King County

Home permits and project costs in Seattle, WA

SDCI review timelines, seismic detailing and energy-code requirements add meaningful cost and schedule to structural and envelope work.

Verified August 2026

Local cost index

+26%

vs national average

Permit fee index

+35%

vs national baseline

Population

755,078

Homeownership

46%

Do you need a permit in Seattle?

For most structural work, yes

Seattle enforces washington state residential code, based on the irc, plus the state energy code through King County. Roofing, electrical, plumbing, structural, pools and most exterior additions require a permit and inspection. Cosmetic work — paint, flooring, cabinet swaps — generally does not.

Project costs in Seattle

National baselines adjusted by the local labor and materials index.

Project	Typical cost	Permit	Deep pages
Roof Replacement	$13,300 – $45,000	required	Cost·Permit
AC Replacement	$6,900 – $20,500	required	Cost·Permit
Fence Installation	$3,200 – $14,500	usually required	Cost·Permit
Water Heater Replacement	$1,600 – $7,300	required	Cost·Permit
Pool Installation	$52,200 – $157,900	required	Cost·Permit
Window Replacement	$10,200 – $46,200	required	Cost·Permit
Electrical Panel Replacement	$2,600 – $9,300	required	Cost·Permit
Generator Installation	$8,800 – $29,900	required	Cost·Permit
Solar Panel Installation	$19,500 – $62,400	required	Cost·Permit
Kitchen Remodel	$22,800 – $116,700	conditional	Cost·Permit
Bathroom Remodel	$11,500 – $53,600	conditional	Cost·Permit
Driveway Replacement	$5,600 – $25,200	usually required	Cost·Permit
Paver Patio & Walkway	$4,500 – $20,700	conditional	Cost·Permit
Deck Construction	$7,400 – $37,800	required	Cost·Permit
Shed Installation	$2,300 – $15,500	conditional	Cost·Permit
Whole-House Repipe	$6,200 – $22,000	required	Cost·Permit
EV Charger Installation	$1,100 – $5,700	required	Cost·Permit
Hurricane Shutter Installation	$4,500 – $25,200	required	Cost·Permit
Pool Enclosure / Screen Cage	$12,500 – $58,300	required	Cost·Permit
Septic System Replacement	$10,400 – $38,700	required	Cost·Permit
Impact Window Installation	$12,400 – $58,000	required	Cost·Permit
Exterior Door Replacement	$1,200 – $8,900	usually required	Cost·Permit
Garage Door Replacement	$1,900 – $10,400	required	Cost·Permit
Siding Installation	$10,800 – $51,300	usually required	Cost·Permit
Stucco Repair	$1,200 – $20,600	conditional	Cost·Permit
Soffit & Fascia Replacement	$2,400 – $14,900	conditional	Cost·Permit
Gutter Installation	$1,100 – $8,200	rarely required	Cost·Permit
Roof Repair	$600 – $6,600	conditional	Cost·Permit
Flat Roof Replacement	$8,400 – $39,200	required	Cost·Permit
Attic Insulation	$1,500 – $9,200	rarely required	Cost·Permit
Ductwork Replacement	$3,300 – $15,900	required	Cost·Permit
Mini Split Installation	$3,200 – $16,500	required	Cost·Permit
Flooring Installation	$3,100 – $25,100	rarely required	Cost·Permit
Tile Installation	$2,300 – $20,400	rarely required	Cost·Permit
Interior Painting	$2,000 – $12,400	rarely required	Cost·Permit
Exterior Painting	$3,600 – $19,500	rarely required	Cost·Permit
Drywall Repair	$500 – $5,900	rarely required	Cost·Permit
Kitchen Cabinet Refacing	$5,700 – $25,400	rarely required	Cost·Permit
Countertop Replacement	$2,700 – $14,700	rarely required	Cost·Permit
Tub to Shower Conversion	$4,700 – $21,300	usually required	Cost·Permit
Sod Installation	$1,100 – $8,700	rarely required	Cost·Permit
Irrigation System Installation	$2,800 – $12,900	conditional	Cost·Permit
Tree Removal	$600 – $7,400	conditional	Cost·Permit
Outdoor Kitchen	$8,000 – $59,600	usually required	Cost·Permit
Seawall Repair	$11,300 – $134,000	required	Cost·Permit
Dock Construction	$12,700 – $119,900	required	Cost·Permit
Well Installation	$7,600 – $34,500	required	Cost·Permit
Mold Remediation	$2,000 – $20,100	conditional	Cost·Permit
Water Softener Installation	$1,600 – $8,700	usually required	Cost·Permit
Home Addition	$63,000 – $391,700	required	Cost·Permit

Seattle permitting basics

Jurisdiction	Seattle, King County
Building department	Official site
Permit portal	Apply online
Owner-builder permits	Homeowner permits allowed on owner-occupied property
Contractor verification	Verify any license with Washington State Building Code Council before signing

Sources

Sources & verification

Last verified August 2026. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing — they are not quotes. Permit rules change; confirm with the building department before starting work.