Saint Louis ADU Permit Fees & Cost Calculator
City of St. Louis ADU-related fees are not clearly published on a single official ADU fee page in the search results, but the city does publish zoning service fees and appears to use separate building/trade permits with valuation-based building permit pricing for projects over a threshold. No official impact fee or school fee schedule was found in the provided results, so those items should be verified directly with the city and local utilities.
Free ADU fee calculator
Estimate local ADU fees
Step 1 of 5: Location
The calculator uses staged city data from the ADUFee database with visible confidence levels and dated source tracking.
Fee overview
Do not treat the secondary-source permit estimates as exact official fees.
Verify whether the project needs zoning approval, a waiver, or a variance before assuming the listed zoning fees apply.
Confirm current building, electrical, plumbing, and mechanical permit fees directly with the City of St. Louis Building Division.
Confirm whether any utility connection, sewer tap, water tap, or meter fees apply with the relevant local utilities before budgeting.
The relevant jurisdiction is the City of St. Louis, not St. Louis County.
The ADU may trigger only some zoning actions or trade permits, depending on project scope and whether variances/waivers are needed.
FAQs
Are Saint Louis ADU fee estimates official?
No. ADUFee.com provides planning estimates only. Final fees are set by the city, utility providers, school district, and other agencies.
What sources are used for Saint Louis?
The database stores city, state, utility, school, county, and other source links where available. Each estimate should still be verified locally.
Can ADU fees vary within Missouri?
Yes. Permit, utility, school, inspection, and impact fees can vary by jurisdiction, parcel, project size, utility provider, and local interpretation.