Deck builders in Boston, MA

The median home in Boston dates to about 1955, roughly 71 years ago. Most homes from that era were built without a deck; the decks you see now were usually added in later decades, sometimes by previous owners with little documentation.

That history matters: retrofit decks are where missing ledger flashing, undersized footings and nailed-rather-than-bolted connections are most common. Before resurfacing or extending an add-on deck, it is worth confirming how it was framed and attached.

That makes Boston's housing 6 years newer than Suffolk County as a whole, where the median home was built in 1949. Statewide, the median Massachusetts home was built in 1964. Among the 113 covered Massachusetts communities with Census data, Boston ranks #43 for oldest housing. In these ZIP codes, 52% of homes were built before 1960, 15% between 1960 and 1979, 9% between 1980 and 1999, and 24% since 2000 — the single largest group dates to the before 1940.

The nearest NOAA climate station with 1991–2020 normals is Boston Logan Intl. AP, about 2 miles away. It records an average of 92 days a year with a low at or below 32°F — a moderate number of freezing nights. On roughly 69 of those days the temperature climbs back above freezing, so water in wood, soil and gaps between boards repeatedly freezes and thaws.

Frost is less severe in Boston than in northern states, but footings still have to meet the local frost-depth requirement, and freeze-thaw cycles are enough to work loose nails and open checks in unsealed wood.

Snow is a major factor: the Boston Logan Intl. AP station averages about 49.2 inches a year. Framing has to carry snow load, stairs need a plan for winter use, and snow removal should be done with plastic-bladed shovels and ice-melt products the decking manufacturer allows.

Boston sees about 43.6 inches of precipitation a year, with measurable rain or snow (0.1 inch or more) on about 77 days. Good drainage between boards, clean gaps and a ledger that is properly flashed keep that water from rotting the frame.

Summer heat is mild by comparison — average summer highs near 80°F and only about 14 days a year at 90°F or above — so board color can be chosen mostly on looks.

On Boston's many older homes, a wood-look capped composite or a stained cedar deck usually suits the architecture better than high-gloss boards.

Boston has about 84,324 housing units across its covered ZIP codes. 1% are single-family detached homes, 3% are attached homes such as townhouses and rowhouses, and about 96% are in buildings with two or more units. Roughly 25% of occupied homes are owner-occupied.

Because so much of the housing in Boston is multi-unit, a meaningful number of decks and balconies are governed by condominium or building associations. For single-family homes and townhouses here, check whether any association rules apply before you design.

Because fewer than half of homes here are owner-occupied, rental property owners make up a share of deck decisions here; durable, low-maintenance materials often make sense for them.

• Retrofit decks on older homes: about 50,116 homes (59%) predate 1970. Here the priority is confirming that add-on decks are properly attached — or rebuilding them freestanding — before any cosmetic work.
• Replacement and major repair: about 14,334 homes (17%) were built between 1970 and 1999, the age group whose original or early add-on decks are most likely to have worn-out framing, connectors and boards.
• Upgrades and expansions: about 13,400 homes (16%) were built since 2010. Their decks are usually sound but small or builder-grade, so enlarging the deck, adding stairs and switching to composite or upgraded railings are common.

Boston has a defined building season. Spring and early fall offer the most comfortable working weather; winter is a good time to settle the design and apply for permits. Stains and sealers generally need dry weather and moderate temperatures, so plan wood finishing for late spring or early fall.

For Boston, MA, ask the permit office whether your deck needs a permit based on its size, height and attachment to the house, which drawings and inspections are required. Statewide code background for Massachusetts is on our state page; local rules change, so the building department remains the authority.

The closest covered area is Roxbury Crossing, about 1.7 miles from the center of Boston's covered ZIPs. Its median home was built in 1976, 21 years later than in Boston. The two have a similar share of detached single-family homes (1% vs. 2%). Owner-occupancy is 25% in Boston compared with 9% in Roxbury Crossing. Boston's covered ZIP codes span about 5.9 square miles of land with roughly 84,324 homes — about 14,292 per square mile, dense enough that lot size, access for materials and neighbors' sightlines shape most deck plans.