Apartment Window Interior Trim Replacement — Sills, Returns, Casing
New windows are going in across the building, and the inside of every opening needs a finish that looks the same in every unit and survives the next ten turnovers.
Reply within one business day. Or call / text 763-204-2099.
Apartment window interior trim replacement is the inside finish on each new window: drywall returns or wood jamb extensions, a sill that holds up to tenants and condensation, and casing in one profile through every unit. JMB Builders does it on apartment buildings across the Twin Cities metro and north to St. Cloud, priced per opening with painting as its own line. Send photos for a reply within one business day, or book a free in-home estimate and walkthrough.
- Priced per opening, painting a separate line
- One trim detail across every unit
- Sill material picked for rentals
When windows are replaced across an apartment building, the inside of each opening is where tenants notice the job. An insert window leaves the old stool and casing to be patched or covered; a full-frame window leaves raw jambs and a torn drywall edge. Either way, every opening needs a finish, and on a building of fifty or a hundred windows the owner wants one detail repeated, not one per unit.
The decision that matters most is the sill. Rental sills take plants, wet towels, condensation running off the glass and the occasional cigarette. A painted pine stool swells at the ends and peels within a few turnovers. We price a moisture-resistant sill, such as a PVC or solid-surface stool, against paint-grade wood, so you can pick what your maintenance budget can live with.
We set the detail with you on the first unit: drywall return or wood jamb, sill material, casing width and profile. Then it repeats unit by unit. The quote lists each opening, so the trim can ride with the window order or be done later as its own phase. Painting is quoted as a separate line, or the trim is left primed and caulked for your painter.
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
- Access to each unit, and notice to residents as your lease and Minnesota law require
- Your choice of sill material and casing profile, set on the first unit
- Whether painting is on our quote or left for your painter
- Furniture moved back a few feet from each window, or tell us and we price moving it
What JMB supplies
- One in-person measure of every opening in every unit
- A line-item quote by opening, grouped by unit
- Drywall returns with corner bead, or wood jamb extensions, per the chosen detail
- New sill (stool) and apron, or a picture-frame casing with no stool
- Casing in one profile through the building, nailed, filled and caulked
- Drop cloths at each window and daily clean-up
- Photos of each finished unit in your job folder
- Painting quoted as a separate line when you want it
How it is priced: per opening
Quoted in writing from your photos, with a reply within one business day. What moves the number:
- Drywall returns vs. wood jamb extensions with casing
- Sill material: paint-grade wood vs. PVC or solid-surface
- Wall depth, which sets the jamb and sill width
- Insert windows with old trim to cover vs. full-frame openings with raw edges
- Water-damaged drywall or framing found under the old sill
- Number of openings and units done in one run
- Painting the trim, quoted as its own line
Send a photo of one typical window inside, close enough to see the sill and the wall depth, plus the window count per unit.
How long it takes
Interior trim follows the window install in each unit, typically within the same one to two working days per unit. A trim-only phase is scheduled unit by unit around residents.
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
Drywall returns, no casing
Drywall wrapped into the opening with corner bead and a sill at the bottom. Clean and modern, nothing for tenants to snag, but a dented corner is a drywall patch, not a trim swap.
Wood jambs and casing
Jamb extensions to the wall face with casing around. A dent or a pet scratch is one piece of casing replaced, which suits rentals that turn over often.
Moisture-resistant sills
A PVC or solid-surface stool where condensation, plants and wet towels end up. Priced against a paint-grade wood stool on the quote so you can compare.
Picture-frame casing
Casing on all four sides and no stool. Fewer parts, nothing to set things on, and the same piece of casing stocked for every window in the building.
Apartment Window Interior Trim Replacement — Sills, Returns, Casing: questions, answered
What is the best window sill material for apartments?
For rentals, a moisture-resistant stool, such as PVC or solid-surface, holds up better than painted pine where condensation and plants sit on the sill. Paint-grade wood costs less up front and can be the right call on a tight budget. We price both on the quote, opening by opening, so you can choose.
Should apartment windows get drywall returns or wood trim?
Drywall returns are cheaper per opening and look clean, but damage means drywall patching and paint. Wood jambs and casing cost more up front, and a damaged piece is swapped in minutes at turnover. Many owners pick drywall returns with a durable sill as a middle path.
Do you trim out windows another company installed in our building?
Yes. We trim out windows left bare by another installer, priced per opening. We look at a few units first to check that the frames sit square and the gaps are foamed, because trim cannot fix a window that was set badly.
Do you paint the new window trim in the units?
Painting is quoted as a separate line. Or the trim is left primed, filled and caulked for your painter or maintenance crew. On a turnover schedule, some owners have the painter do the whole unit at once.
How do you keep the trim the same in every unit?
We set the detail on the first unit with you: return type, sill material, casing width and profile. That spec is written on the quote and used in every unit after, so unit 1 and unit 40 match. Trim is ordered for the building, not unit by unit.
Do residents have to leave while the trim is done?
No. We work one unit at a time and the residents can stay; they keep a few feet clear in front of each window and pets out of the room. You send the entry notice your lease and Minnesota law require; we give you the dates and units.
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 apartment buildings pages
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