Deck Construction cost in Seattle, WA
A typical deck construction in Seattle, Washington models at $16,200 – $35,700, with a mid point around $23,600. Seattle carries a labour index of 1.24, a material index of 1.06 and a permit index of 1.4 against the national base, in climate zone 4C with a 12 in frost depth. That is a whole-job model — 11 scoped tasks, 27 days elapsed, 21% contractor overhead and profit and 8% contingency — not a per-unit rate multiplied out. Renolume states 100/100 confidence (High confidence) for a standard property here.
Modelled by the Renolume estimating model · engine 2.0.0, data v2026.1 · Last updated . Every figure on this page is produced by the Renolume engine at the stated engine and data version. Nothing is scraped, crowd-sourced or supplied by a contractor, and no figure is edited by hand after the model runs.
What drives deck construction cost in Seattle
Why this job is priced differently in Seattle than anywhere else. Everything below is local: the wage base, the supply chain, the permit regime and the weather the assembly has to survive.
| Local factor | Value used | What it means for your quote |
|---|---|---|
| Labour market | 1.24× national base | Seattle carries high burdened trade rates, driven by sustained regional construction demand and a comparatively small pool of experienced exterior crews. Residential work competes with a steady commercial pipeline for the same labour. |
| Material supply | 1.06× national base | Covers freight distance and local supply depth. It moves less than labour, but it moves. |
| Permit regime | 1.40× national base | Permitting is comparatively demanding and comparatively slow, with meaningful energy-code requirements attaching to replacement work and additional environmental and stormwater review in parts of the metro. |
| Climate exposure | Zone 4C · frost 12 in | Climate zone 4C: a mild marine climate with long damp seasons, few freeze events, modest summer heat and persistent moisture. Frost depth is shallow at roughly 12 inches, so the durability story is moisture and biological growth, not ice. |
| Wage sample quality | measured | A measured wage sample for CBSA 42660, which is why this city page is published and indexed. |
Persistent moisture
Long damp seasons drive moss and organic growth and make drainage detailing the durability decision on every exterior assembly.
Energy code
State requirements set a real performance floor on replacement work, which removes the cheap end of the specification range.
Labour scarcity
High burdened rates and long lead times because experienced exterior crews are in short supply relative to demand.
Site access
Steep lots, mature vegetation and narrow older streets frequently convert mechanised work into hand labour.
Permits, inspections and scheduling in Seattle
Permits, inspections, crew availability and season in Seattle — the part of a project that has nothing to do with the material you pick.
Permitting is comparatively demanding and comparatively slow, with meaningful energy-code requirements attaching to replacement work and additional environmental and stormwater review in parts of the metro.
Modelled permit allowance for this job: $200 – $1,100.
Inspection expectations are strict, with attention to water management, flashing and energy-code compliance documentation.
3 days of inspection wait is modelled inside the 21 days–70 days elapsed window.
Reputable crews book out well ahead. Lead time to start, rather than time on site, is the practical constraint on almost every project here.
There is no hard seasonal cut-off, but the drier months are heavily booked because they are the only reliable window for work that must stay dry. Wet-season scheduling means genuine stand-down days.
2 day(s) of weather buffer are carried for this metro.
Deck Construction in Seattle: Shallow frost depth keeps footings inexpensive, but persistent damp makes species selection, ventilation beneath the deck and drainage the whole durability question.
Planning deck construction in Seattle: what local homeowners should know
Planning guidance written for Seattle specifically — the answers change city by city because the labour market, the code regime, the climate and the access conditions do.
Seattle is expensive for two structural reasons and one regulatory one: burdened labour rates are high, experienced exterior crews are scarce, and the state energy code sets a performance floor that removes the cheapest specification from the table. Frost work is negligible and the climate is gentle, so almost none of the premium is climate severity — it is the price of the labour and the paperwork.
Delay is front-loaded here. Permit review and contractor backlog both run long, so weeks pass before work begins. Once a crew is on site, the wet season is the second mechanism: work that must be kept dry accumulates stand-down days in a way that summer scheduling avoids entirely.
Moisture management, not thermal extremes, decides material life in this climate. Drainage detailing, flashing and ventilation carry the durability outcome, and moss growth on shaded planes is a routine maintenance item rather than a defect. Because there is neither deep cold nor sustained heat, the marginal value of a premium thermal upgrade is smaller here than in a cold metro — spend on water management first.
File early and target the drier months for the physical work. Because queue position is the binding constraint, the useful move is to commit ahead of the season rather than waiting for good weather and joining the same queue as everybody else.
Confirm what your jurisdiction requires on energy performance for the assembly you are replacing, and whether any environmental or stormwater review applies to your lot. Then ask each contractor for a realistic start date rather than a job duration — in this metro the wait is the larger number — and ask how they intend to keep the work dry if it runs into the wet season.
The usual surprise is elapsed time rather than price: months can pass between decision and start. The second is compliance scope, where a straightforward replacement is pulled up to a current performance standard the old assembly never met.
None of this changes the scope of the job — it changes what the job costs and how long it takes here. Model your own deck construction in Seattle to replace these standard-property assumptions with your roof pitch, access, condition and specification, and to raise the confidence score this page reports.
Decking material comparison
Cost, service life, upkeep, efficiency and installation difficulty side by side — the trade-off, not just the price.
| Decking material | Modelled cost | Step up | Rate per sq ft | Elapsed time |
|---|---|---|---|---|
| Pressure-treated pine | $16,000 – $34,800 | baseline | $50 – $109 | 28 days |
| Capped composite | $16,200 – $35,700 | +$500 | $51 – $112 | 27 days |
| Hardwood or PVC | $16,200 – $35,700 | +$500 | $51 – $112 | 27 days |
| Decking material | Service life | Maintenance | Energy | Installation | Planning note |
|---|---|---|---|---|---|
| Pressure-treated pine | 10–15 years for the surface | Highest. Clean and re-seal every one to three years or it greys, checks and splinters. | n/a | Lowest. Universally available and stocked. | Lowest cost today, highest cost over twenty years once upkeep is counted. |
| Capped composite | 25–30 years | Low. Wash only; no sealing cycle. | n/a | Low, but hidden-fastener systems slow installation slightly. | The default choice. Dark boards get notably hot underfoot in full sun. |
| Hardwood or PVC | 25–50 years | Moderate for hardwood (oiling), very low for PVC. | n/a | Highest. Hardwood needs pre-drilling and skilled labour. | Specify for appearance and longevity; confirm fastener and joist spacing requirements up front. |
Cost by size in Seattle, WA
Every row is a separate run of the same model at the same specification — only the size changes. Note how the per sq ft rate falls as the job grows: fixed costs like permits, mobilisation and disposal setup do not scale with size.
| Deck size | Typically | Modelled cost | Rate per sq ft | Elapsed time |
|---|---|---|---|---|
| 10 x 12 ft (120 sq ft) | small landing or grill deck | $9,600 – $21,700 | $80 – $181 | 25 days |
| 12 x 16 ft (192 sq ft) | table for four plus circulation | $12,000 – $26,700 | $62 – $139 | 26 days |
| 16 x 20 ft (320 sq ft) | the most common family deck | $16,200 – $35,700 | $51 – $112 | 27 days |
| 20 x 24 ft (480 sq ft) | dining and lounge zones together | $21,800 – $48,000 | $45 – $100 | 30 days |
| 24 x 30 ft (720 sq ft) | large multi-use deck | $30,400 – $66,500 | $42 – $93 | 33 days |
Why deck construction costs what it does in Seattle compared with other metros
Identical scope, identical specification, priced against each metro's own wage sample. Seattle models above the 11-metro average of $19,800 – $24,200, because of high burdened labour rates, long permit and contractor lead times, and an energy code that sets a specification floor.
| Metro | Modelled cost | Labour index | Elapsed time | Why it sits here |
|---|---|---|---|---|
| Dallas, TX | $13,700 – $29,100 | 0.96 | 27 days | low labour and permit base offset by hail-driven specification upgrades and post-storm market volatility |
| Cleveland, OH | $13,600 – $29,400 | 0.98 | 27 days | labour, material and permit indices all near the national base, with condition risk from older housing stock |
| Houston, TX | $13,800 – $29,300 | 0.93 | 27 days | deep competitive labour pool and the lowest permit burden modelled, offset by wind-resistance scope |
| Atlanta, GA | $13,900 – $29,700 | 0.95 | 27 days | competitive labour, negligible frost work and a moderate permit burden across a highly fragmented jurisdictional map |
| Detroit, MI | $14,100 – $30,300 | 1.02 | 27 days | near-national labour rates carrying genuinely severe cold-climate detailing requirements and older housing stock |
| Denver, CO | $14,800 – $32,200 | 1.06 | 27 days | mid-range labour rates with hail-driven specification requirements and claim-cycle market volatility |
| Philadelphia, PA | $15,200 – $33,300 | 1.14 | 27 days | above-average unionised labour rates combined with attached-housing scope and historic-district constraints |
| Chicago, IL | $15,700 – $34,500 | 1.18 | 27 days | high union labour base plus code-driven cold-climate detailing |
| Seattle, WA (this page) | $16,200 – $35,700 | 1.24 | 27 days | high burdened labour rates, long permit and contractor lead times, and an energy code that sets a specification floor |
| New York, NY | $17,600 – $39,600 | 1.38 | 27 days | logistics, insurance and filing procedure on top of the highest permit index modelled |
| San Francisco, CA | $18,100 – $40,700 | 1.42 | 27 days | highest modelled wage base, slow permit throughput and compliance-driven specification floors |
The spread is not arbitrary. Dallas sits at the bottom of this table because of low labour and permit base offset by hail-driven specification upgrades and post-storm market volatility, while San Francisco sits at the top because of highest modelled wage base, slow permit throughput and compliance-driven specification floors. Scope, task list and specification are identical in every row — what changes between cities is what it costs to staff, supply, permit and access the same job.
See the national deck construction model for the full picture across every modelled metro, or read how the regional indices are built.
What is actually in the job
The task list below is the same in every city; what changes in Seattle is what it costs to staff, supply, permit and access — high burdened labour rates, long permit and contractor lead times, and an energy code that sets a specification floor.
Labour $3,900 – $7,800 · materials $9,200 – $15,700 · other costs $200 – $1,500 · overhead and profit $2,000 – $7,000 · contingency $900 – $3,800. 80.5 modelled labour hours across 3 trades.
- Install decking boards$4,600 – $7,300
- Frame beams, joists and blocking$2,800 – $5,500
- Install guardrail system$2,300 – $4,200
- Form, pour and set footings and posts$900 – $1,900
- Build stairs and handrail$800 – $1,600
Other costs most quotes omit
- Building permit$200 – $1,100
- Footing and final inspection fees$0 – $300
Regional movement: labour index 1.24 · material index 1.06 · permit index 1.4. Labour rates derived from published wage data for Seattle, WA (measured).
How long deck construction takes in Seattle
6.3 days of active work, 13 days of waiting (permits, inspections, weather), and material lead time of 7 days–28 days.
- Layout, permit & demolition0.5 days
- Excavation & footings1.1 days + 5 days wait
- Framing1.5 days + 3 days wait
- Decking1.6 days
- Railing & stairs1.1 days
- Finishing & inspection0.5 days + 3 days wait
Seattle timelines are dominated by what happens before the crew arrives — permit review and backlog — with wet-season stand-down days as the second factor.
Why this number
12 named conditions can change this estimate. 4 already apply to the standard case, and each one is shown with its cause and its effect. Which of them fire in Seattle is shaped by local conditions — see the Seattle planning guidance above.
Guardrail required above 30 in
- Adds “Install guardrail system” to the scope
- A guardrail is required where the walking surface is more than 30 in above grade.
Stairs required
- Adds “Build stairs and handrail” to the scope
Attached deck
- Ledger flashing is the most common cause of deck failure; insist on inspection before decking is laid.
Hidden fasteners on composite
- Adds “Hidden fastener clip system” to the scope
- Increases labour on Install decking boards by 22%
- Guardrail required above 30 in
- Elevated deck
- Stairs required
- Rock excavation
- Clay soil
- Deep frost line
- Attached deck
- Freestanding deck
- Existing deck removal
- Hidden fasteners on composite
- Pressure-treated finishing
- Lighting selected
Confidence score: 100/100 (High confidence)
Renolume publishes how much to trust the number instead of hiding the uncertainty. This page scores a standard property; answering the planner questions raises the score because the model has more to work with. Wage data is measured and reliable. What the model cannot see is your jurisdiction's specific energy or environmental review requirements, which can raise the specification above the modelled default.
- Location precisionmeasured20/20
- Dimensions supplied3/325/25
- Existing-condition information3/320/20
- Material & option selections6/615/15
- Structural / utility / concealed risknone flagged20/20
How this estimate is produced
No contractor supplies these prices, no figure is scraped, and no number is crowd-sourced. Here is the whole chain.
| Step | What happens | Why it matters to you |
|---|---|---|
| 1. Scope | A fixed task library breaks the job into discrete tasks with a trade, a crew size and a productivity rate. This job models 80.5 labour hours across 3 trades. | Nothing is priced that is not described. You can see every task and argue with any of them. |
| 2. Labour | Hours are priced against published government occupational wage data, burdened for payroll costs and scaled to Seattle, Washington by a labour index of 1.24. | The regional difference is an index you can see, not a guess folded into a national average. |
| 3. Materials | Quantities are derived from your inputs with waste factors, then priced at the selected specification and scaled by a material index of 1.06. | Changing specification changes the material line only — the labour model does not silently move. |
| 4. Other costs | Permits, disposal, protection and equipment, with a permit fee index of 1.4. | These are the lines most quotes leave out and most homeowners discover late. |
| 5. Overhead and contingency | 21% contractor overhead and profit, then 8% contingency for conditions nobody can see before the job is opened up. | A real business has to cover both. Estimates that omit them are structurally too low. |
| 6. Confidence | The model scores how much it actually knows about your property and widens the displayed range when it knows less. | You are told how much to trust the number instead of being given false precision. |
Engine version 2.0.0, data version v2026.1, effective 2026-04-01. Full methodology · How the confidence score works
Why two honest quotes can differ this much
Modelled spread on this job is $16,200 – $35,700. Real quotes often spread wider, and it is rarely because one contractor is dishonest.
| Reason | What it looks like on the quote |
|---|---|
| Different scope | One bid includes disposal, permits and finishing; the other assumes you handle them. Same headline job, different work. |
| Different specification | Grade of new deck components — the accessories, not the headline product — is where most silent savings are made. |
| Different risk appetite | A firm carrying a real contingency prices higher and change-orders less. A firm carrying none does the reverse. |
| Different overhead | Licensed and insured crews with warranty support and office staff cost more to run than a truck and two people. |
| Different backlog | A busy contractor prices to be worth interrupting the schedule. The same firm bids differently in the off season. |
| Different assumptions about the unknown | Whoever assumes the least concealed damage looks cheapest on paper and is the most likely to change-order. |
The practical defence is to compare on scope lines rather than totals. Use the breakdown above as the checklist, and ask any bidder missing a line whether it is excluded or simply unpriced.
Repair or replace?
The decision before the budget. Renolume has no reason to push you toward the larger job.
| What you are seeing | What it usually means |
|---|---|
| Surface boards are worn but framing is sound | Re-deck only. Keeping the frame and replacing the surface is far cheaper than a full rebuild. |
| Posts or joists are soft at the ground or the ledger | Replace. Structural rot cannot be surfaced over. |
| Ledger has no visible flashing | Investigate immediately. This is a safety issue, not a cosmetic one. |
| Deck is a different size than you now need | Rebuild. Extending an existing frame rarely costs less than building right. |
Planning a new deck
The parts of a new deck that a cost table cannot tell you.
Most attached decks are permitted work with a footing inspection before concrete and a framing inspection before decking. Those two hold points, not the carpentry, are what stretch a deck project across weeks.
Footings must reach below the local frost line. In a cold-climate metro that can mean four feet of excavation per pier; in a warm one, a fraction of that. Same deck, materially different groundwork.
Terms on your quote, defined
The handful of terms that appear on every quote and change what you are comparing.
- Ledger
- The board attaching the deck to the house. Bad ledger flashing is the leading cause of deck collapse and of wall rot behind the deck.
- Footing
- The concrete pier carrying each post, taken below the local frost line. Frost depth is climate-set and drives excavation cost.
- Guardrail trigger
- Decks above roughly 30 in from grade require a code-compliant guardrail. The height threshold changes the price step, not the deck size.
- Joist spacing
- Composite and diagonal board layouts often require tighter joist spacing than pressure-treated, which adds framing before any decking is laid.
DIY versus contractor
Savings are labour only — materials, disposal and permits do not change.
You could take on
- Excavate footings (advanced)
- Install decking boards (moderate)
- Hidden fastener clip system (moderate)
- Fascia, skirting and trim (moderate)
Leave to a licensed contractor
- Layout, string lines and permit coordination — Licensed or code-regulated work
- Form, pour and set footings and posts — Structural footings and inspection sign-off
- Install ledger board and flashing — Primary structural connection to the house
- Frame beams, joists and blocking — Structural framing
- Install guardrail system — Guardrail load requirements
- Build stairs and handrail — Rise/run code compliance
- Punch list and final inspection — Licensed or code-regulated work
Owner-performed work is constrained by compliance documentation and inspection scrutiny, and moisture detailing is the least forgiving thing to get wrong in this climate.
Model your own deck construction in Seattle
Everything above prices a standard property. Your house is not a standard property, and the difference is usually larger than the difference between cities. The deck construction planner runs the same engine on your inputs and returns a cost range, an itemised scope, a phased timeline, Good/Better/Best options and a confidence score that rises as you answer.
- Size, condition and access replace the standard-property defaults behind the $16,200 – $35,700 range on this page.
- 12 named conditions are re-tested against your answers instead of assumed away — each one shown with its cause and its effect.
- The confidence score moves off 100/100, because the model is working from your inputs rather than Seattle averages.
- Local context is carried through: Confirm what your jurisdiction requires on energy performance for the assembly you are replacing, and whether any environmental or stormwater review applies to your lot.
Open the deck construction planner for Seattle — it takes a few minutes, nothing is emailed to a contractor, and you can save and compare scenarios side by side afterwards.
Key takeaways
- Deck construction in Seattle, WA models at $16,200 – $35,700, mid point $23,600 at the Better specification.
- Expect 21 days to 70 days elapsed, of which only 6.3 days is active work.
- The model states 100/100 confidence for a standard property, and 12 named conditions can move the number.
- Seattle prices differently from other metros because of high burdened labour rates, long permit and contractor lead times, and an energy code that sets a specification floor.
- 21% contractor overhead and profit and 8% contingency are inside the range — a quote without them is not cheaper, it is incomplete.
- Framing and footings, not decking boards, are the majority of a deck budget.
- Height above grade sets whether guardrails are required and is a genuine price step.
- Pressure-treated is cheapest to build and most expensive to own.
- If the frame is sound, re-decking beats rebuilding by a wide margin.
Questions homeowners ask before hiring
How much does a deck construction cost in Seattle?
A deck construction on a standard property in Seattle, Washington models at $16,200 – $35,700 at the Better specification, with a mid point around $23,600. That figure is a whole-job model — labour, materials, 2 other cost lines, 21% contractor overhead and profit and 8% contingency — not a per-unit line item multiplied out.
Which material makes the most sense in Seattle?
In Seattle the same scope models at $16,000 – $34,800 with pressure-treated pine and $16,200 – $35,700 with hardwood or pvc, so material is the largest choice you control on this project. Shallow frost depth keeps footings inexpensive, but persistent damp makes species selection, ventilation beneath the deck and drainage the whole durability question. This page compares every modelled option side by side; each material has its own page setting out service life, upkeep and the cases where it is the wrong choice.
Why does a deck construction cost more or less in Seattle than the national average?
Three published indices explain almost all of it: a labour index of 1.24 against the national wage base, a material index of 1.06 covering freight and local supply, and a permit fee index of 1.4. Seattle carries high burdened trade rates, driven by sustained regional construction demand and a comparatively small pool of experienced exterior crews. Residential work competes with a steady commercial pipeline for the same labour. Nothing about the job itself changes between cities — only what it costs to staff, supply and permit it.
Do I need a permit for a deck construction in Seattle?
Permitting is comparatively demanding and comparatively slow, with meaningful energy-code requirements attaching to replacement work and additional environmental and stormwater review in parts of the metro. A permit line is modelled into this estimate at $200 – $1,100, scaled by the Seattle permit fee index of 1.4. Treat it as a budgeted allowance and confirm the exact requirement with your local building department before work starts — an unpermitted job can create problems at resale.
What will the inspector check in Seattle?
Inspection expectations are strict, with attention to water management, flashing and energy-code compliance documentation. Renolume models 3 days of inspection wait inside the 27 days elapsed timeline, because the waiting — not the inspection itself — is what shows up on your calendar.
How hard is it to get a good contractor in Seattle?
Reputable crews book out well ahead. Lead time to start, rather than time on site, is the practical constraint on almost every project here. Whatever the local market, compare bids on scope lines rather than on the total: this page lists 11 modelled tasks and 2 other cost lines, and a bid that is missing several of them is not cheaper, it is incomplete.
When is the best time of year to schedule a deck construction in Seattle?
There is no hard seasonal cut-off, but the drier months are heavily booked because they are the only reliable window for work that must stay dry. Wet-season scheduling means genuine stand-down days. Renolume carries 2 day(s) of weather buffer for this metro inside the modelled elapsed window of 21 days to 70 days. Off-peak scheduling more often shortens lead time than it lowers price.
How long does a deck construction take in Seattle?
Renolume models 6.3 days of active work and 13 days of waiting — permits, inspections, material lead time and weather buffer — for a total elapsed window of 21 days to 70 days. Crews on site is the short part; the calendar is dominated by what happens between phases.
What are the hidden costs of a deck construction in Seattle?
The costs most quotes leave out are already in this model: Footing and final inspection fees ($0 – $300). On top of that, 8% contingency is carried for conditions nobody can see until the job is opened up, and these are explicitly excluded: Retaining walls, grading or drainage work; Roof structures, pergolas and screening; Hot tub structural reinforcement.
Can I do a deck construction myself, or do I need a contractor?
Renolume models $0 to $0 of labour that a capable owner could take on — typically Excavate footings, Install decking boards, Hidden fastener clip system. These stay with a licensed contractor: Layout, string lines and permit coordination, Form, pour and set footings and posts, Install ledger board and flashing, because of code, insurance or safety exposure. DIY savings are labour only; materials, disposal and permits do not change.
How deep do deck footings need to go in Seattle?
Below the local frost line, which is set by climate rather than by design. Shallow frost depth keeps footings inexpensive, but persistent damp makes species selection, ventilation beneath the deck and drainage the whole durability question. Renolume models the excavation accordingly, and the footing inspection hold point — not the carpentry — is normally what stretches a deck project across weeks. Total modelled elapsed window: 21 days to 70 days.
What local factors change this number in Seattle?
Persistent moisture: Long damp seasons drive moss and organic growth and make drainage detailing the durability decision on every exterior assembly. Energy code: State requirements set a real performance floor on replacement work, which removes the cheap end of the specification range. Labour scarcity: High burdened rates and long lead times because experienced exterior crews are in short supply relative to demand. Site access: Steep lots, mature vegetation and narrow older streets frequently convert mechanised work into hand labour. All three published indices behind those factors are stated on this page — labour 1.24, material 1.06, permit 1.4 — and 2 day(s) of local weather buffer are carried in the timeline. Site access, storey height and existing conditions are modelled separately in the planner because they are property-specific, not city-specific.
Is it worth repairing instead of a full deck construction?
A targeted repair is normally worth it when the failure is isolated and the rest of the assembly still has service life. Once the damaged share approaches roughly a third of the whole, repair economics collapse — you pay set-up, access and disposal twice, and the two halves age differently. Model the full job at $16,200 – $35,700 first, then compare a quoted repair against it rather than against a national average.
How accurate is this estimate for Seattle?
This page carries a confidence score of 100/100 (High confidence) for a generic property, because it assumes a standard case rather than yours. Wage data for Seattle is measured sample quality (CBSA 42660), which is one of the 5 stated factors behind the score. Answering the planner questions raises it, because the model then has real inputs instead of defaults.
Where does the Seattle cost data come from?
Labour hours come from a fixed task library, wage rates from published government wage data at measured sample quality for Seattle, and regional movement from a labour index of 1.24, a material index of 1.06 and a permit index of 1.4. Nothing is scraped, crowd-sourced or supplied by a contractor. Data version v2026.1, effective 2026-04-01.
Assumptions, exclusions and data sources
These are the model's standing assumptions for a Seattle property. Where local practice overrides them — permits, inspections, season — that is set out in the Seattle sections above.
- Footings are assumed at one per 48 sq ft of deck area with a minimum of four.
- Footing depth follows the local frost line recorded for your region.
- Pressure-treated decks require re-staining every 2–3 years; that recurring cost is shown separately, not in the build total.
- Retaining walls, grading or drainage work
- Roof structures, pergolas and screening
- Hot tub structural reinforcement
- Utility relocation beneath the deck footprint
- Published government occupational wage data for Seattle (measured sample quality, CBSA 42660), scaled by a labour index of 1.24.
- A fixed task and productivity library — 80.5 modelled hours across 3 trades — rather than contractor-supplied prices.
- Regional material index 1.06 and permit fee index 1.4 for Washington.
- Engine version 2.0.0, data version v2026.1, effective 2026-04-01. Nothing is scraped, crowd-sourced or quoted by a contractor.
Get this priced for your actual house
Answer six questions and the range narrows to your property, your access, your existing conditions.
Planning estimate only. This is not a quote, bid or appraisal. Ranges reflect typical market conditions for the stated data version and do not account for site-specific concealed conditions, local code interpretation or contractor availability. Always obtain written bids. Data version v2026.1. Last updated . Methodology.