Millwork is the finished face of a house. Doors, moulding, stair parts, and hardware turn a framed shell into rooms that feel complete, and most homeowners interact with millwork dozens of times a day without naming it. The suppliers who make and sell these pieces range from small shops that cut a single custom profile to full-service lumberyards that stock entire product lines, and the industry has consolidated steadily as family firms join larger operations. Consolidation is not unique to millwork: lender groups and builder associations have joined forces to develop green mortgage financing products for builders, and similar combinations reshape supply chains. For contractors and homeowners alike, understanding how millwork is made, sold, and installed is the difference between a trim package that fits the budget and a change order at the end of the job.
What Millwork Includes and Why It Matters
Millwork covers any wood product manufactured in a mill and finished for installation in a building. The four main families are doors, moulding, stairs, and the hardware that ties them together. Doors include entry units, interior passage doors, bifolds, and closet systems. Moulding includes baseboards, crown, window and door casings, chair rails, and panel moulds. Stair work covers treads, risers, stringers, balusters, and handrails. Hardware includes hinges, locksets, pulls, and the fasteners and adhesives used to mount everything.
Trim and millwork typically take 5 to 10 percent of a new home’s finishing budget, depending on the detail specified. The pieces also carry structural responsibilities that are easy to overlook. Door frames transfer load around the opening, stair stringers carry live loads from people and furniture, and handrails have to resist push and pull forces from every direction. The same engineering logic used to calculate dam forces on water infrastructure applies, at a smaller scale, to a railing that has to hold a falling body weight.
Interior vs Exterior Millwork
Exterior millwork fights weather. Entry doors, exterior trim, and porch columns see rain, sun, and freeze-thaw cycles, so they use species and finishes chosen for stability, like clear vertical-grain cedar, composite materials, or factory-finished fiberglass. Interior millwork lives in a controlled climate, which allows wider species selection and more delicate profiles, from painted MDF baseboard to rift-sawn oak crown.
Architectural Millwork Grades
Not all millwork is graded the same. Architectural millwork, built to the specifications of the Architectural Woodwork Institute, requires tight tolerances, matched grain, and specified joinery, and it carries a premium. Commodity millwork is manufactured to commercial standards with fewer restrictions on knots and color variation. Specifying the grade up front prevents surprises at the estimating stage.
How Millwork Suppliers and Fabricators Operate
The path from tree to installed trim runs through several hands. Lumber mills cut and kiln-dry the raw material; distributors warehouse it in volume; millwork shops and lumberyards fabricate profiles, assemble door units, and finish stair parts; and contractors or trim carpenters install the pieces. Full-service suppliers combine several of these roles under one roof, so a homeowner can buy moulding and get advice on coping corners in the same visit.
Supplier networks also reach into community work. When volunteers joined forces with AIA Detroit on a six-day remodel project, the effort depended on donated materials and coordinated trades, the same supply chain that serves paying jobs. Whether the project is volunteer or commercial, the workflow from order to installation follows the same sequence.
The Order-to-Installation Workflow
- Take field measurements of openings, wall lengths, and stair runs before ordering anything.
- Select profiles and materials, then confirm lead times with the supplier.
- Place the order with shop drawings for anything custom, like curved casing or a built-up stair.
- Receive and stage materials in a dry space for several days so they acclimate to the house.
- Install in the standard sequence: doors and frames first, then casing, base, and crown, then stair parts and hardware.
Lead Times and Scheduling
Custom millwork is not a shelf item. A standard interior door is stocked at most lumberyards, but a custom entry door or a run of matching crown moulding is fabricated to order, with lead times from two to eight weeks depending on the shop’s load. Ordering millwork early, at the rough-in stage, keeps the schedule from stalling while materials catch up.
Custom Doors: Materials, Construction and Hardware
Doors are the most-used millwork item in a house, and the material choice drives cost and performance. Solid wood doors offer the classic look and can be trimmed or refinished over decades, but they move with humidity and cost the most. Flush and panel doors built on a plywood or engineered core stay flat and stable at a lower price. MDF doors paint smoothly with no grain show-through, and fiberglass entry doors resist weather and insulate better than wood, though they cannot be carved or reshaped.
Doors also connect to the rest of the interior. Millwork that shares a finish language, from door panels to built-in storage solutions, makes a house feel designed rather than assembled, and suppliers that fabricate both can match profiles across the whole project.
| Material | Cost | Stability | Finish options | Best use |
|---|---|---|---|---|
| Solid wood | Highest | Moves with humidity | Stain or paint | Entry and formal rooms |
| Engineered core | Moderate | Very stable | Paint or veneer | Interior passage doors |
| MDF | Low to moderate | Stable, heavy | Paint only | Painted interior doors |
| Fiberglass | Moderate to high | Very stable | Factory finish | Exterior entries |
Door Hardware and Seals
Hardware turns a door into an entry system. Hinges must carry the door weight, typically three hinges for a standard 80-inch door and four for tall or heavy units. Locksets and handles should match the door’s backset and bore, and commercial-grade hardware is worth the premium on high-use doors.
Weatherstripping Choices
Exterior doors need a continuous seal. Magnetic weatherstripping pairs with steel and fiberglass doors for a tight latch, compression bulb strips work on wood doors, and door sweeps close the gap at the bottom. A door that seals properly saves more energy than most single upgrades and keeps cold air off the surrounding trim finish.
Moulding Profiles and Trim Installation
Moulding is where millwork earns its reputation, because profiles define the style of a room. The same wall looks different with a 3-inch painted baseboard than with an 8-inch built-up crown. Common profiles include baseboard, casing around doors and windows, crown at the ceiling, chair rail at wainscot height, and picture rail for hanging art.
- Baseboard: 3 to 8 inches tall, flat or stepped, protects the wall at floor level
- Casing: 2 to 4 inches wide, frames doors and windows, often mitered at the top corners
- Crown: 3 to 8 inches, angled at the ceiling line, the most visible profile in a room
- Chair rail: 30 to 36 inches high, divides wall finishes and protects from furniture
- Panel mould: thin strips used to build wall paneling and cabinet details
Installation quality shows in the corners. Professional carpentry and trim work copes inside corners so the joint stays tight as wood expands and contracts, rather than relying on mitered joints that open up with seasonal movement.
Coping Inside Corners
Coping means cutting the end of one piece to the profile of the piece it meets, so the joint hides movement. Mark the profile, cut back to the line with a coping saw, and test the fit against the adjoining piece. Coped corners take practice, but they are the standard mark of finished trim.
Mitering Outside Corners
Outside corners need mitered joints cut at 45 degrees, and the pieces must be cut slightly long and coaxed into place so the joint closes tight. A power miter saw with a sharp blade and a stop block for repeat cuts keeps outside corners consistent across the room.
Stairs and Railings: Codes and Construction
Stair millwork is structural first and decorative second. A staircase is built on stringers, the sloped members that carry the treads and risers, and every connection has to transfer load into the framing around it. That is why stair design follows the same discipline as the load paths in residential wood framing that keep the rest of the house standing: gravity loads come down through the treads into the stringers, and lateral loads push against the railing system.
Building codes set the geometry. The International Residential Code caps riser height at 7.75 inches, requires a minimum tread depth of 9 inches, nosing to nosing, and holds handrails between 34 and 38 inches above the stair nosing. Headroom must clear 6 feet 8 inches. Deviating from these dimensions makes a staircase uncomfortable at best and a code violation at worst.
| Element | IRC requirement |
|---|---|
| Maximum riser height | 7.75 in |
| Minimum tread depth | 9 in (nosing to nosing) |
| Handrail height | 34-38 in above nosing |
| Minimum headroom | 6 ft 8 in |
| Minimum stair width | 36 in |
Stair Construction Basics
Open-stringer stairs show the tread ends and need a skirt board, while closed-stringer stairs hide them. Treads are typically 1-inch solid hardwood or engineered material, risers are 3/4 inch, and the nosing overhangs the riser by about 3/4 to 1 1/4 inches. Prefabricated stair parts, including pre-cut stringers and pre-finished treads, shorten installation time, while custom work allows curved or tapered treads for unusual layouts.
Railing and Baluster Spacing
Handrails must resist 200 pounds of concentrated load in any direction, and balusters must be spaced so a 4-inch sphere cannot pass between them, the standard that keeps small children from slipping through. Posts anchor the rail to the structure with bolts or structural connectors, never nails alone.
Planning a Millwork Package
A millwork package is the complete list of doors, moulding, stair parts, and hardware for a project, and planning it as one order saves money and coordination trouble. Start with a style decision, because every profile family, from Craftsman to contemporary, changes the product list. Then count openings, measure wall lengths, and add 10 percent waste for cuts and mistakes.
Style Selection
Style drives the profile list. Colonial rooms use tall baseboard, paneled doors, and dentil crown; Craftsman interiors use flat casings, square profiles, and exposed joinery; modern rooms use minimal trim or none at all. A room’s millwork should echo its architecture, and suppliers’ showrooms make it easy to compare profiles side by side. Historic styles remain a specialty: reproducing neoclassical millwork and trim for a federal-style mantel requires matching specific proportions and moldings that stock catalogs rarely cover.
Budgeting for Millwork
Get itemized quotes from at least two suppliers and compare installed versus material-only pricing. Door units often cost more than homeowners expect because hardware, jambs, and casing add up quickly. Set a contingency of 10 to 15 percent of the millwork budget for custom pieces and last-minute changes, and order early enough that lead times do not stall the finish schedule.