Interior Doors

Interior doors

Interior doors are the least documented door in the house

Every other door in this guide has at least one number behind it. Interior doors have none. No source we could reach publishes an installed price for one interior door, in any size, material or core. Zonda's Cost vs Value Report is the only study with a stated method that prices door projects nationally, and of the ten highest-return projects it publishes, three are doors¹. Not one of them is an interior door.

The nearest verified figure comes from the other end of the trade. NAHB's 2024 construction cost survey puts interior trims, doors and mirrors at $12,920 per new single-family home, 3.0% of a $428,215 total construction cost². That is a whole house, not one opening, and doors share the line with trim and mirrors. It is still the only number in this category that comes with a published method attached.

The other thing worth knowing before you call anyone is that this is not really door-contractor work. In California, the classification that covers making "cabinets, cases, sashes, doors, trims, nonbearing partitions" is C-6 cabinet, millwork and finish carpentry³, while the specialist door classification, D-28, is written around overhead and sliding assemblies⁴. For a hallway full of doors and casing, you want a trim carpenter.

Six things that decide what an interior door job becomes

With no published price to anchor against, the scope decisions are the whole conversation.

Slab or prehung

A slab is the door panel alone, hung on the jamb already sitting in the opening. A prehung unit brings its own frame, so the old jamb and the casing come out with it. Prehung is more work and more trim, and it is the honest answer when the existing frame has gone out of square.

Where the money actually sits

NAHB's builder survey puts interior trims, doors and mirrors at $12,920 in a new single-family home, 3.0% of construction cost, in a house averaging 2,647 finished square feet at about $162 per square foot². Doors share that line with trim and mirrors, so it cannot be read down to a price per door.

Two licences, one hallway

California splits this work in two. D-28 covers door assemblies including overhead and sliding types⁴, while C-6 cabinet, millwork and finish carpentry covers making cabinets, cases, sashes, doors, trims and nonbearing partitions³. For interior doors and casing a C-6 holder is squarely in scope, and both scopes are published on the state's own pages.

The permit question, usually the easy one

Austin's exempt-work list covers "replacing doors of the same size and operation", with the standing caveat that exempt work still has to comply with applicable codes⁵. Wake County, North Carolina takes the other route and rolls residential alterations into a flat $75 permit fee plus $0.25 per square foot of gross floor area⁶.

No credit was ever available

The federal Energy Efficient Home Improvement Credit reached exterior doors meeting ENERGY STAR requirements, at $250 per door and $500 total, and it closed to property placed in service after December 31, 2025⁷. Interior doors were never inside it. Nothing about an interior door swap is a tax event, before or after that date.

Make them price a door schedule

There is no published benchmark to test a lump sum against, so build the comparison yourself. List every opening: width, height, swing, hand, jamb depth, hollow or solid core, and whether casing is being replaced. Ask each bidder to price that list line by line. Two lump sums cannot be compared. Two schedules can.

Interior trims, doors and mirrors, new home$12,920, or 3.0% of construction cost

Installed price for one interior doorNot published by any source we could read

What does an interior door cost?

We cannot tell you, and we are not going to guess. That is a gap in the published record rather than a gap in this guide. The Cost vs Value study prices garage door replacement, steel entry door replacement and a fiberglass grand entrance, and nothing interior¹. The Census Bureau and HUD report a $2,800 median homeowner spend, but they bundle doors with windows and the figure cannot be split⁸. Retailer product pages, which are where per-door prices actually live, refused automated requests throughout this research. Anything you find online quoting a per-door installed price is coming from an aggregator that does not say how it got there.

What does exist is a builder's view of a whole house. NAHB puts interior trims, doors and mirrors at $12,920 per new single-family home, 3.0% of a $428,215 total construction cost, in a house averaging 2,647 finished square feet². Quote that number with its base attached: NAHB emailed a questionnaire to a representative sample of 4,000 home builders and, after outlier analysis, had 41 usable responses². Forty-one builders is a thin sample, and it describes new construction rather than a retrofit into an existing wall. It tells you the order of magnitude of doors and trim across a whole house. It does not price your hallway.

The only figures here are NAHB's 2024 construction cost survey, which is new construction built from 41 usable builder responses, and the Census and HUD 2023 American Housing Survey median that bundles doors with windows, and neither isolates the installed cost of a single interior door.

Hiring

How to hire for interior door work

1

Who does the work

Treat this as finish carpentry rather than door contracting. California says as much on its own licensing pages: C-6 cabinet, millwork and finish carpentry covers making doors, trims and nonbearing partitions³, while D-28 is written around overhead and sliding door assemblies⁴. For a hallway of prehung units and casing, a trim carpenter is the right call.

2

What pros will ask

How many openings. Slab or prehung for each. The width of the existing jamb, which is set by your wall build-up and is the detail that most often turns a one-day job into two. Swing direction and hand for every door. Hollow or solid core. Whether casing and base are being replaced, and whether flooring goes in before or after.

3

What to check before signing

That the quote is per opening rather than a lump sum, because you have no published benchmark to test a lump sum against. Who supplies the doors, and who paints them. Whether hardware is included or assumed. And in California, that nobody is stretching the small-job exemption: it stops at $1,000, and it applies only when the work also needs no building permit⁹.

Interior door questions, answered straight

How much does it cost to replace an interior door?

No source with a published method answers that, and this guide will not invent a figure. The national remodelling study that prices door projects covers garage, steel entry and fiberglass grand entrance work only¹. The federal household survey bundles doors with windows into one $2,800 median⁸. Retailer product pages blocked automated requests. The practical route is to write a door schedule listing every opening, then get two or three carpenters to price the same list, and compare those against each other.

What does NAHB's $12,920 figure actually cover?

It is line W of NAHB's 2024 single-family cost breakdown, headed interior trims, doors and mirrors, and it comes to 3.0% of a $428,215 total construction cost². Three things it is not: it is not per door, it is not doors alone, and it is not a remodel. It is also built on a small base. NAHB emailed 4,000 builders and got 41 usable responses after outlier analysis². Use it for scale and cite the sample size whenever you use it.

Do I need a permit to swap an interior door?

Usually not, but the answer belongs to your building department rather than to a guide. Austin lists replacing doors of the same size and operation as work exempt from a building permit, while stating that exempt work must still comply with applicable building codes and city ordinances⁵. Where a permit is required for alteration work, some jurisdictions price it flatly: Wake County, North Carolina charges $75 plus $0.25 per square foot of gross floor area for residential alterations⁶.

Is a prehung door worth the extra work over a slab?

It depends entirely on the jamb you already have. If the existing frame is square, plumb and undamaged, a slab keeps the casing and the paint line intact and is the smaller job. If the frame has racked, or the jamb width is wrong for your wall, a slab will fight you and never close properly. There is no verified price difference between the two approaches to weigh against that, so decide it on the condition of the opening.

Do I need a licensed contractor for interior doors?

In California, above a threshold, yes. Business and Professions Code 7048 exempts a project only when the aggregate contract price for labour, materials and everything else is under $1,000 and the work requires no building permit⁹. Two corrections worth carrying: the figure is $1,000, not the $500 many sites still print, and the no-permit condition is a second test, not a footnote. Splitting a job into sub-$1,000 contracts to get under the line is addressed directly in the statute⁹.

Sources

Where these facts came from

Every figure on this page was read out of the page linked below. We do not cite cost aggregators.

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