How old are homes in Lynnwood, and what does that mean for a deck?
37% of homes in Lynnwood's covered ZIP codes were built in 2000 or later and 8% before 1960; the largest group dates to the 2000s.
The median home in Lynnwood was built around 1991. A deck built with a house of that age is now about 35 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 Snohomish County overall (median 1990). Statewide, the median Washington home was built in 1985. Among the 34 covered Washington communities with Census data, Lynnwood ranks #23 for oldest housing. In these ZIP codes, 8% of homes were built before 1960, 26% between 1960 and 1979, 29% between 1980 and 1999, and 37% since 2000 — the single largest group dates to the 2000s.
| Decade built | Homes | Share |
|---|---|---|
| 2020 or later | 1,380 | 3% |
| 2010s | 7,740 | 17% |
| 2000s | 8,298 | 18% |
| 1990s | 6,765 | 15% |
| 1980s | 6,526 | 14% |
| 1970s | 5,845 | 13% |
| 1960s | 6,251 | 13% |
| 1950s | 2,506 | 5% |
| 1940s | 436 | 1% |
| before 1940 | 731 | 2% |
What does Lynnwood's climate mean for deck construction?
Lynnwood averages about 29 days a year at or below freezing, 3.8 inches of snow and 33.4 inches of precipitation, based on NOAA 1991–2020 normals.
The nearest NOAA climate station with 1991–2020 normals is Everett Snohomish AP, about 3 miles away. It records an average of 29 days a year with a low at or below 32°F — relatively few freezing nights. On roughly 27 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 Lynnwood 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.
Snowfall is light — about 3.8 inches in an average year at Seattle Sand Pt Wsfo — so occasional ice is a bigger concern than snow load. Textured boards and good drainage on stairs help on icy mornings.
Lynnwood sees about 33.4 inches of precipitation a year, with measurable rain or snow (0.1 inch or more) on about 92 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 71°F and only about 1 days a year at 90°F or above — so board color can be chosen mostly on looks.
Which decking material makes the most sense in Lynnwood?
For most Lynnwood homes, composite or well-maintained wood is the strongest starting point.
Budget, upkeep tolerance and sun exposure on your particular lot still decide the final choice between these options.
| Material | How it handles Lynnwood's conditions |
|---|---|
| Pressure-treated pine | Economical; needs regular cleaning and sealing |
| 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 Lynnwood, and how does that shape deck design?
Lynnwood has about 46,478 housing units across its covered ZIP codes. 51% are single-family detached homes, 7% are attached homes such as townhouses and rowhouses, and about 42% are in buildings with two or more units. Roughly 57% of occupied homes are owner-occupied.
The mix of detached homes and attached or multi-unit housing in Lynnwood 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 Lynnwood?
Based on the age of Lynnwood's housing, the largest group of projects is likely to be replacing or rebuilding aging decks.
- Replacement and major repair: about 19,136 homes (41%) 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 9,924 homes (21%) 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 9,120 homes (20%) 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 Lynnwood?
Lynnwood's milder winters — about 29 freezing nights a year — allow construction through most of the year. Spring and fall are still the busiest seasons, so booking early helps.
Do you need a permit to build a deck in Lynnwood?
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 Snohomish County for unincorporated areas.
For Lynnwood, WA, 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 Washington is on our state page; local rules change, so the building department remains the authority.
How does Lynnwood compare with nearby covered areas?
The closest covered area is Mountlake Terrace, about 3.1 miles from the center of Lynnwood's covered ZIPs. Its median home was built in 1973, 18 years earlier than in Lynnwood. The two have a similar share of detached single-family homes (51% vs. 51%). Owner-occupancy is 57% in Lynnwood compared with 57% in Mountlake Terrace. Lynnwood's covered ZIP codes span about 21.1 square miles of land with roughly 46,478 homes — about 2,203 per square mile, a typical suburban density where most homes have usable backyards.
| Area | Distance | Median year built | Covered ZIPs |
|---|---|---|---|
| Mountlake Terrace | 3.1 mi | 1973 | 1 |
| Edmonds | 3.5 mi | 1975 | 2 |
| Bothell | 3.9 mi | 1997 | 3 |
| Mukilteo | 5.4 mi | 1989 | 1 |
| Kenmore | 6.1 mi | 1985 | 1 |
| Everett | 7.1 mi | 1985 | 4 |
How do Lynnwood's covered ZIP codes differ?
| ZIP | Homes | Median year built | Owner-occupied | County |
|---|---|---|---|---|
| 98036 | 17,372 | 1985 | 60% | Snohomish County |
| 98037 | 11,581 | 1985 | 62% | Snohomish County |
| 98087 | 17,525 | 2001 | 52% | Snohomish County |
Deck planning checklist for Lynnwood homeowners
- Confirm your ZIP code is one of the 3 covered Lynnwood ZIPs.
- Find out when your current deck was built and whether it uses pre-2004 treated lumber.
- 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.

