September, which makes that the slow season for planned replacements even though it is the pleasant one to stand outside in. Broken glass or a dead seal outranks the calendar and should not wait for it.

Test before you quote: what repairs cost versus what replacements cost

Fogged insulated glass, tired weatherstripping and tired hardware are repairable at stated prices well under replacement, and a good share of the metro's draft complaints end there. Rotted frames, single-pane glass and crooked installations are not repairs. The signal-by-signal map, with five-minute tests for each, is on our when to replace windows page, and the leak-chasing half of the question is on the drafty windows page. Run them before the first quote, because a company that sells replacements will rarely run them for you.

Choosing a company without a state license to check

Colorado has no statewide general contractor license, which moves verification from the state to the municipality and to documents. Denver licenses contractors through its Community Planning and Development department; other cities register them. Whether you typed window replacement companies near me into a search box or asked the neighbor whose house just got done, the list mixes national brands, Denver-local shops and big-box programs, and the same five checks filter all of them:

1. A written permit answer that names your city or county, from the map above.
2. Colorado Secretary of State registration, active and in good standing, checked by you in two minutes.
3. Workers' compensation verified in the state's public coverage system, not a certificate photo.
4. NFRC whole-unit U-factor and SHGC values printed on the quote for the exact unit.
5. An exclusions line that says what the price does not cover: rot repair, lead-safe work, permit fees, disposal.

National brands, local shops, big-box crews

On the store question people actually ask: yes, Lowe's sells window replacement and Costco runs a program, and both fulfill through subcontracted local crews, which means the checks apply to whoever shows up at your door rather than the logo on the receipt. National window brands and Denver-local manufacturers install across the metro on the same terms. And if a quote arrives after a hail storm with a signature deadline attached, the deadline is the tell, not the discount.

What we read, and how

The one record that turns a claim into a document

This page is built on primary reads, dated 17 October 2026: the official 2025 Denver Building Code PDF, where section 105.2 item 24 exempts same-size window and door replacement in one- and two-family dwellings and townhouse units, quoted word for word; the West Highland historic district owners manual; Boulder's permit page, which does not state the swap answer and is reported that way, while its Landmark Alteration Certificate requirement for landmark homes is stated; Boulder County's alterations list; Adams County's exempt-work list; Arvada's city page at arvadaco.gov/525, which requires permits for residential replacement windows in the city's own words; and one live public permit record in Arvada's eTRAKiT, MISC24-00707, subtype WINDOWS, "replace windows like for like", finalized December 2024 at a job value of $6,514. For the money section: Xcel Energy's 2026 Colorado rebate list read line by line, and the repeal date of the federal 25C window credit. For the glass section: ENERGY STAR Version 7 criteria by climate zone. Cities whose pages do not state the answer are marked as such rather than guessed.

Common questions, Denver edition