Garden Window Installation Over a Kitchen Sink — Unit, Support, Roof
A flat window over the sink with no room for herbs, or an old garden window that leaks at the top. We put in a new garden unit that is supported and flashed so it stays dry.
JMB Builders does garden window installation over a kitchen sink across the Twin Cities metro. We measure the opening, order a garden window to fit it, remove the old flat window, set the new box unit on supports, flash the glass top and sides into the wall, seal it, and trim the inside and outside. Priced per window, quoted from photos within one business day.
- Priced per window, garden window supplied
- Supported, flashed and trimmed
- Replaces a flat window or old garden unit
- Licensed MN contractor BC809005
A garden window is a box that sticks out from the wall: glass on top, glass on the sides (often with small vent windows), and a shelf at the bottom. It usually goes over the kitchen sink, in the opening where a flat window was. It brings in light and gives you a shelf for plants.
Most garden window problems start at the top. The glass roof sheds water right at the wall, so the head has to be flashed into the housewrap and siding, not just caulked. The box also has weight hanging out past the wall, so it needs to be fastened into framing and supported underneath where the maker calls for it. Old garden windows that leak or sag usually missed one of those.
We measure the opening, order a unit sized to it, and install it with the head flashed, the base supported and the sides sealed. Inside, the jambs, shelf edge and casing are finished. For interior trim only on a garden window you already have, see our garden window trim page. Painting is quoted as a separate line — or leave it primed and caulked and paint it yourself.
What you supply
- Your pick of garden window size, frame color, glass and vent style
- Counter and sink area cleared, faucet clear of the opening
- Photos of the window inside and out and of the siding around it
What JMB supplies
- Measurement of the opening and the order for the garden window
- Removal and haul-away of the old flat window or garden unit
- Fastening into framing and support under the box where required
- Flashing tape and head flashing lapped into the wrap, plus sealant
- Siding reset or patched around the unit
- Interior jamb, shelf edge and casing trim
- Photos of the finished window in your job folder
How it is priced: per window
Quoted in writing from your photos within one business day. What moves the number:
- Garden window size and whether it has operating side vents
- Replacing a flat window vs. an old garden unit
- Siding type around the opening and how much has to come off
- Framing repair if the old unit leaked
- Interior trim: casing only vs. new jambs and a shelf edge
- Painting the interior trim, quoted as its own line
Send a photo from inside over the sink and one from outside with the siding around the window in view.
How long it takes
One garden window in a sound opening: most of a day on site. The unit is ordered after you approve the quote.
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 quote within one business day. We only come out to measure first when the job needs a tape measure — no pressure, no games.
- 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
Flat window to garden window
The flat kitchen window comes out and a garden window is set in the same opening. The rough opening is checked and adjusted if the unit calls for it.
Old garden window replaced
A leaking or fogged garden unit is removed, the framing is checked for water damage, and the new one goes in with proper head flashing.
Vented sides
Small casement or awning vents on the sides let air in over the sink. Fixed sides cost less and seal tighter.
Garden Window Installation Over a Kitchen Sink — Unit, Support, Roof: questions, answered
Can a garden window go in my existing kitchen window opening?
Usually. Garden windows are ordered to fit common rough opening sizes, and the flat window comes out and the new unit goes in the same hole. We measure the opening before ordering to confirm it.
Why does my garden window leak at the top?
The glass roof sheds water right where the box meets the wall. If the head was only caulked, not flashed into the housewrap and siding, water gets behind it. A new unit needs that head flashing done right.
Does a garden window need support underneath?
Many do, depending on the size and the maker's instructions. The box holds glass and plants past the face of the wall, so it is fastened into framing and supported where the maker calls for it.
Will my faucet hit a garden window?
A tall faucet can sit close to the shelf. Garden windows usually start at the same height as the old window sill, so we check the faucet height in the photos before ordering.
Do garden windows get condensation in winter?
They can, because the glass sticks out into the cold on three sides. Keeping indoor humidity reasonable and running the kitchen fan helps. Better glass reduces it too.
Do you trim the inside of the garden window?
Yes. We finish the jambs, the shelf edge and the casing so it looks built in. Painting is quoted as a separate line, or leave it primed and caulked and paint it yourself.
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 for the builders and dealers we sub for. Counts come straight from our job log; no customer names.
Get a written quote for this job
Three photos and a sentence is enough. You hear back within one business day. Or text the photos to 763-204-2099.
Related jobs we do
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Read morePage reviewed September 26, 2026 · JMB Builders LLC, MN license BC809005 · All windows pages
Where we work
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Based in Zimmerman, scheduling across the Twin Cities metro. Closest first: