{
  "dataset": {
    "id": "seattle-crawlspace-cost-index",
    "title": "Seattle Crawlspace Cost Index",
    "description": "Modeled 2026 cost ranges for nine crawl space, basement and foundation services in the Seattle metro, before Washington sales tax, published with the reference project each range prices, the scope each one includes and excludes, the data basis behind it, how it was derived, and the date it was last reviewed. Every range is an editorial model estimate adjusted from this publisher’s Portland-metro model by a published price index, not a sample of collected contractor quotes.",
    "publisher": "Seattle Crawlspace Pros",
    "publisher_url": "https://seattlecrawlspacepros.com/",
    "url": "https://seattlecrawlspacepros.com/data/seattle-crawlspace-cost-index/",
    "version": "2026-11-10",
    "last_reviewed": "2026-11-10",
    "next_review": "2027-02-01",
    "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
    "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
    "derivation_inputs": {
      "base_model": "Portland-metro editorial model (same publisher)",
      "factor": 1.05418,
      "index": "Bureau of Economic Analysis all-items Regional Price Parities",
      "index_year": 2024,
      "seattle_parity": 111.133,
      "portland_parity": 105.421,
      "rounded_to_usd": 25,
      "quotes_collected": 0
    },
    "sales_tax_included": false,
    "sales_tax_note": "Washington retail sales tax, which applies to the full contract price, labor and materials together, at the rate for the job site: 10.55% in Seattle from October 1 to December 31, 2026. Every range here is before tax.",
    "temporal_coverage": "2026-01-01/..",
    "currency": "USD",
    "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
    "universal_exclusions": [
      "Washington retail sales tax, which applies to the full contract price, labor and materials together, at the rate for the job site: 10.55% in Seattle from October 1 to December 31, 2026. Every range here is before tax",
      "Permit fees, which vary by jurisdiction and are usually billed at cost",
      "Structural repair of framing found to be rotten once the space is opened up",
      "Asbestos or lead abatement, which is separate work no range here prices",
      "Electrical service upgrades where an existing panel cannot carry new equipment",
      "Landscape or hardscape restoration after exterior excavation"
    ],
    "methodology_url": "https://seattlecrawlspacepros.com/cost/methodology/",
    "corrections_url": "https://seattlecrawlspacepros.com/contact/",
    "license": "These figures may be quoted, charted and republished with attribution to Seattle Crawlspace Pros and a link to the cost index page. Please state the review date alongside any figure, because the ranges are revised.",
    "citation": "Seattle Crawlspace Pros. \"Seattle Crawlspace Cost Index.\" Updated November 2026. SeattleCrawlspacePros.com.",
    "data_basis_definitions": [
      {
        "basis": "MEASURED",
        "label": "Measured",
        "definition": "A value reported directly by the authority that holds it, or read out of a legitimate published dataset without alteration. A code requirement quoted from the adopted code, a sales tax rate read off the state’s rate table, a rainfall total from the National Weather Service.",
        "used_here": "No row of the cost index is measured, and no published price on this site is. Measured values do appear around the prices: the Washington sales tax rates this site quotes are read from the Department of Revenue’s rate table, the two regional price parities and the two wage figures behind the adjustment are read from the Bureau of Economic Analysis and the Bureau of Labor Statistics, and code requirements are quoted from the adopted code. The climate and housing dataset states the basis of each of its own columns."
      },
      {
        "basis": "DERIVED",
        "label": "Derived",
        "definition": "A value calculated from measured inputs by a stated formula, where both the inputs and the formula are published so the result can be recomputed independently.",
        "used_here": "No row of the cost index is derived. The adjustment factor is derived: 1.05418 is one published price parity divided by another (111.133 / 105.421), and anyone can recompute it. But the thing it multiplies is an editorial estimate, and a calculation performed on an estimate returns an estimate. The same holds for the cost calculator, which adjusts a modeled base range and so returns a modeled range."
      },
      {
        "basis": "MODELED",
        "label": "Modeled",
        "definition": "An editorial estimate: a considered judgement about what a defined scope of work costs in a market, published with its assumptions and its derivation. It is not a measurement of that market, and adjusting it by a published index does not make it one.",
        "used_here": "Every row of the cost index. Each range is this publisher’s Portland-metro editorial model multiplied by 1.05418 and rounded to the nearest $25, before sales tax. This is the honest label for what this dataset is, and it is the reason the ranges are published as bands rather than as point estimates."
      },
      {
        "basis": "OBSERVED_QUOTE_DATA",
        "label": "Observed quote data",
        "definition": "A range computed from a sample of real quotes issued to real homeowners, published with its sample size, its median, and the dates the quotes were issued. Reserved for future use under a stated threshold of 30 quoted projects per service.",
        "used_here": "Nothing. This site does not hold a database of Seattle-area contractor quotes and does not present one. The classification is defined here so that the day such data exists it lands in a slot whose meaning was fixed before anyone had an interest in stretching it."
      }
    ],
    "caveat": "Every range is a modeled editorial estimate for the stated reference project, adjusted to the stated market by a published price index and quoted before sales tax. It is not a bid, not an offer, not an average of collected quotes, and no contractor is bound by it."
  },
  "fields": [
    {
      "name": "service_slug",
      "type": "string",
      "description": "Stable machine identifier for the service. Safe to join on; it does not change when a service is renamed for display."
    },
    {
      "name": "service",
      "type": "string",
      "description": "Display name of the service."
    },
    {
      "name": "typical_low_usd",
      "type": "integer",
      "description": "Low end of the typical modeled range, in whole US dollars before sales tax, for the reference project."
    },
    {
      "name": "typical_high_usd",
      "type": "integer",
      "description": "High end of the typical modeled range, in whole US dollars before sales tax, for the reference project."
    },
    {
      "name": "premium_low_usd",
      "type": "integer",
      "description": "Low end of the premium band, before sales tax, where the service has one. Empty where it does not. The premium band prices a different and larger scope, not a more expensive contractor."
    },
    {
      "name": "premium_high_usd",
      "type": "integer",
      "description": "High end of the premium band, before sales tax, where the service has one. Empty where it does not."
    },
    {
      "name": "premium_trigger",
      "type": "string",
      "description": "The specific conditions that move a project from the typical band into the premium band."
    },
    {
      "name": "data_basis",
      "type": "enum",
      "values": [
        "MEASURED",
        "DERIVED",
        "MODELED",
        "OBSERVED_QUOTE_DATA"
      ],
      "description": "How the range was arrived at. Every row is MODELED. See the definitions published alongside the dataset before reusing this field."
    },
    {
      "name": "derivation",
      "type": "string",
      "description": "How the figures in the row were produced: the base model, the index it was multiplied by with both index values, the rounding, and the statement that no quotes were collected. Identical on every row."
    },
    {
      "name": "sales_tax_included",
      "type": "boolean",
      "description": "Whether the dollar fields include Washington retail sales tax. false on every row: the tax applies to the full contract price at the job-site rate and is not in any range."
    },
    {
      "name": "geography",
      "type": "string",
      "description": "The market the range describes. Identical on every row. The figures were adjusted to this market from another by a price index; they were not measured in it."
    },
    {
      "name": "reference_project",
      "type": "string",
      "description": "The specific project the range prices. A range is not interpretable without it."
    },
    {
      "name": "includes",
      "type": "string[]",
      "description": "Line items a quote in the typical range normally covers. Pipe-separated in CSV, an array in JSON."
    },
    {
      "name": "excludes",
      "type": "string[]",
      "description": "Line items normally billed separately and not covered by the typical range. Pipe-separated in CSV, an array in JSON."
    },
    {
      "name": "sample_size",
      "type": "integer",
      "description": "Number of real quoted projects behind the range. Empty on every row, because no row rests on observed quote data. A row may not be labelled OBSERVED_QUOTE_DATA below 30 quoted projects."
    },
    {
      "name": "sample_median_usd",
      "type": "integer",
      "description": "Median of the quote sample, in whole US dollars. Empty on every row today."
    },
    {
      "name": "quotes_from",
      "type": "date",
      "description": "Earliest issue date in the quote sample, ISO 8601. Empty on every row today."
    },
    {
      "name": "quotes_to",
      "type": "date",
      "description": "Latest issue date in the quote sample, ISO 8601. Empty on every row today."
    },
    {
      "name": "last_reviewed",
      "type": "date",
      "description": "When the range was last produced or re-examined, ISO 8601. Moves only when someone actually re-examined it, never on an unrelated deploy."
    },
    {
      "name": "service_url",
      "type": "url",
      "description": "Absolute URL of the page describing the work."
    },
    {
      "name": "cost_url",
      "type": "url",
      "description": "Absolute URL of the dedicated cost breakdown page, where the service has one. Empty where it does not."
    }
  ],
  "records": [
    {
      "service_slug": "vapor-barrier",
      "service": "Vapor Barrier Installation",
      "typical_low_usd": 3400,
      "typical_high_usd": 4675,
      "premium_low_usd": 4925,
      "premium_high_usd": 6725,
      "premium_trigger": "Premium 20-mil cross-laminated barrier with wall coverage and double-sealed seams ($4,925–$6,725 total)",
      "data_basis": "MODELED",
      "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
      "sales_tax_included": false,
      "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
      "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
      "includes": [
        "Removal and disposal of the existing barrier where one is present",
        "A code-compliant reinforced polyethylene sheet across the full soil floor",
        "Seams lapped and sealed, and edges run up the stem wall and fastened",
        "Sealing around piers and penetrations"
      ],
      "excludes": [
        "Any drainage work — a barrier is moisture control, not water management",
        "Insulation removal or replacement",
        "A dehumidifier or any mechanical conditioning",
        "Sealing the foundation vents, which converts this into a closed-crawl scope"
      ],
      "sample_size": null,
      "sample_median_usd": null,
      "quotes_from": null,
      "quotes_to": null,
      "last_reviewed": "2026-11-10",
      "service_url": "https://seattlecrawlspacepros.com/solutions/crawl-space-repair/vapor-barrier/",
      "cost_url": "https://seattlecrawlspacepros.com/cost/vapor-barrier/"
    },
    {
      "service_slug": "drainage",
      "service": "Crawl Space Drainage",
      "typical_low_usd": 4025,
      "typical_high_usd": 7175,
      "premium_low_usd": 7625,
      "premium_high_usd": 14325,
      "premium_trigger": "Complex hillside systems with multiple interceptors and long discharge runs ($7,625–$14,325)",
      "data_basis": "MODELED",
      "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
      "sales_tax_included": false,
      "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
      "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
      "includes": [
        "Trenching an interior perimeter drain and setting pipe in drain rock",
        "A sump basin, pump and discharge plumbing to daylight or an approved point",
        "Backfill and site cleanup inside the crawl space"
      ],
      "excludes": [
        "A vapor barrier over the soil, quoted separately",
        "Exterior downspout rework or regrading, typically $700 to $2,250 more",
        "Curtain drains on hillside lots, typically $2,250 to $5,375 more",
        "Restoring landscaping disturbed by any exterior portion of the work"
      ],
      "sample_size": null,
      "sample_median_usd": null,
      "quotes_from": null,
      "quotes_to": null,
      "last_reviewed": "2026-11-10",
      "service_url": "https://seattlecrawlspacepros.com/solutions/crawl-space-repair/drainage/",
      "cost_url": null
    },
    {
      "service_slug": "waterproofing",
      "service": "Crawl Space Waterproofing",
      "typical_low_usd": 4025,
      "typical_high_usd": 7175,
      "premium_low_usd": 7625,
      "premium_high_usd": 10650,
      "premium_trigger": "Hillside lots with long discharge runs or significant existing flooding ($7,625–$10,650)",
      "data_basis": "MODELED",
      "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
      "sales_tax_included": false,
      "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
      "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
      "includes": [
        "An interior perimeter drain with sump basin, pump and discharge",
        "Crack repair on the foundation wall where cracks are the entry path",
        "A vapor barrier over the soil floor"
      ],
      "excludes": [
        "Exterior excavation and membrane, which is foundation waterproofing",
        "Insulation replacement",
        "Mold remediation of what the water already caused"
      ],
      "sample_size": null,
      "sample_median_usd": null,
      "quotes_from": null,
      "quotes_to": null,
      "last_reviewed": "2026-11-10",
      "service_url": "https://seattlecrawlspacepros.com/solutions/crawl-space-repair/waterproofing/",
      "cost_url": "https://seattlecrawlspacepros.com/cost/waterproofing/"
    },
    {
      "service_slug": "sump-pump",
      "service": "Sump Pump Installation",
      "typical_low_usd": 1600,
      "typical_high_usd": 3125,
      "premium_low_usd": 2250,
      "premium_high_usd": 4025,
      "premium_trigger": "Battery backup pump ($2,250–$4,025) or full drainage system with sump ($4,025–$7,175)",
      "data_basis": "MODELED",
      "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
      "sales_tax_included": false,
      "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
      "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
      "includes": [
        "The pump, basin and lid",
        "Discharge plumbing to an approved discharge point",
        "Electrical connection to an existing suitable circuit"
      ],
      "excludes": [
        "A perimeter drain to feed the basin — a pump alone only removes water that reaches it",
        "A battery backup pump, which brings the total to $2,250 to $4,025",
        "A new dedicated circuit where the existing electrical cannot carry the pump"
      ],
      "sample_size": null,
      "sample_median_usd": null,
      "quotes_from": null,
      "quotes_to": null,
      "last_reviewed": "2026-11-10",
      "service_url": "https://seattlecrawlspacepros.com/solutions/crawl-space-repair/sump-pump/",
      "cost_url": "https://seattlecrawlspacepros.com/cost/sump-pump/"
    },
    {
      "service_slug": "encapsulation",
      "service": "Crawl Space Encapsulation",
      "typical_low_usd": 10650,
      "typical_high_usd": 13000,
      "premium_low_usd": 15675,
      "premium_high_usd": 21500,
      "premium_trigger": "Dehumidifier, closed-cell rim joist foam, and full premium scope ($15,675–$21,500)",
      "data_basis": "MODELED",
      "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
      "sales_tax_included": false,
      "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
      "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
      "includes": [
        "A heavy liner across the soil floor and up the foundation walls, sealed and fastened",
        "Sealing the foundation vents and the crawl space access",
        "Sealing seams, piers and penetrations"
      ],
      "excludes": [
        "Drainage, if water actively enters the space — this comes first and is priced separately",
        "A dehumidifier and its electrical work, $1,350 to $2,700 more",
        "Closed-cell foam at the rim joists, $1,075 to $2,150 more",
        "A radon vent system or continuous exhaust ventilation, where the permit for a sealed crawl space calls for one",
        "Floor insulation, which is the part a utility rebate may apply to"
      ],
      "sample_size": null,
      "sample_median_usd": null,
      "quotes_from": null,
      "quotes_to": null,
      "last_reviewed": "2026-11-10",
      "service_url": "https://seattlecrawlspacepros.com/solutions/crawl-space-repair/encapsulation/",
      "cost_url": "https://seattlecrawlspacepros.com/cost/encapsulation/"
    },
    {
      "service_slug": "insulation-replacement",
      "service": "Insulation Replacement",
      "typical_low_usd": 2500,
      "typical_high_usd": 5825,
      "premium_low_usd": 4025,
      "premium_high_usd": 8075,
      "premium_trigger": "Spray foam on the foundation walls instead of the floor, which Washington’s energy code gives no crawl space wall path and PSE’s rebate does not cover ($4,025–$8,075)",
      "data_basis": "MODELED",
      "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
      "sales_tax_included": false,
      "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
      "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
      "includes": [
        "Removal and disposal of existing batt insulation",
        "New floor insulation installed to current code R-value",
        "Air sealing at the rim joists"
      ],
      "excludes": [
        "A vapor barrier, unless the quote names it",
        "Rodent exclusion or sanitizing where droppings are present",
        "Mold remediation of contaminated framing",
        "The moisture fix that ruined the last insulation, without which this repeats"
      ],
      "sample_size": null,
      "sample_median_usd": null,
      "quotes_from": null,
      "quotes_to": null,
      "last_reviewed": "2026-11-10",
      "service_url": "https://seattlecrawlspacepros.com/solutions/crawl-space-repair/insulation-replacement/",
      "cost_url": null
    },
    {
      "service_slug": "mold-remediation",
      "service": "Mold Remediation",
      "typical_low_usd": 1600,
      "typical_high_usd": 4025,
      "premium_low_usd": 5825,
      "premium_high_usd": 10650,
      "premium_trigger": "Full-area remediation paired with encapsulation or drainage to fix the source ($5,825–$10,650 combined)",
      "data_basis": "MODELED",
      "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
      "sales_tax_included": false,
      "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
      "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
      "includes": [
        "Containment and controlled removal of affected materials",
        "HEPA vacuuming and antimicrobial treatment of framing",
        "Disposal of contaminated material"
      ],
      "excludes": [
        "The moisture source — remediation without it is a repeating expense",
        "Post-remediation air sampling, $275 to $700",
        "Wood rot repair on affected framing, $375 to $1,350 per location",
        "Any testing done before work begins"
      ],
      "sample_size": null,
      "sample_median_usd": null,
      "quotes_from": null,
      "quotes_to": null,
      "last_reviewed": "2026-11-10",
      "service_url": "https://seattlecrawlspacepros.com/solutions/crawl-space-repair/mold-remediation/",
      "cost_url": null
    },
    {
      "service_slug": "basement-waterproofing",
      "service": "Basement Waterproofing",
      "typical_low_usd": 7625,
      "typical_high_usd": 16125,
      "premium_low_usd": 17925,
      "premium_high_usd": 26875,
      "premium_trigger": "Dual sumps, large dehumidifiers, and finish replacement ($17,925–$26,875)",
      "data_basis": "MODELED",
      "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
      "sales_tax_included": false,
      "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
      "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
      "includes": [
        "An interior perimeter drain and sump with battery backup",
        "Crack injection on the foundation walls",
        "A basic wall membrane"
      ],
      "excludes": [
        "Exterior excavation, which is a different and much larger scope",
        "Replacing finished walls, flooring or fixtures removed to reach the foundation",
        "A dehumidifier sized for a finished basement"
      ],
      "sample_size": null,
      "sample_median_usd": null,
      "quotes_from": null,
      "quotes_to": null,
      "last_reviewed": "2026-11-10",
      "service_url": "https://seattlecrawlspacepros.com/solutions/basement-waterproofing/",
      "cost_url": null
    },
    {
      "service_slug": "foundation-waterproofing",
      "service": "Foundation Waterproofing",
      "typical_low_usd": 15825,
      "typical_high_usd": 40050,
      "premium_low_usd": null,
      "premium_high_usd": null,
      "premium_trigger": "Hillside lots with shoring, deep excavation, or difficult access (beyond $40,050)",
      "data_basis": "MODELED",
      "derivation": "Portland-metro editorial model x 1.05418 (BEA 2024 all-items Regional Price Parities, Seattle-Tacoma-Bellevue 111.133 / Portland-Vancouver-Hillsboro 105.421), rounded to the nearest $25, before Washington retail sales tax. No contractor quotes were collected for the Seattle market.",
      "sales_tax_included": false,
      "geography": "Seattle metropolitan area in King County and south Snohomish County, Washington, United States",
      "reference_project": "1,200 to 1,500 square feet of crawl space floor, damp but without standing water at the time of the quote, a standard exterior or interior hatch with roughly 3 feet of working clearance, on a single-family home on a continuous perimeter foundation, in the Seattle metro (King County and south Snohomish County), priced in 2026 dollars before sales tax.",
      "includes": [
        "Full-perimeter excavation to the footing",
        "Exterior waterproofing membrane and drainage board",
        "A footing drain with discharge",
        "Backfill"
      ],
      "excludes": [
        "Landscape, hardscape, deck or fence restoration",
        "Shoring or engineering where excavation depth or soil requires it",
        "Any interior work — this is an exterior scope",
        "Utility relocation encountered during excavation"
      ],
      "sample_size": null,
      "sample_median_usd": null,
      "quotes_from": null,
      "quotes_to": null,
      "last_reviewed": "2026-11-10",
      "service_url": "https://seattlecrawlspacepros.com/solutions/foundation-waterproofing/",
      "cost_url": null
    }
  ]
}