Replacing Interior Doors: What It Costs and What Matters

Interior doors are the finish detail nobody notices until they do. Flat 1970s hollow-cores in an otherwise updated home, doors that no longer latch, gaps you can see light through: swapping them is one of the highest-impact medium-sized projects we do, and one where coastal conditions complicate what looks like a simple job. Here is what actually matters.

Slab versus prehung: the first fork

A slab is just the door itself, hung on your existing frame and hinges. A prehung door arrives already mounted in a new frame, which replaces your old jamb entirely.

Slabs sound cheaper and sometimes are, but they require the existing frame to be square and sound, and every hinge mortise and latch bore must be cut to match. In older Wilmington homes, frames that have settled and swollen through decades of humidity are rarely square, so a prehung unit often produces a better door for similar total labor. Our rule of thumb: matching one damaged door in a good frame, use a slab; replacing doors through the house, go prehung.

Hollow core versus solid core

Hollow-core doors are light, cheap, and sound like drums. Solid-core doors, engineered wood fill inside a molded skin, cost more per door but swing with a satisfying weight, block noticeably more sound, and take abuse better. You do not have to choose one for the whole house: our most common spec is solid core on bedrooms and baths, where sound privacy matters, and hollow core on closets and pantries. Guests will not spot the difference; your ears will.

The coastal wrinkle: humidity and doors

Doors move with moisture, and coastal humidity gives them plenty. Two practical consequences:

First, material choice matters. Molded composite and MDF doors are dimensionally stable and paint beautifully, but MDF swells badly if it wicks standing water, so baths and laundry rooms want every edge sealed, including the top and bottom, the two edges painters routinely skip. Solid wood doors look wonderful and move the most; they need honest seasonal expectations.

Second, fit matters. A door gapped tight in a dry January will bind in an August swamp week. We hang doors with coastal reveal tolerances, and we seal all six sides before the final hang. Doors that stick every summer were almost always installed, or painted, wrong.

What it costs

Interior door replacement typically lands in the $300 to $3,000 per opening range all-in, and that spread is honest. A painted hollow-core slab into a sound frame sits at the bottom. A solid-core prehung with new casing, hardware, and paint lands mid-range. Structural changes, widening an opening for accessibility, converting to a pocket door, or reworking a load path above the door, reach the top. Multiply by a whole house of doors and it becomes a real project worth pricing properly rather than door by door on weekends.

Details that separate a good job from a fast one

Consistent reveals around every door. Hinges set flush, not proud. Doors that latch with a soft click, not a slam. Casing joints that stay tight through a humid summer. Hardware heights consistent through the house. None of this is difficult; all of it takes caring about the second hour of each door, which is exactly the hour a rushed job skips.

When we quote door work, the written custom scope specifies every opening: slab or prehung, core type, hardware, casing, paint, and sealing, before you get a firm number. If your doors are due, from one stubborn bathroom door to the whole house, request a free written estimate at /estimate and we will count the openings with you.