Interior Painting across Abington, Massachusetts.

Census estimates put the median year built for local housing at 1970, but that middle number hides a wide spread. About 21.1% of the town's 6,479 housing units date from 1939 or earlier, roughly 994 units from the 1950s, about 908 from the 1970s, and 20.0% from 2000 or later. A bedroom in a pre-war house and a bedroom in a 2005 build need different preparation, even if the color on the card is the same.

So the first questions for an interior job aren't about color. They're about what the walls are made of, how many coats are already on the trim, and whether any of that old paint will be sanded or scraped.

Plaster, drywall and what each needs

Older houses may still have original plaster on wood or metal lath. Plaster can show hairline cracks, loose patches where the keys have let go, and bulges near ceilings. Those areas get secured or cut back and patched before priming, because paint alone won't hold a failing patch in place.

Mid-century and newer homes are more likely to have drywall. The common issues there are nail pops, taped seams that show through flat paint, and dents along hallways. A skim of joint compound and a primer suited to fresh patches keeps the repairs from flashing through the finish coat.

Ceilings deserve their own plan. Water stains need a stain-blocking primer first, or they can bleed back through a fresh coat of white within days.

Lead dust and pre-1978 rooms

Census tables show 63.4% of housing units in town were built before 1980. The census groups the 1970s as a single decade, so it can't say exactly how many units predate 1978, the cutoff in federal lead rules. What it does show is that 3,198 units (49.4%) were built before 1970, all of them inside that window.

Under the EPA's Renovation, Repair and Painting rule, paid work that disturbs paint in a home built before 1978 must be done by a certified firm using lead-safe practices. Inside a house, that matters most on window sashes, stools and jambs, door edges, stair treads and baseboards, where friction and sanding create dust. Our lead-safe painting page covers containment, cleanup and verification.

• Rooms sealed off with plastic and doorways covered
• Wet scraping and sanding instead of dry methods
• HEPA vacuuming and wet wiping at the end of each day
• Furniture moved and covered, floors protected

Trim from different decades

Woodwork tells you a lot about a room's history. Trim in an older house may carry many coats, some of them oil-based, and new latex won't bond well to slick oil enamel without a deglossing step and a bonding primer. Flat stock casing in a 1970s house is simpler but may have been painted with low-sheen wall paint that scuffs easily.

For doors, trim and cabinets that get handled, a harder satin or semi-gloss enamel holds up better than wall paint. Our paint finish comparison explains where each sheen belongs.

Planning the job

Interior work can go on all year, so fall and winter are reasonable times to book rooms that would otherwise wait. The winter interior painting guide covers ventilation and drying when the windows stay shut, and this prep checklist shows what to clear before the crew arrives. Neighborhood notes are on our North Abington, South Abington and East Abington pages, and kitchen cabinets have their own cabinet painting page.