Casing (Door and Window Trim) Takeoff
The trim around a door or window opening, counted in linear feet.
Quick Answer
Casing is the finish trim that frames a door or window opening and covers the gap between the jamb and the wall. Interior casing is taken off in linear feet per opening, per wall face. Exterior casing is the same trim outside and usually sits in the siding or exterior trim scope.
The Full Picture
Casing is the trim that surrounds the edge of an opening. It covers the joint between the jamb of the door or window and the finished wall. Interior casing is part of finish carpentry, and exterior casing, the same idea on the outside face, belongs to the exterior envelope. The two are often priced by different crews and sit in different spec sections, so the takeoff should keep them apart.
The unit is linear feet, counted opening by opening. A typical door is cased on both sides of the wall with two legs and a head, so one door needs three pieces per face. A window may be cased on three or four sides, depending on whether it has an apron and stool, and the schedule or the detail tells you which. Corners are miter cuts or butt joints with plinth blocks, which changes labor and piece counts. Count the openings from the door and window schedules, then confirm the trim profile and species in the finish schedule or the specifications, not from the plan view alone.
Many takeoffs go wrong by counting one side. Interior walls usually have casing on both faces, and a door between two finished rooms gets two sets. Openings with no door, such as cased openings between rooms, still take casing. Another trap is the casing style: painted MDF, stain-grade hardwood and PVC exterior trim are different materials with different unit costs even at the same LF.
Casing also touches accessibility. The U.S. Access Board guide says clear width is measured from the stop, so the jamb and stop set the clear opening, and casing is an outside finish. Confirm with the architect if thick trim or hardware crowds an adjacent wall at a tight accessible route.
Real Examples
Common Misconceptions
People assume: Casing and baseboard are the same trim package.
Actually: Casing frames openings, while baseboard runs along the floor. They can be the same profile family, but they are measured separately: casing per opening, baseboard by wall LF.
People assume: Each door needs one set of casing.
Actually: A door in an interior wall is usually cased on both faces, which doubles the LF. Check the wall type and the finish schedule to see whether both sides are finished.
Does MeltPlan Solve This?
Partially — adjacentCasing quantities begin with opening counts and sizes from the door and window schedules and plans, and MeltPlan's takeoff service covers that counting: AI pulls quantities from plans and US-based experienced estimators review and adjust them. Trim profile, grade and the number of finished faces stay with the estimator and the finish schedule.
Get door and window counts and trim LF pulled from your plans →Frequently Asked Questions
How do you calculate casing for a door?
Add two legs and one head for each finished face. Legs are about the door height, and the head is the door width plus the casing width at each end. Multiply by the number of faces, then by the number of doors, and add a cutting allowance.
What is exterior casing?
Exterior casing is trim around a window or door on the outside face of the wall. It is commonly part of the siding or exterior trim scope and is often wood, fiber cement, or PVC rather than the painted MDF common inside.
Is casing counted in linear feet or each?
Linear feet is the usual unit for the material. Some estimators count each opening as a unit, such as a trim kit, when a subcontractor prices per opening. Know which unit the quote uses before comparing bids.
Does casing affect door clear width?
Casing sits outside the jamb, so it does not set the clear opening. The U.S. Access Board guide measures the clear width from the stop to the face of the door open 90 degrees, so the jamb and door size control it.