Half Round Window Replacement — Arched, Round Top and Eyebrow Units
The half round over your front window or entry has fogged between the panes, or the frame is soft, and you are not sure an arch can even be replaced.
Reply within one business day. Or call / text 763-204-2099.
Half round window replacement means templating the arched opening, ordering a new half round, round top or eyebrow unit made to that radius, removing the old one, and setting the new unit with flashing bent to the curved head. JMB Builders replaces arched windows across the Twin Cities metro, on their own or with the window below them. Priced per window, quoted from photos, with a reply within one business day.
- Priced per window
- Opening templated, unit made to the radius
- Curved head flashed and capped
Half rounds sit over picture windows, patio doors and entries, mostly in houses built from the 1980s on. An eyebrow is a flatter arch, a segment of a circle rather than a half. A round top is a window whose own top is arched. Most are fixed glass. When the seal between the panes fails they fog, and because they are up high and curved they often get left that way.
An arched unit is made to the opening, not picked off a shelf. We measure the width, the leg height and the rise, and on an odd or flattened arch we make a template of the opening. The new unit is ordered to that shape, so the lead time is usually longer than for a rectangle. If the window below is being replaced too, the two are measured together and can be ordered mulled as one unit.
Outside, the curved head is where water gets in. The new unit is flashed with tape that will follow the curve, and the head is capped with aluminum bent to the radius or trimmed in PVC. Inside, the curved jamb and casing are covered on the arched window trim page. If only the glass has failed and the frame is sound, a new sealed glass unit may be the smaller fix.
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
- Photos of the arched window inside and out, with the window below it if there is one
- A photo with a tape measure across the bottom of the arch
- Your frame color and glass choices
What JMB supplies
- In-home measure of width, legs and rise, with a template on odd arches
- The new arched unit ordered to that shape, or mulled to the window below
- Old unit removed and hauled away
- Flashing at the sill and curved head, exterior capping or PVC trim bent to the arch
- Interior jamb and casing reset, or new curved trim quoted on its own line
- Painting quoted as a separate line — or leave it primed and paint it yourself
How it is priced: per window
Quoted in writing from your photos, with a reply within one business day. What moves the number:
- Arch shape: true half round, eyebrow or round top
- Size and height off the ground or floor
- Unit alone vs. replaced together with the window below
- Exterior finish: capping bent to the curve or PVC trim
- Interior trim reset vs. new curved casing
- Glass-only swap vs. whole unit
Send a straight-on photo of the arch and one with a tape across its bottom edge.
How long it takes
One arched unit: about half a day to a day once it arrives. Made-to-shape units take longer to arrive than standard windows.
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
Half round
A true half circle, usually fixed glass, over a picture window, door or pair of windows.
Eyebrow
A flatter arch, wider than it is tall. Templated on site because the curve varies from house to house.
Mulled with the window below
The arch and the window under it are replaced together and can be ordered joined into one unit, with one set of flashing.
Glass only
When the frame is sound and only the seal has failed, a new sealed glass unit cut to the arch can go into the old frame.
Half Round Window Replacement — Arched, Round Top and Eyebrow Units: questions, answered
Can you replace just the glass in a half round window?
Often, yes. If the frame is sound and only the seal between the panes failed, a new sealed glass unit is made to the arch and set in the old frame. If the frame is soft or leaking, the whole unit is the better fix.
How do you measure an arched window for replacement?
We measure the width across the bottom, the height of the straight legs if it has any, and the rise of the arch. On eyebrows and odd arches we make a template of the opening. The new unit is ordered to that shape.
Do half round windows take longer to get?
Usually, because each one is made to the opening's shape. We give you the expected date when the order is placed and schedule the install once the unit is here. The old window stays in until then.
Should I replace the arched window and the window below it together?
If both are old, yes. They are measured together, the glass and frame color match, and they can be ordered as one mulled unit with one set of flashing. If only the arch has failed, it can be done alone.
How is the curved top of an arched window flashed?
With flashing tape that stretches to follow the curve, lapped so water runs out over the window and not behind it. The head is then capped with aluminum bent to the radius or trimmed with PVC. The curve is where old arched windows usually leak.
What is an eyebrow window?
An eyebrow is a flatter arch, wider than it is tall, often over a picture window or set alone in a gable. It is replaced the same way as a half round, with the opening templated because the curve varies.
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 9, 2026 · JMB Builders LLC, MN license BC809005 · All windows pages
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Window Replacement & Installation near you
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