Attic Window Replacement — Gable Windows, Vent or Egress Size
The little window at the top of the gable has a cracked pane, a rotted sill and a bird's nest behind it, or it is the only window in the attic bedroom you want to finish.
Reply within one business day. Or call / text 763-204-2099.
Attic window replacement is the gable window under the peak: a rotted single pane sash in an unfinished attic, or the one window in a finished attic at the egress size the code calls for. JMB Builders replaces attic windows across the Twin Cities metro, as a vent unit or a bedroom-size unit, sealed to a heated or unheated attic. Priced per window, quoted from photos or at a free in-home estimate, with a reply within one business day.
- Priced per window, one or both gables
- Vent unit unfinished, egress size when finished
- Sealed to a heated or unheated attic, as the house needs
Older Twin Cities houses have a small window at the top of each gable. It was there to vent the attic in summer and to light the space, and most are original: a single pane wood sash, sometimes a pair, with a sill that has been wet for sixty years. The paint is gone, the glazing is loose, the wood is soft, and squirrels or birds have found the gap. Nobody looks at it because nobody goes up there.
There are two very different jobs behind this one window. In an unfinished attic the window is part of the attic's ventilation and sits above the insulation, in cold space. It is replaced with a small unit that can stay cracked for air, or with a fixed unit if the roof has ridge and soffit vents, and it is sealed to the gable sheathing against rain and animals, not against heat loss. In a finished attic the window is in a heated room, so it is foamed and flashed like any bedroom window, and if the attic is a bedroom the unit has to give the clear opening the code calls for, which often means a bigger opening than the old sash.
Access is the other half. The gable peak is the highest point on the house. The window is usually replaced from inside the attic with a ladder or a lift outside only to cap the trim. Painting is quoted as a separate line — or leave it primed and caulked and paint it yourself.
Get a written quote for this job
Three photos and a sentence is enough: a reply within one business day, or ask for a free in-home estimate. Or text the photos to 763-204-2099.
What you supply
- Whether the attic is unfinished storage, finished space, or going to be finished
- Your pick of style and exterior color; most people match the windows below
- Photos of the gable from the ground, the window from inside the attic, and a close-up of the sill
- Clear access to the attic hatch or stairs on the day
What JMB supplies
- In-home measure of the opening and a look at the attic's insulation and venting
- The window, ordered to size, as a vent unit or an egress-size unit
- Old sash and frame out and hauled away, with the nest and debris behind it cleaned out
- Rot repair at the sill and the gable studs around the opening (quoted from photos)
- Flashing and sealing to the gable wall; foam and sill pan where the attic is heated
- A screen on an unfinished attic vent unit so animals stay out
- Interior trim in a finished attic, or a simple stop in an unfinished one
- Exterior capping or trim matched to the gable
- Photos of the finished window in your job folder
How it is priced: per window
Quoted in writing from your photos, with a reply within one business day. What moves the number:
- Unfinished attic vent unit vs. a finished-room window foamed and trimmed
- Enlarging the opening to the egress size the code calls for in an attic bedroom
- Rot in the sill and gable framing, common on original attic sashes
- Access: from inside the attic vs. a lift or ladder at the peak
- One gable window vs. both ends of the house
- Exterior color and grilles matched to the windows below
Send one photo of the gable from the ground, one of the window from inside the attic, and a close-up of the sill. Say whether the attic is finished.
How long it takes
One attic vent window: two to three hours. A finished attic bedroom window with the opening enlarged for egress: one day. Both gables in the same trip.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized reply within one business day. Prefer a look in person? A free in-home estimate is always an option.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Situations and options
Vent window in an unfinished attic
A small awning or slider with a screen, set in the old opening and sealed to the sheathing. Stays cracked in summer to move air through the attic, shuts for winter. Sized to the old sash so the siding is untouched.
Fixed unit in a vented attic
Where the roof already has ridge and soffit vents, the gable window can be a fixed unit for light only, which is cheaper and never leaks air or lets anything in.
Finished attic bedroom window
A casement sized to give the clear opening the code calls for, foamed and flashed into a heated wall, trimmed inside to match the room. Often the opening is widened or lowered, which is framing work quoted with the window.
Both gables matched
The windows at each end of the attic replaced in the same trip, same unit, same color as the windows below, so the house looks finished from the street.
Attic Window Replacement — Gable Windows, Vent or Egress Size: questions, answered
Should an attic window be replaced or just boarded over?
Replaced, in most cases. An unfinished attic in Minnesota needs to move air in summer, and a small operable window at each gable is part of how older houses do that. Boarding it over looks bad from the street and traps heat. A small vent unit with a screen costs little more than the patching and keeps the house looking like itself.
Does a finished attic bedroom need an egress window?
Yes. A bedroom in the attic needs a window that gives the clear opening the code calls for, with the sill at a height a person can climb out of. Most original attic gable windows are too small. Replacing it means a bigger unit and often a wider or lower opening, which is framing work in the gable wall and is quoted with the window.
How do you get a window into the top of the gable?
Mostly from inside the attic. The old sash and frame come out from inside, the opening is repaired and the new unit is set from inside and screwed through the frame. The exterior trim or capping is finished from a ladder or a lift set at the peak. On a tall two-story gable the lift is the safe way, and it is part of the quote.
Why is the sill under my attic window rotted when nothing else is?
Nobody paints it. The attic window is the highest window on the house, so it was skipped on every paint job for decades, and the glazing fell out of the sash so rain ran straight into the wood. The sill and the bottom of the gable studs are checked when the old unit comes out and repaired before the new one goes in.
How do you keep birds and squirrels out of the attic after the window is replaced?
The old gaps around the frame are what let them in. The new unit is sealed to the sheathing on all four sides, an operable vent unit gets a screen, and any other holes in the gable near the window are closed while we are there. The nest and droppings behind the old window are cleaned out before the new unit goes in.
Does an attic window in an unheated attic need insulated glass?
Not for heat, because the attic is outside the heated part of the house and the insulation is on the attic floor. A standard insulated unit is still used because that is what the suppliers make and it holds up better than single glazing. Where the attic is finished and heated, the window is picked and sealed like any bedroom window.
Recent JMB work, from our job log
59 installs recorded across 30 Twin Cities communities since Dec 2025. Window and door installs for homeowners and the builders we work with. Counts come straight from our job log; no customer names.
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Read morePage reviewed October 10, 2026 · JMB Builders LLC, MN license BC809005 · All windows pages
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