St. Louis City

Home permits and project costs in St. Louis, MO

The city is independent of St. Louis County, so the permitting authority differs on either side of the city line for identical projects.

Model reviewed August 2026

Local cost index

+0%

vs national average

Permit fee index

+2%

vs national baseline

Population

293,310

Homeownership

44%

Do you need a permit in St. Louis?

For most structural work, yes

St. Louis enforces local adoption of the irc; no statewide residential code through St. Louis City. 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 St. Louis

National baselines adjusted by the local labor and materials index.

Project	Typical cost	Permit	Deep pages
Roof Replacement	$9,900 – $33,300	required	Cost·Permit
AC Replacement	$5,300 – $15,900	required	Cost·Permit
Fence Installation	$2,400 – $11,200	usually required	Cost·Permit
Water Heater Replacement	$1,200 – $5,500	required	Cost·Permit
Pool Installation	$39,100 – $118,300	required	Cost·Permit
Window Replacement	$7,800 – $35,200	required	Cost·Permit
Electrical Panel Replacement	$2,000 – $7,000	required	Cost·Permit
Generator Installation	$6,700 – $22,500	required	Cost·Permit
Solar Panel Installation	$15,400 – $49,200	required	Cost·Permit
Kitchen Remodel	$18,100 – $92,700	conditional	Cost·Permit
Bathroom Remodel	$9,100 – $42,300	conditional	Cost·Permit
Driveway Replacement	$4,300 – $19,300	usually required	Cost·Permit
Paver Patio & Walkway	$3,500 – $16,100	conditional	Cost·Permit
Deck Construction	$5,600 – $28,600	required	Cost·Permit
Shed Installation	$1,800 – $12,100	conditional	Cost·Permit
Whole-House Repipe	$4,600 – $16,400	required	Cost·Permit
EV Charger Installation	$800 – $4,300	required	Cost·Permit
Hurricane Shutter Installation	$3,300 – $18,700	required	Cost·Permit
Pool Enclosure / Screen Cage	$9,300 – $43,400	required	Cost·Permit
Septic System Replacement	$7,700 – $28,900	required	Cost·Permit
Impact Window Installation	$9,400 – $43,700	required	Cost·Permit
Exterior Door Replacement	$900 – $6,700	usually required	Cost·Permit
Garage Door Replacement	$1,400 – $7,700	required	Cost·Permit
Siding Installation	$8,200 – $39,000	usually required	Cost·Permit
Stucco Repair	$900 – $16,100	conditional	Cost·Permit
Soffit & Fascia Replacement	$1,800 – $11,300	conditional	Cost·Permit
Gutter Installation	$900 – $6,500	rarely required	Cost·Permit
Roof Repair	$400 – $4,900	conditional	Cost·Permit
Flat Roof Replacement	$6,200 – $29,000	required	Cost·Permit
Attic Insulation	$1,200 – $7,500	rarely required	Cost·Permit
Ductwork Replacement	$2,600 – $12,300	required	Cost·Permit
Mini Split Installation	$2,500 – $12,800	required	Cost·Permit
Flooring Installation	$2,500 – $20,000	rarely required	Cost·Permit
Tile Installation	$1,800 – $16,000	rarely required	Cost·Permit
Interior Painting	$1,500 – $9,500	rarely required	Cost·Permit
Exterior Painting	$2,800 – $15,000	rarely required	Cost·Permit
Drywall Repair	$400 – $4,500	rarely required	Cost·Permit
Kitchen Cabinet Refacing	$4,500 – $20,000	rarely required	Cost·Permit
Countertop Replacement	$2,200 – $12,000	rarely required	Cost·Permit
Tub to Shower Conversion	$3,600 – $16,300	usually required	Cost·Permit
Sod Installation	$900 – $7,000	rarely required	Cost·Permit
Irrigation System Installation	$2,200 – $10,100	conditional	Cost·Permit
Tree Removal	$500 – $5,500	conditional	Cost·Permit
Outdoor Kitchen	$6,100 – $45,700	usually required	Cost·Permit
Seawall Repair	$8,300 – $98,500	required	Cost·Permit
Dock Construction	$9,300 – $88,100	required	Cost·Permit
Well Installation	$5,700 – $25,700	required	Cost·Permit
Mold Remediation	$1,500 – $15,200	conditional	Cost·Permit
Water Softener Installation	$1,200 – $6,600	usually required	Cost·Permit
Home Addition	$46,700 – $290,400	required	Cost·Permit
Heat Pump Replacement	$6,600 – $22,500	required	Cost·Permit
Furnace Replacement	$3,300 – $11,800	required	Cost·Permit
Foundation Repair	$2,800 – $32,500	usually required	Cost·Permit
Basement Waterproofing	$3,000 – $18,100	conditional	Cost·Permit
Drain Field Replacement	$6,100 – $25,600	required	Cost·Permit
Toilet Installation	$300 – $1,100	rarely required	Cost·Permit
Hot Tub Installation	$5,600 – $22,400	usually required	Cost·Permit

St. Louis permitting basics

Jurisdiction	St. Louis, St. Louis City
Building department	Official site
Permit portal	Apply online
Owner-builder permits	Homeowner permits widely allowed
Contractor verification	Verify any license with Missouri Division of Fire Safety before signing

Sources

Sources & verification

Model vintage August 2026. The links above are the issuing agencies' own pages — we publish them so you can confirm the current rule yourself, not as evidence that each fact on this page was re-checked with them today. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing, not quotes. Permit rules change; confirm with the building department before starting work.