How old are homes in Lockport, and what does that mean for a deck?
36% of homes in Lockport's covered ZIP code were built in 2000 or later and 26% before 1960; the largest group dates to the 2000s.
The median home in Lockport was built around 1992. A deck built with a house of that age is now about 34 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.
That is about the same as Will County overall (median 1992). Statewide, the median Illinois home was built in 1971. Among the 102 covered Illinois communities with Census data, Lockport ranks #96 for oldest housing. In this ZIP code, 26% of homes were built before 1960, 17% between 1960 and 1979, 21% between 1980 and 1999, and 36% since 2000 — the single largest group dates to the 2000s.
| Decade built | Homes | Share |
|---|---|---|
| 2020 or later | 206 | 2% |
| 2010s | 790 | 6% |
| 2000s | 3,920 | 29% |
| 1990s | 2,249 | 17% |
| 1980s | 526 | 4% |
| 1970s | 987 | 7% |
| 1960s | 1,284 | 10% |
| 1950s | 1,572 | 12% |
| 1940s | 411 | 3% |
| before 1940 | 1,530 | 11% |
What does Lockport's climate mean for deck construction?
Lockport averages about 123 days a year at or below freezing, 33.2 inches of snow and 41.1 inches of precipitation, based on NOAA 1991–2020 normals.
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 Lockport, 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 Lockport 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.
Lockport 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.
Which decking material makes the most sense in Lockport?
For most Lockport homes, capped composite is the strongest starting point 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.
Budget, upkeep tolerance and sun exposure on your particular lot still decide the final choice between these options.
| Material | How it handles Lockport'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; handles moisture and freeze-thaw well |
| PVC | Lightest and most moisture-proof; premium price |
What kinds of homes are in Lockport, and how does that shape deck design?
Lockport has about 13,475 housing units across its covered ZIP code. 72% are single-family detached homes, 15% are attached homes such as townhouses and rowhouses, and about 12% are in buildings with two or more units. Roughly 84% of occupied homes are owner-occupied.
The mix of detached homes and attached or multi-unit housing in Lockport means deck projects range from large backyard decks to compact rear decks on narrow lots. Lot size, neighbors' sightlines and any association rules shape the right design.
What deck projects are most common in Lockport?
Based on the age of Lockport's housing, the largest group of projects is likely to be retrofitting or rebuilding decks added to older homes.
- Retrofit decks on older homes: about 4,797 homes (36%) 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 3,762 homes (28%) 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 996 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.
When is the best time to plan a deck project in Lockport?
Lockport 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.
Do you need a permit to build a deck in Lockport?
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 Will County for unincorporated areas.
For Lockport, IL, 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 Illinois is on our state page; local rules change, so the building department remains the authority.
How does Lockport compare with nearby covered areas?
The closest covered area is Romeoville, about 3.7 miles from the center of Lockport's covered ZIPs. Its median home was built in 1999, 7 years later than in Lockport. The two have a similar share of detached single-family homes (72% vs. 69%). Owner-occupancy is 84% in Lockport compared with 81% in Romeoville. Lockport's covered ZIP code span about 28.1 square miles of land with roughly 13,475 homes — about 480 per square mile, a low density that usually allows larger decks and freestanding designs.
| Area | Distance | Median year built | Covered ZIPs |
|---|---|---|---|
| Romeoville | 3.7 mi | 1999 | 1 |
| Lemont | 6.9 mi | 1992 | 1 |
| Bolingbrook | 7.3 mi | 1989 | 2 |
| Plainfield | 8.8 mi | 1997 | 1 |
| Woodridge | 10.1 mi | 1981 | 1 |
| Darien | 11.1 mi | 1978 | 1 |
Deck planning checklist for Lockport homeowners
- Confirm your ZIP code is 60441, the covered Lockport ZIP.
- Find out when your current deck was built and whether it uses pre-2004 treated lumber.
- Ask what footing depth your building department requires for frost.
- Plan stair location and snow storage so winter shoveling doesn't damage boards or railings.
- 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.

