How old are homes in Will County, and what does that mean for decks?
The median home in Will County was built in 1992; 15% predate 1960 and 33% were built since 2000.
Will County has about 254,278 homes, with a median construction year of 1992 (the Illinois median is 1971). Within our covered ZIP codes — about 78,524 homes — the median is 1995, 3 years newer than the county overall.
The median home in the covered parts of Will County was built around 1995. A deck built with a house of that age is now about 31 years old — the stage where first-generation pressure-treated decks commonly need major repair or replacement.
Decks built before 2004 were very likely made with CCA-treated lumber, which was phased out of most residential uses at the end of 2003. That doesn't make an existing deck unsafe, but old boards shouldn't be burned, and demolition debris should be disposed of according to local rules.
| Decade built | Homes | Share |
|---|---|---|
| 2020 or later | 3,105 | 1% |
| 2010s | 15,902 | 6% |
| 2000s | 64,764 | 25% |
| 1990s | 53,623 | 21% |
| 1980s | 22,729 | 9% |
| 1970s | 34,464 | 14% |
| 1960s | 20,449 | 8% |
| 1950s | 15,671 | 6% |
| 1940s | 6,036 | 2% |
| before 1940 | 17,535 | 7% |
Which Will County communities have the oldest and newest homes?
Among covered Will County communities, Bolingbrook has the oldest housing (median 1989) and Romeoville the newest (median 1999).
Oldest housing: Bolingbrook (1989), Naperville (1989) and Lockport (1992). In these communities, expect retrofit decks on older houses and aging decks that need structural inspection, ledger and flashing upgrades, or replacement. Newest housing: Romeoville (1999), Plainfield (1997) and Lockport (1992). Here, projects lean toward enlarging builder-installed decks, adding stairs and railings, and upgrading to low-maintenance boards.
How does Will County's climate affect deck building?
Covered parts of Will County average about 123 days a year at or below freezing (NOAA 1991–2020 normals, 2 stations). Across the covered communities, nearby stations range from about 123 to 144 freezing days a year, so conditions differ noticeably between Will County's higher, more rural areas and its urban core.
The nearest NOAA climate station with 1991–2020 normals is Romeoville WFO, about 2 miles away. It records an average of 123 days a year with a low at or below 32°F — a substantial freezing season. On roughly 81 of those days the temperature climbs back above freezing, so water in wood, soil and gaps between boards repeatedly freezes and thaws.
For Will County, that means footings must bear below the locally required frost depth to avoid heaving, and wood surfaces should be kept sealed so absorbed water doesn't split boards over winter. Synthetic decking tolerates freeze-thaw well but still needs the manufacturer's expansion gaps.
Average snowfall near Will County is about 33.2 inches a year (Romeoville WFO). That's enough that shoveling and ice-melt choices affect deck surfaces, and stair treads benefit from good texture and drainage.
Will County sees about 41.1 inches of precipitation a year, with measurable rain or snow (0.1 inch or more) on about 76 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 83°F, and around 16 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 Will County?
Based on the age of Will County's housing, the largest group of projects is likely to be replacing or rebuilding aging decks.
- Replacement and major repair: about 110,816 homes (44%) 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 59,691 homes (23%) 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 19,007 homes (7%) 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.
Which Will County communities do you serve?
5 communities in Will County have covered ZIP codes. Only the ZIPs listed are covered.
| Community | Covered ZIPs here | Median year built | Detached homes |
|---|---|---|---|
| Bolingbrook | 60440, 60490 | 1989 | 72% |
| Lockport | 60441 | 1992 | 72% |
| Naperville | 60564 | 1989 | 64% |
| Plainfield | 60544 | 1997 | 71% |
| Romeoville | 60446 | 1999 | 69% |
What decking material works best in Will County?
Capped composite is a strong default for Will County because about 81 freeze-thaw days a year are hard on unsealed wood and roughly 33.2 inches of snow a year means regular shoveling.
74% of Will County's homes are detached single-family houses and 11% are townhouses or other attached homes; 83% of occupied homes are owner-occupied. With mostly detached homes, wood remains a practical lower-cost option for homeowners willing to clean and seal on schedule.
Who issues deck permits in Will County?
It depends on where you live: incorporated cities and towns in Will County usually run their own permit offices, while unincorporated areas are typically served by Will County.
Illinois building codes for single-family homes are largely adopted and enforced at the municipal and county level, so requirements differ between suburbs. Contact your village or city building department. 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.