Replace Six Panel Doors With Flat Panel Doors — Colonial to Modern
Every door in the house is the same hollow six-panel colonial from the builder, and the rest of the house has moved on.
Reply within one business day. Or call / text 763-204-2099.
To replace six panel doors with flat panel doors, the colonial molded doors come out and flush slabs or single flat-panel doors go in, either fitted into the same jambs with the hinge and bore locations matched, or as prehung units with new flat casing. JMB Builders supplies the doors and does the swap across the Twin Cities metro, usually a whole floor in a day. Priced per door, with a reply within one business day.
- Priced per door, flat doors supplied
- Slabs into your jambs or prehung with flat casing
- Hinge and bore locations matched to the old doors
Builders in the Twin Cities hung the molded six-panel hollow-core door in nearly every house from the mid-1980s through the 2000s. It was cheap, it was everywhere, and it dates a house now. The raised colonial profile fights flat kitchen cabinets, square casing and modern hardware. Swapping the doors for flush or flat-panel doors is the cheapest change that touches every room.
There are two ways to do it. If the jambs are square and the casing is staying, we fit flat slabs into the existing jambs: match the hinge mortises, bore the lockset at the same height, plane the edges to an even margin. The casing stays and the room is done in an hour. If the jambs are racked or the casing is coming off for a flat profile anyway, prehung flat-panel units with new jambs and casing are the cleaner route and let you square up openings that never were.
Flat doors come as flush slabs — a smooth face with no panel at all — or as a single flat recessed panel, which is a one-panel Shaker. Hollow core keeps the swap cheap; solid core makes the new doors feel like an upgrade and not just a change. We supply options such as Masonite, Jeld-Wen and Trimlite in primed or prefinished, and painting is quoted as its own line.
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
- Flush slab or single flat recessed panel, and one choice for the whole house
- Hollow core or solid core, room by room if you like
- Whether the existing casing stays or goes flat with new prehung units
- New hinge and lever finish, or we reuse your existing hinges and hardware
- Paint color if you want the doors painted — quoted as its own line
What JMB supplies
- Flat doors sized to each opening with the correct handing, as slabs or prehung units
- Removal and haul-away of the six-panel doors, and old jambs and casing on prehung swaps
- Hinge mortises and lockset bores matched to the existing jambs on slab swaps
- Edges planed to even margins; doors cut to clear carpet or new flooring
- Flat square-edge casing on prehung units, or your existing casing re-set
- Hardware fitted and doors adjusted to latch cleanly
- Painting of the new doors and casing when you want it, quoted as a separate line
- Photos of the finished doors in your job folder
How it is priced: per door
Quoted in writing from your photos, with a reply within one business day. What moves the number:
- Slabs fitted into existing jambs vs prehung units with new jambs and casing
- Flush slab vs one-panel flat door, and hollow vs solid core
- Primed vs factory-prefinished doors
- Odd sizes and out-of-square jambs that take extra fitting
- Reusing your hinges and levers vs new hardware in a new finish
- How many doors in one visit — the per-door price falls as the count rises
- Painting the doors and casing, quoted as a separate line
Send a photo of one door with its casing, a close-up of a hinge, and the total count. If any door is a bifold, bypass or pocket door, say so; those are priced on their own.
How long it takes
Slabs into existing jambs: six to eight doors in a day. Prehung swaps with new casing: four to six in a day. Doors are ordered after the quote is approved; primed stock sizes arrive quickly.
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
Flush slabs into existing jambs
Smooth flat doors fitted into the jambs you have. Hinges and bores matched, edges planed, casing untouched. The fastest and cheapest way to lose the colonial look across a whole house.
One-panel flat doors, prehung
A single flat recessed panel in a new jamb with flat square casing. For when the old jambs and casing are going anyway. Squares up openings the builder left out of plumb.
Solid core flush doors
The upgrade version. Heavy, quiet, dent-resistant flat doors in the bedroom and bathroom openings, hollow core on closets to keep the cost down. Same look, different feel in the hand.
Replace Six Panel Doors With Flat Panel Doors — Colonial to Modern: questions, answered
Can I replace six panel doors without replacing the frames?
Yes, when the jambs are square and sound. We fit flat slab doors into your existing jambs, mortise the hinges to match the old locations, bore the lockset at the same height and plane the edges for an even margin. The casing stays and the room is done in about an hour per door. If a jamb is racked or split we tell you, and that opening gets a prehung unit.
What is the difference between a flush door and a flat panel door?
A flush door is one smooth face with no panel at all. A flat panel door, often called a one-panel Shaker, has a flat recessed panel inside a flat frame of stiles and rails. Both read as modern next to a six-panel colonial. Flush is the plainer of the two and suits a minimal house; one-panel adds a shadow line and suits most remodels.
Will new flat doors fit the old hinge locations?
On a slab swap we mortise the new door to your jamb's hinge locations, so the hinges go back exactly where they were. Standard door sizes match, and most 1980s to 2000s houses used standard sizes. Where a jamb has a non-standard hinge spacing or an odd height, we fit the slab to it; that is the normal work of hanging a slab.
Should I do all the doors at once or a few at a time?
All at once if the budget allows. The per-door price drops as the count goes up because the setup, the order and the trip are shared, and the house looks finished instead of half-done. If you split it, do one whole floor at a time so no hallway shows both styles. Closet and bifold doors can follow later; they are priced separately.
Do I need new casing when I change to flat doors?
No. A flush or one-panel door looks fine against most existing casing, including colonial profiles, because the door is plain enough not to fight it. New flat casing is a style choice that goes with prehung swaps when the old casing is coming off anyway. If you are keeping the casing, slab swaps leave it untouched and unpainted.
Can I keep my existing door knobs on the new flat doors?
Yes, if they are in good shape. We bore the new door for a standard lockset and reuse your knobs and hinges. Most homeowners swap the hardware at the same time because the brass colonial knobs date the door as much as the panels did; a matte black or brushed nickel lever on a flat door finishes the change. New hardware is listed as its own line.
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 10, 2026 · JMB Builders LLC, MN license BC809005 · All doors pages
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