Front Door With Sidelights Replacement — Sidelites and Transom Units
An entry with sidelites and a transom is three or four pieces that have to act like one. Old unit out, sill rebuilt if it is soft, new unit set straight across the full width.
JMB Builders handles front door with sidelights replacement across the Twin Cities metro. We measure the whole opening, order a new door with sidelites (and a transom if you have one), pull the old unit, repair rot at the sill and framing, set the new unit in a sill pan with flashing, and trim it inside and out. Priced per door unit, quoted from photos within one business day.
- Priced per door unit, door included
- Door, sidelites and transom as one opening
- Sill pan and flashing on every unit
- Quote from photos in 1 business day
- Licensed MN contractor BC809005
A door with sidelites is a wide unit with a long sill, and a long sill is where water sits. The older ones often have single-pane sidelite glass, a threshold that has worn through at the door, and rot in the mull posts between the door and the sidelites. When one part goes, the fix is usually the whole unit, because the door, the sidelites and the sill share one frame.
We measure the full rough opening and the transom above it before anything is ordered. The new unit can match the old layout — one sidelite or two, full or half glass, transom or not — or change it. Dropping the sidelites means framing in the sides; adding them means a wider opening and a header sized for it. Either way the quote shows the door unit, the install and any framing as separate lines.
On install day the old unit comes out in one piece when it can, the sill framing gets checked and rebuilt where it is soft, and a sill pan goes down across the full width. The new unit is set level along that long sill, the door is squared to its own jamb so it latches, and a transom unit, if there is one, is set and flashed above it. Brickmould goes outside, casing inside. Painting is quoted as a separate line — or leave it primed and caulked and paint it yourself.
What you supply
- Your pick of door and sidelite style, glass and color
- Your choice of hardware finish, or your own lockset and deadbolt
- Photos of the whole entry from outside and inside, including the transom, and a close-up of the sill
- Paint color if you want the new trim painted — painting is quoted as a separate line
What JMB supplies
- Measurement of the full opening and the order for the door, sidelite and transom unit
- Removal and haul-away of the old unit and trim
- Rot repair at the sill, mull posts area and framing, quoted from the photos
- Full-width sill pan, flashing tape, foam, sealant, shims and fasteners
- Header check, and reframing when sidelites are added or removed
- Exterior brickmould and interior casing across the door, sidelites and transom
- Lockset, deadbolt and weatherstrip adjusted so the door latches and seals
- Photos of the finished entry in your job folder
How it is priced: per door
Quoted in writing from your photos within one business day. What moves the number:
- One sidelite vs. two, and whether there is a transom above
- The door and glass you choose: steel or fiberglass, clear, privacy or decorative glass
- Same layout vs. adding or removing sidelites, which means reframing the opening
- Rot at the long sill, the mull posts and the framing below
- Siding and exterior finish — vinyl, lap, stucco or brick — around a wide opening
- Interior trim across a wide entry, matched to existing casing or a standard profile
- Painting the door and trim, quoted as a separate line
Send a straight-on photo of the whole entry from outside and inside, with the transom in the frame, plus a close-up of the sill.
How long it takes
Door with sidelites in a sound opening: about a day on site. Add time for a transom, rot repair, or a layout change. 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
Same layout, new unit
Door and sidelites in the same sizes as the old ones. The simplest job: old unit out, sill checked, new unit set and flashed, trim put back or replaced.
Door with a transom
A transom above the door and sidelites is often a separate unit. We set the lower unit first, then the transom on top of it, flashed and trimmed as one opening.
Adding sidelites
Widening a single-door opening to take one or two sidelites. That means a longer header sized for the span and the siding and interior wall patched to the new width.
Removing sidelites
Going from a wide entry to a single door, often for privacy or a colder entry. We frame in the sides, insulate them, and patch siding and drywall to match.
Front Door With Sidelights Replacement — Sidelites and Transom Units: questions, answered
Can you replace just the sidelight glass instead of the whole door?
Sometimes, when the frame is solid and only a glass panel has failed or fogged. Most sidelite entries we see need more than glass: rot in the sill or mull posts, a worn threshold, or a door that no longer latches. We look at your photos and tell you whether glass alone makes sense before quoting a full unit.
Is a transom replaced with the door and sidelites?
Usually yes, when the transom is part of the same opening and the same age. It is often a separate unit sitting on top of the door frame, so we set the door and sidelites first, then the transom, and flash the head over both. If your transom glass is fine and you want to keep it, tell us and we quote around it.
Can I add sidelights to my existing front door opening?
Yes. The opening has to be widened, which means a new header sized for the wider span, new framing on the sides, and the siding and inside wall patched to the new width. We look at the wall from your photos first to see what is next to the door, such as a window, an outlet or a corner, before we quote it.
Why is the sill under my sidelights rotten?
A door with sidelites has a long sill, and older units were usually set right on the subfloor with no pan under them. Water that gets past the threshold or the sidelite glazing runs down and soaks the wood below. That is why the new unit goes in a full-width sill pan with flashing lapped at the sides and head.
Do you supply the door with sidelites or do I buy it?
We supply it. You pick the style and glass, we measure the full opening and order the unit so it fits, and the door is a line on the quote. If you already bought one, we install that too and price it as labor only.
Will the interior trim around the sidelights be replaced?
Yes. New casing goes around the door, the sidelites and the transom, either in a standard profile or matched to the other trim in the house. It goes in primed and caulked. 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.
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Read morePage reviewed September 26, 2026 · JMB Builders LLC, MN license BC809005 · All doors pages
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