Interior Painting across Cape Cod, Massachusetts.

Start with the age of the house. Census figures put the median year built for Barnstable County at 1977, and the two busiest building decades were the 1970s (32,298 units still standing) and the 1980s (33,181). Together those two decades account for roughly two of every five homes in the county.

For interior work, that age profile matters more than any coastal setting. A room finished in that era has its own repaint questions: ceilings that may carry a sprayed texture, builder-grade trim with decades of glossy coats on it, and wall finishes that have been touched up so many times the sheen no longer matches from one patch to the next.

Plaster and older trim where the stock is oldest

Countywide, 11.4% of housing units were built in 1939 or earlier, but that share swings hard from one town to the next. In Provincetown it is 41.0%; in Bourne 18.0%; in Mashpee only 2.5%, where the median home dates to 1988. The Cape Cod Commission notes that structures from 1750 or earlier sit along the Old King's Highway in Sandwich, Barnstable and Yarmouth, and that Provincetown has a large number of buildings from 1851 to 1900.

In a house of that vintage, walls may be plaster rather than drywall. Plaster takes paint well once it is sound, but hairline cracks, loose keys and old calcimine or distemper coatings have to be found first. A test patch tells you whether the existing finish will hold a new coat or needs a bonding primer. Window stools, door casings and stair parts in these houses can carry many layers, and the oldest of those layers deserve care before anyone sands them.

Lead paint in the interior

According to the same Census table, 56.4% of the county's homes were built before 1980. The EPA's Renovation, Repair and Painting rule covers paid work that disturbs paint in housing built before 1978, and it requires the firm to be certified in lead-safe work practices. Inside a home, the surfaces that matter most are the ones that get sanded, scraped or rubbed: window sashes and sills, door edges, stair treads and baseboards.

Lead-safe interior work means plastic sheeting over floors and furniture, closing off the work area from the rest of the house, sanding methods that keep dust down, and a specialized cleanup and verification before the room is used again. Our lead-safe painting page walks through each step, and it applies whether the house went up in Dennis in 1972 or in Provincetown in the 1880s.

When the house is closed part of the year

The Census classifies 33.1% of the county's housing units as vacant for seasonal, recreational or occasional use. In Truro that share is 67.8%, and in Chatham, Wellfleet, Eastham and Dennis it is above half. If yours is one of those houses, an interior repaint can be planned for the stretch when nobody is using it, with a few conditions settled in advance.

Paint labels list a minimum air and surface temperature for application and drying, so a house that is shut down for winter needs its heat running before, during and for a period after the work. Decide who will let the crew in, where the key or lockbox code lives, and how you want to see the finished rooms if you are not there for the final walkthrough. Our article on painting interiors in winter covers keeping the heat even and ventilating with the windows shut.

Scoping the job

A written estimate from a free on-site visit lists the rooms, surfaces and prep included, so you can compare it line by line with other quotes. If the exterior or kitchen cabinets are also on your list, see the exterior painting and cabinet painting pages for the Cape.

• Ceilings: flat, textured or previously painted with a glossier product, each of which changes primer and roller choice
• Walls: drywall with nail pops and old patches, or plaster with cracks to be cut out and filled
• Trim and doors: oil-based coats from earlier decades need a bonding primer before waterborne enamel
• Finish: sheen by room, using the interior paint finish comparison as a starting point