Interior Painting across Concord, Massachusetts.

The age spread of the local housing stock is wide. In Census estimates, 22.6% of units date to 1939 or earlier, the 1950s through 1970s account for 39.2%, and 19.6% went up in 2000 or later. Those three groups tend to need very different prep before a roller touches the wall, so an interior estimate starts with what the walls are made of and how many layers they already carry.

Exterior design review in the town's historic districts concerns work visible from a public way. Painting inside a house is not among the items the district guidelines list for review, so interior colors are left to the owner, even in a district house.

Old plaster needs a different approach

If your walls are original plaster, the common problems are hairline cracks that return every winter, bulges where the plaster has let go of the lath, and patches from past repairs that read through the paint. Rolling fresh paint over them only hides the issue for a season. Loose sections get reattached or cut out and filled, cracks get taped or bridged with a flexible compound, and the patched areas are primed so they do not flash through the finish coat.

Ceilings in older rooms deserve the same look. A sagging plaster ceiling should be stabilized before painting, and many decades of calcimine or distemper paint on an old ceiling can refuse to hold a modern coat until it is washed off or sealed.

Lead dust is an indoor issue first

With 64.7% of local units built before 1980, many interiors may still have lead-based paint on window sashes, stools, door jambs and baseboards, the surfaces that rub and chip. EPA's Renovation, Repair and Painting rule covers paid work in pre-1978 housing that disturbs more than six square feet of paint per room, and window replacement is covered no matter how small. Sanding a single set of window stools and a door can cross that line.

Lead-safe interior work means sealing the room with plastic, keeping dust down with wet methods and HEPA vacuums, and cleaning and verifying before furniture goes back. The lead-safe painting page explains the process, and families with small children may want to read painting with kids and pets at home too.

Trim from different eras

The town's design guidelines trace local architecture from Colonial work of the early 1700s through Colonial Revival houses built as late as 1940. Inside houses from those periods, paneled doors, raised wainscot, built-in cupboards and deep window casings are the slow part of the job, because each profile is cut in by brush and every old drip or failed coat on it needs sanding first.

In houses from the 1950s through 1970s, the trim may carry oil-based enamel. Latex will peel off a glossy oil coat unless the surface is deglossed and primed with a bonding primer, so a quick test with denatured alcohol on a hidden spot is worth doing before the job is quoted. The latex vs. oil comparison covers the chemistry.

Choosing finishes room by room

Flat or matte hides the imperfections of old plaster best, while eggshell or satin wipes clean in hallways and kitchens, and semi-gloss holds up on trim and doors. The interior paint finish comparison goes through each sheen. Interior work is not tied to the weather, so it can be scheduled through the winter; see winter interior painting in Massachusetts.