Pricing reviewed October 2026
A transom window typically costs $334 to $711 installed, with a national average of about $459, according to Modernize (as of Oct 27, 2026). Modernize puts the window itself at roughly $249–$531 and installation at about $70–$150. Wood frames can add about 50%, and cutting a brand-new opening into a load-bearing wall adds framing work on top of those figures.
A transom is the glass panel above a door or another window. It's sometimes called an "above-door window" or a transom light. It is defined by where it sits rather than by how it opens: most modern transoms are fixed, although operable ones exist. This guide covers what a transom costs on its own, which choices move the price, and the code question you should ask before you order one. For standard window styles such as double-hung, casement and sliding, see our window cost by type guide.
Transom window cost at a glance
| Item | Typical cost | Source (as of Oct 27, 2026) |
|---|---|---|
| Transom window, installed | $334 – $711 (avg. $459) | Modernize |
| Window unit only | $249 – $531 | Modernize |
| Professional installation | $70 – $150 per window | Modernize |
| General window-replacement labor (all styles) | $100 – $300 per window; $600+ for complex jobs | Angi |
| Wood frame vs. vinyl | About 50% more | Modernize |
| For comparison: single-hung / double-hung | $397 – $847 / $429 – $915 | Modernize |
| For comparison: windows with tempered glass (any style) | $200 – $700 per window | Angi |
The two labor figures don't match. Modernize's $70–$150 is specific to transoms, which are usually small and fixed. Angi's $100–$300 covers window replacement in general. If your transom goes into an existing rough opening, expect labor near the low end. If an installer has to cut and frame a new opening, the job behaves more like a small remodel, and neither figure covers the carpentry, drywall and paint.
What drives transom window cost
New opening or replacement
This is the biggest swing. Swapping the glass or sash in an existing transom is a simple window job. Adding a transom where there wasn't one is different. Modernize says it means cutting away a section of wall and removing the cladding, insulation and framing. In a load-bearing wall, the framing has to be reinforced. Modernize also says a transom needs a ceiling height of at least eight feet to fit above a door. Get the header and framing priced as a separate line on the quote.
Size and shape
A transom's width usually matches the door or window below it, and above a front door it often spans the sidelights too. Rectangular and square transoms are the simplest to make. Arched, semi-arched and fanlight shapes are specialty units and cost more to build and trim.
Glass
Clear glass is the usual choice. Frosted, tinted and stained glass cost more, and stained glass is the priciest of the decorative options (Modernize). On an exterior transom, insulated double-pane glass costs more than single-pane but performs far better. Modernize notes that clear single-pane transoms may not match the energy performance of double- or triple-pane windows.
Frame material
Vinyl, wood and aluminum are the common frames. Vinyl is the budget option, and wood adds roughly half again to the price (Modernize). On a front-door transom, many owners match the frame to the entry door system rather than to the other windows.
Fixed or operable
Most transoms today are fixed and mainly decorative. Operable transoms, with a crank or remote opener, are still made and add hardware cost. They also add cleaning effort, because the window sits high.
Safety glazing
Glass near doors is regulated. Under the 2021 International Residential Code, glazing in a panel next to a door counts as a "hazardous location" when two things are true. First, its bottom exposed edge is less than 60 inches above the floor. Second, it is within 24 inches of either side of the door in the plane of the door (IRC R308.4.2, quoted by Boulder County's building division, as of Oct 27, 2026). Glass in the door itself is always a hazardous location (R308.4.1). Hazardous locations need safety glazing, usually tempered or laminated glass. A transom whose bottom edge is 60 inches or more above the floor doesn't meet that "adjacent to a door" test. Low transoms over windows, sidelight-and-transom units, and local code amendments can change the answer, so ask your installer or building department before ordering.
Pros and cons of transom windows
| Pros | Cons |
|---|---|
| Brings daylight into entries and hallways, even when the main window's blinds are closed | Adding one to an existing wall can need structural reinforcement |
| Light without loss of privacy, because of the high placement | Interior transoms with clear glass can let people see between rooms |
| Usually cheaper than a standard single- or double-hung window (Modernize) | Clear single-pane units perform poorly on energy |
| Adds architectural character (fanlights, stained glass, craftsman grids) | Hard to reach for cleaning; decorative glass needs care |
Who a transom window is for
- Dark entryways. A transom over the front door, often with sidelights, is the classic fix.
- Interior hallways and baths. Interior transoms move borrowed light between rooms. Choose frosted glass where privacy matters.
- Period homes. Modernize suggests letting the architecture guide the shape: fanlights for Victorian, colonial revival and southern styles, patterned glass for craftsman, and plain rectangles for modern homes.
- Not ideal for rooms with ceilings under about eight feet, or where the wall can't take a new header without major work.
How to get an accurate transom quote
- Say whether the opening exists or must be created, and whether the wall is load-bearing.
- Specify the shape, the glass (insulated, tempered or laminated, decorative) and the frame material, so quotes are comparable.
- Ask for framing, drywall, exterior trim and paint as separate lines.
- Ask whether a permit is needed. A new opening usually changes the structure.
- Compare at least three written quotes. Our guide to comparing window quotes explains what to check.
Pricing the rest of the house too? See window cost by frame material. For other specialty windows, see jalousie window cost and impact-resistant window cost.
Get a number for your exact windows with the window replacement cost calculator.
Check a contractor's license (HomeProFax)
Frequently asked questions
How much does a transom window cost?
Modernize puts a transom window at $334 to $711 installed, with a national average of about $459 (as of Oct 27, 2026): roughly $249–$531 for the unit and $70–$150 for installation. Creating a new opening in a load-bearing wall costs extra.
Does a transom window need tempered glass?
Only if it is in a hazardous location. Under 2021 IRC R308.4.2, glazing next to a door needs safety glazing when its bottom edge is less than 60 inches above the floor and it is within 24 inches of the door. A transom set higher than that does not meet that test, but local amendments vary, so confirm with your building department.
Can you add a transom above an existing door?
Yes, but it means cutting into the wall above the door, removing cladding, insulation and framing, and reinforcing the framing if the wall is load-bearing. Modernize says the room needs a ceiling height of at least eight feet.
Is a transom window cheaper than a regular window?
Usually. Modernize lists transoms at $334–$711 versus $397–$847 for single-hung and $429–$915 for double-hung windows.
Are transom windows energy efficient?
It depends on the glass. Clear single-pane transoms can perform worse than double- or triple-pane windows. For exterior transoms, ask for insulated glass with an NFRC rating label.
Sources
- Modernize, "Transom Windows Buying Guide" (updated Aug 28, 2026); accessed Oct 27, 2026.
- Angi, "How Much Does Window Replacement Cost? [2026 Data]" (updated Oct 15, 2026); accessed Oct 27, 2026.
- Boulder County Building, "B30 Safety Glazing" (quotes 2021 IRC R308.4); accessed Oct 27, 2026.
Figures on this page come from the third-party cost guides, manufacturer documents and government sources linked inline and listed above, checked October 27, 2026. They are not from the WindowCostEstimate cost guide or our calculator pricing model. Prices and warranty terms change; confirm with the manufacturer and compare written quotes from local installers.