Fourplex Window Replacement — Triplex and 4-Unit Buildings, Doors Too
You own a triplex or fourplex, the windows are failing in every unit, and the job has to run around tenants, a shared stairwell and one front door.
Reply within one business day. Or call / text 763-204-2099.
Fourplex window replacement covers three- and four-unit buildings: JMB Builders measures every opening in every unit and the shared stairwell, orders one window and door spec for the building, and quotes it line by line, grouped by unit. Installs run one unit at a time, each opening closed the same day, shared stair kept clear. Twin Cities metro to St. Cloud. Priced per unit; send photos for a reply within one business day or book a free in-home estimate.
- Priced per unit, every opening listed
- One measure, one order for the building
- Shared stair and entry kept passable
A three- or four-unit building is still residential work in Minnesota, and it is a bigger job than a house or a duplex in one specific way: everybody shares the stair. The front entry, the stairwell windows, the back door to the laundry and the hallway are used by every tenant every day, so the order of work matters as much as the windows.
We walk the whole building once: each unit, the stairwell, the basement and the exterior on every side. Every opening gets a line on the quote with its unit, room, size, style and whether it goes in as an insert or full frame. Bedroom windows are checked for egress. The windows and doors go in one order, so frame color, glass and grilles match from unit 1 to unit 4.
On install days we finish one unit before starting the next, and the common areas get their own day so the stair is never blocked at the hours tenants leave and come home. Each opening is closed the same day it is opened. Floors in the path are covered, old units leave the site daily, and you have one number to call at JMB for the whole job.
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 tenants as your leases and Minnesota law require
- Which units or sides go first if the job is phased
- Where a trailer and the old windows can sit on site
- Any rental license or city inspection orders that name windows or doors
- Your decision on frame color, glass and grilles for the whole building
What JMB supplies
- One walk-through measure of every unit, the stairwell and the exterior
- A line-item quote by opening, grouped by unit
- Windows and doors ordered together through ABC Supply
- Unit-by-unit install, each opening closed the same day
- Bedroom windows checked and ordered to meet egress
- Drop cloths in the path, daily clean-up and haul-away
- Permit pulled when the city requires one
- Photos of each finished unit in your job folder
- A certificate of insurance and a W-9 on request
How it is priced: per unit
Quoted in writing from your photos, with a reply within one business day. What moves the number:
- Number of units and openings per unit
- Insert vs. full frame, opening by opening
- Stairwell windows over open stairs that need a work platform
- Second- and third-floor exterior access
- Shared entry, back and unit entry doors in the scope
- Exterior capping and interior trim scope
- Whole building at once vs. phased by unit or side
Send photos of each side of the building, the stairwell and one photo per window labeled by unit. The free in-home estimate firms it up. Paid by check or direct deposit.
How long it takes
Most units take one to two days once the windows are on site; the stairwell and shared doors take their own day. Lead time depends on the brand and is written on the quote.
How your project works
- 1
Walk the building
Every unit, the stairwell, basement and exterior measured in one visit. We note egress, rot and access for each opening.
- 2
Line-item quote
Each opening listed by unit with style, size and install method, so you can do the whole building or phase it by unit or by side.
- 3
One order
Windows and doors ordered together so every unit matches. Lead time depends on the brand and is written on the quote; tenant dates are set when delivery is known.
- 4
Unit by unit, then common areas
One unit finished before the next, each opening closed the same day. The stairwell and shared doors get their own day.
- 5
Photos and invoice
Photos of each unit go in your job folder. The invoice follows the quote, unit by unit.
Fourplex Window Replacement — Triplex and 4-Unit Buildings, Doors Too: questions, answered
Does a residential contractor license cover a fourplex in Minnesota?
Minnesota's residential building contractor license covers buildings built for one to four families, so a triplex or fourplex is residential work, and JMB Builders is licensed under BC809005. We also take buildings with five or more units. Those fall under the commercial building code, so before we bid we check the city's contractor licensing and permit rules and plan for fire-rated unit doors where the building needs them.
Do tenants have to move out to replace windows in a fourplex?
No. We work one unit at a time and close each opening the same day it is opened, so tenants stay. They clear a few feet in front of each window and keep pets out of the room we are in. You give the notice your lease and Minnesota law require; we give you the dates and rooms.
Can the stairwell windows in a 4-unit building be replaced too?
Yes. Landing and over-the-stair windows are measured with the units and replaced on their own day, from a work platform built over the stairs. Glass near stairs often has to be safety glass, and we order it where the code calls for it. The stair stays passable at the end of each day.
Can I replace windows in two units now and two later?
Yes. The quote lists every opening by unit, so you can sign for part of the building. The brand, series, color and grille pattern are written on the quote so the later units match. One order for the whole building usually costs less per window than two.
Should the doors be done with the windows on a fourplex?
Often, yes. The shared front and back entry doors, and any unit entry doors you want replaced, can go on the same order so colors and hardware match. Unit doors off a shared hallway can have code requirements of their own; your city's inspector decides, and we order what the permit calls for.
Do I need a permit to replace windows in a fourplex?
Many Twin Cities cities require one for window and door replacement, and rental buildings are inspected more often. When the job needs a permit, JMB pulls it and schedules the inspection with you so a unit can be opened up for it. Check your city's rental license rules too.
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 whole-house projects pages
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Based in Zimmerman, scheduling across the Twin Cities metro. Closest first: