How old are homes in Highland, and what does that mean for a deck?
18% of homes in Highland's covered ZIP code were built in 2000 or later and 7% before 1960; the largest group dates to the 1980s.
Homes in Highland have a median construction year of 1984, so a deck original to a typical house would now be about 42 years old — beyond the point where wood framing, fasteners and flashing can be assumed sound.
Many decks from the 1970s and 1980s were built before today's detailed deck provisions appeared in model codes. Common issues on decks of this age include corroded hangers, posts set directly in soil and ledger boards fastened with nails. Replacement is often the better value than repeated repairs.
That makes Highland's housing 5 years older than Howard County as a whole, where the median home was built in 1989. Statewide, the median Maryland home was built in 1979. Among the 128 covered Maryland communities with Census data, Highland ranks #77 for oldest housing. In this ZIP code, 7% of homes were built before 1960, 33% between 1960 and 1979, 43% between 1980 and 1999, and 18% since 2000 — the single largest group dates to the 1980s.
| Decade built | Homes | Share |
|---|---|---|
| 2020 or later | 6 | 1% |
| 2010s | 83 | 7% |
| 2000s | 107 | 10% |
| 1990s | 158 | 14% |
| 1980s | 323 | 29% |
| 1970s | 223 | 20% |
| 1960s | 142 | 13% |
| 1950s | 49 | 4% |
| 1940s | 16 | 1% |
| before 1940 | 10 | 1% |
What does Highland's climate mean for deck construction?
Highland averages about 86 days a year at or below freezing, 28.5 inches of snow and 46.4 inches of precipitation, based on NOAA 1991–2020 normals.
The nearest NOAA climate station with 1991–2020 normals is Laurel 3 W, about 7 miles away. It records an average of 86 days a year with a low at or below 32°F — a moderate number of freezing nights. On roughly 75 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 Highland 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.
Average snowfall near Highland is about 28.5 inches a year (Columbia 2.3 N). That's enough that shoveling and ice-melt choices affect deck surfaces, and stair treads benefit from good texture and drainage.
Highland sees about 46.4 inches of precipitation a year, with measurable rain or snow (0.1 inch or more) on about 80 days. Good drainage between boards, clean gaps and a ledger that is properly flashed keep that water from rotting the frame.
Average summer highs reach about 87°F, and around 36 days a year top 90°F. On a deck with full afternoon sun, dark composite can get uncomfortable on those days, so test samples in the sun before choosing a color.
Which decking material makes the most sense in Highland?
For most Highland homes, capped composite is the strongest starting point because about 75 freeze-thaw days a year are hard on unsealed wood.
Budget, upkeep tolerance and sun exposure on your particular lot still decide the final choice between these options.
| Material | How it handles Highland's conditions |
|---|---|
| Pressure-treated pine | Economical; needs sealing to resist freeze-thaw splitting |
| Cedar | Attractive and stable; refinish to keep its color |
| Capped composite | Low maintenance; choose lighter colors for summer heat |
| PVC | Lightest and most moisture-proof; premium price |
What kinds of homes are in Highland, and how does that shape deck design?
Highland has about 1,117 housing units across its covered ZIP code. 99% are single-family detached homes, 1% are attached homes such as townhouses and rowhouses, and about 0% are in buildings with two or more units. Roughly 95% of occupied homes are owner-occupied.
Detached single-family homes dominate in Highland, so most decks are backyard decks attached to the rear of the house. That gives more freedom on size, layout and stairs, and makes a well-planned deck one of the most-used rooms of the home.
What deck projects are most common in Highland?
Based on the age of Highland's housing, the largest group of projects is likely to be replacing or rebuilding aging decks.
- Replacement and major repair: about 704 homes (63%) 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.
- Retrofit decks on older homes: about 217 homes (19%) predate 1970. Here the priority is confirming that add-on decks are properly attached — or rebuilding them freestanding — before any cosmetic work.
- Upgrades and expansions: about 89 homes (8%) 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.
When is the best time to plan a deck project in Highland?
Highland's milder winters — about 86 freezing nights a year — allow construction through most of the year. Peak summer heat (around 36 days at 90°F+) is the hardest time to apply stain or work in full sun, so many projects are scheduled for spring and fall.
Do you need a permit to build a deck in Highland?
Often, yes — especially for attached or elevated decks — but the rules are set locally. Check with the building department that serves your address: the municipality, or Howard County for unincorporated areas.
For Highland, MD, 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 Maryland is on our state page; local rules change, so the building department remains the authority.
How does Highland compare with nearby covered areas?
The closest covered area is Ashton, about 2.4 miles from the center of Highland's covered ZIPs. Its median home was built in 1994, 10 years later than in Highland. Highland has 5 percentage points more detached single-family homes (99% vs. 94%), which changes how many projects are backyard decks versus compact townhouse decks. Owner-occupancy is 95% in Highland compared with 98% in Ashton. Highland's covered ZIP code span about 7.5 square miles of land with roughly 1,117 homes — about 149 per square mile, a low density that usually allows larger decks and freestanding designs.
| Area | Distance | Median year built | Covered ZIPs |
|---|---|---|---|
| Ashton | 2.4 mi | 1994 | 1 |
| Fulton | 2.5 mi | 2011 | 1 |
| Brinklow | 2.6 mi | 1975 | 1 |
| Clarksville | 2.7 mi | 1998 | 1 |
| Spencerville | 3.4 mi | 1958 | 1 |
| Sandy Spring | 3.9 mi | 1988 | 1 |
Deck planning checklist for Highland homeowners
- Confirm your ZIP code is 20777, the covered Highland ZIP.
- Find out when your current deck was built and whether it uses pre-2004 treated lumber.
- Test board samples in afternoon sun before choosing a color.
- Probe the ledger, post bases and joist tops for soft wood before planning a resurface.
- Call 811 before any digging so utility lines are marked.

