How old are homes in Howard County, and what does that mean for decks?
The median home in Howard County was built in 1989; 5% predate 1960 and 29% were built since 2000.
Howard County has about 125,286 homes, with a median construction year of 1989 (the Maryland median is 1979). Within our covered ZIP codes — about 123,343 homes — the median is 1989, close to the county as a whole.
Homes in the covered parts of Howard County have a median construction year of 1989, so a deck original to a typical house would now be about 37 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.
| Decade built | Homes | Share |
|---|---|---|
| 2020 or later | 1,862 | 1% |
| 2010s | 17,347 | 14% |
| 2000s | 17,584 | 14% |
| 1990s | 23,487 | 19% |
| 1980s | 28,675 | 23% |
| 1970s | 21,050 | 17% |
| 1960s | 8,404 | 7% |
| 1950s | 3,718 | 3% |
| 1940s | 820 | 1% |
| before 1940 | 2,339 | 2% |
Which Howard County communities have the oldest and newest homes?
Among covered Howard County communities, Savage has the oldest housing (median 1960) and Annapolis Junction the newest (median 2015).
Oldest housing: Savage (1960), Columbia (1982) and Dayton (1984). In these communities, expect retrofit decks on older houses and aging decks that need structural inspection, ledger and flashing upgrades, or replacement. Newest housing: Annapolis Junction (2015), Fulton (2011) and Glenelg (2002). Here, projects lean toward enlarging builder-installed decks, adding stairs and railings, and upgrading to low-maintenance boards.
How does Howard County's climate affect deck building?
Covered parts of Howard County average about 86 days a year at or below freezing (NOAA 1991–2020 normals, 4 stations). Across the covered communities, nearby stations range from about 86 to 98 freezing days a year, so conditions differ noticeably between Howard County's higher, more rural areas and its urban core.
The nearest NOAA climate station with 1991–2020 normals is Laurel 3 W, about 4 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 Howard County 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 Howard County 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.
Howard County sees about 49.7 inches of precipitation a year, with measurable rain or snow (0.1 inch or more) on about 85 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.
What deck projects are most common in Howard County?
Based on the age of Howard County's housing, the largest group of projects is likely to be replacing or rebuilding aging decks.
- Replacement and major repair: about 73,212 homes (58%) 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 19,209 homes (15%) 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.
- Retrofit decks on older homes: about 15,281 homes (12%) predate 1970. Here the priority is confirming that add-on decks are properly attached — or rebuilding them freestanding — before any cosmetic work.
Which Howard County communities do you serve?
17 communities in Howard County have covered ZIP codes. Only the ZIPs listed are covered.
| Community | Covered ZIPs here | Median year built | Detached homes |
|---|---|---|---|
| Columbia | 21044, 21045, 21046 | 1982 | 39% |
| Ellicott City | 21042, 21043 | 1991 | 58% |
| Annapolis Junction | 20701 | 2015 | 0% |
| Clarksville | 21029 | 1998 | 90% |
| Cooksville | 21723 | 2002 | 100% |
| Dayton | 21036 | 1984 | 99% |
| Elkridge | 21075 | 2000 | 33% |
| Fulton | 20759 | 2011 | 57% |
| Glenelg | 21737 | 2002 | 100% |
| Glenwood | 21738 | 1992 | 96% |
| Highland | 20777 | 1984 | 99% |
| Jessup | 20794 | 1991 | 44% |
| Laurel | 20723 | 1992 | 39% |
| Marriottsville | 21104 | 1995 | 89% |
| Savage | 20763 | 1960 | 37% |
| West Friendship | 21794 | 1994 | 100% |
| Woodbine | 21797 | 1985 | 91% |
What decking material works best in Howard County?
Capped composite is a strong default for Howard County because about 75 freeze-thaw days a year are hard on unsealed wood and many elevated townhouse decks are hard to reach for re-staining.
50% of Howard County's homes are detached single-family houses and 22% are townhouses or other attached homes; 71% of occupied homes are owner-occupied. The sizable townhouse share means many elevated rear decks where re-staining is awkward, which tilts the value toward composite or PVC.
Who issues deck permits in Howard County?
It depends on where you live: incorporated cities and towns in Howard County usually run their own permit offices, while unincorporated areas are typically served by Howard County.
Maryland adopts a statewide building performance standard, and counties and municipalities enforce it, often with local amendments. Your county permitting office issues deck permits. Before work starts, confirm with the building department for your exact address whether a permit is required, what drawings and inspections it involves, and whether an HOA must approve the design.

