Trim, Specifically: What "Trim per Plans" Can Mean

If I had to pick one line in a custom home bid where the house you're picturing and the house the builder priced drift furthest apart, it would be trim. "Interior trim per plans" can describe two very different houses, and the drawings usually don't settle it.

Closing the gap between what you picture and what your builder priced gives trim one paragraph. It deserves a whole piece.

What's in a trim package

"Trim" covers more than most people think:

• Baseboard, and sometimes a shoe or quarter round at the floor
• Door and window casing
• Window stools and aprons, or a picture-frame return instead
• Head details over doors and windows
• Crown molding, if any
• Jamb extensions at windows and exterior doors
• Interior doors and their jambs
• Stair parts: treads, risers, skirts, nosing, railings
• Built-ins, open shelving, and any wood ceiling or wall treatment, depending on how the bid is split

Some of these may be in a different line of the bid, like doors or stairs. Find out where each one lives.

What drives the cost

Material. MDF, finger-jointed pine, poplar, and solid hardwood are all common, roughly in that order of cost. MDF paints beautifully and stays straight. If you want to stain it, you need a stain-grade species, which can be a hardwood or a softwood like knotty alder or fir.

Paint-grade or stain-grade. Stain-grade work shows every joint and every nail hole, so it's slower to install and needs better material. It's a bigger step up in cost than the material price alone suggests.

Profile and size. A flat 1x4 casing and a profiled casing with a back band and a head cap are different jobs. Baseboard height alone moves the number. A 3-1/4" base and a 7-1/4" base with shoe aren't the same material or the same labor.

Details. Reveals, mitered returns, built-up heads, and drywall returns instead of casing (which saves material but takes more drywall and finish work) all change the hours.

Jamb extensions. In the mountains, walls are often thicker than standard to hold more insulation. That means every window and exterior door needs an extension to bring the jamb flush with the drywall. On a house with a lot of glass, it's a real line item, and it's easy to miss.

The finish carpenter. Trim is one of the places where who does the work shows. A good finish carpenter costs more per hour and is worth it on stain-grade or detailed work.

The same house, two trim specs

Here's how two reasonable specs for one house compare. Illustrative numbers for a roughly 4,000 square foot home; your house and market will differ.

Item	Spec A	Spec B
Material	MDF, paint-grade	White oak, stain-grade
Base	3-1/4" flat	7-1/4" with shoe
Casing	2-1/4" flat	3-1/2" with back band and head cap
Windows	Drywall returns, no stool	Picture-frame casing with jamb extensions
Interior doors	Hollow-core, painted	Solid-core, stained
Crown	None	Main living areas
Rough installed cost	$35,000	$110,000

Both could honestly be called "trim per plans" if the plans don't say. That's the whole point.

How to specify it

You don't need a full millwork drawing. A one-page trim sheet does most of the work: material and paint or stain grade, base height, casing width and profile, how windows are finished, door type, and where crown goes, if anywhere. A photo of a detail you like, with a note on what you like about it, helps a lot.

Send the same sheet to every builder you ask to bid. That's how you get trim numbers you can compare, which matters, because trim is one of the lines most likely to come back with wildly different prices for what looks like the same house. How to get builder bids you can actually compare covers the rest of the package.

Questions worth asking

• What material and grade did you price for trim and doors?
• What base height and casing profile is the price based on?
• How are windows finished: casing, stool and apron, or drywall returns?
• Are jamb extensions included at every window and exterior door?
• Is crown included, and where?
• Are interior doors solid-core or hollow-core, and are they in this line or a separate one?