Exterior Painting right here in Northborough, Massachusetts.

How well a new exterior coat holds up here depends on three questions: whether the property sits in a local historic district, how much shade and moisture the walls get, and what is in the old paint layers.

The town's 2020 master plan notes that most parcels here were developed between 1960 and 1999. A house built in that span is now about 27 to 66 years old, which means the current paint sits over earlier coats whose condition decides how much scraping and priming the next job needs.

Historic districts and the NHDC

Northborough has two local historic districts: the Meeting House Common Historic District, set up at the April 1973 Town Meeting, and the single-building district at the Peter Whitney Parsonage. According to the Northborough Historical Society, the Meeting House Common district includes seven private homes along with the Unitarian Church, the colonial section of the Howard Street Cemetery and the Minuteman Muster Site.

The Northborough Historic District Commission handles exterior design review for improvements inside those districts. If your home is one of them, call the commission before ordering paint or replacing trim, shutters or doors, and ask which parts of the job need a certificate. Outside those two districts the commission's design review doesn't apply, but the town's 2008 historic resources survey named potential National Register districts, including 10, 12 and 16 Chapin Court (Davis Mill workers' housing) and a section of Main Street along the Boston Post Road; on houses there, period-appropriate colors are worth considering even without a review requirement.

Pine shade and mildew

The master plan describes the town's forests as mostly white pine and hemlock. Evergreens keep shading a wall all year, so north and east elevations under tall pines can stay damp long after a storm. That is where you see green mildew on clapboards, soft wood at the bottoms of corner boards, and paint lifting at the drip edge of window sills.

On those walls, washing with a mildewcide, letting the siding dry fully, replacing rotted trim and using a paint with mildew resistance matter more than the brand on the can. Trimming branches back from the roofline and siding helps the next coat last. Pine needles packed into gutters also overflow onto fascia and trim, so cleaning them is part of keeping paint intact.

Lead in the old layers

Census data shows 49.3% of local housing units were built before 1980, and lead was banned from residential paint in 1978. Exterior trim, sills and porch parts on a house from before then may carry lead under newer coats.

Scraping and sanding that paint is regulated in Massachusetts: plastic sheeting on the ground, no power sanding without HEPA dust collection, collection of paint chips and a careful cleanup at the end of each day. That matters near vegetable gardens and play areas. Our lead-safe painting page explains the steps.

Prep by siding type

Weather sets the calendar. Paint labels list a minimum air and surface temperature, and late-season dew can ruin a coat that went on in the afternoon. The post on painting into November covers the cut-off, and common exterior paint failures shows what each kind of peeling means. For the deck and porch, see deck staining in Northborough.

• Wood clapboard: scrape loose paint, feather edges, spot-prime bare wood, caulk vertical joints and trim gaps, then two finish coats
• Cedar shingles: solid stain or paint over sound coats; shingles that are cupped or split get replaced first
• Vinyl with painted trim: trim, doors and shutters are the painted parts; vinyl itself can be painted with vinyl-safe colors that don't overheat the panels
• Pre-1940 houses: decades of oil coats over old wood can need more scraping and a slow-drying oil primer before a modern topcoat