Union, MO - 2026 Building Permit Guide

Permit Authority

Covers residential, commercial, and industrial work in the city limits; the department coordinates fire district plan review, water/sewer hookups, floodplain permits, and the 2021 I-C code suite listed in the New Home Booklet. 【0†source】citeturn3view0

Department

City of Union Building & Engineering Department. 【0†source】citeturn3view0

Address

10 E. Locust Street, Union, MO 63084. 【0†source】citeturn3view0

Phone

(636) 583-1805. 【0†source】citeturn3view0

Email

buildinginspector@unionmissouri.gov. 【0†source】citeturn3view0

Website

https://www.unionmissouri.gov (the Building Department Document Center hosts the permit application and booklet). 【0†source】citeturn3view0

Online Permit Portal

Application Process

1. Prepare a plot plan/site plan plus two sets of detailed drawings (foundation, floor, wall, stair, elevations, electrical, mechanical, and plumbing information) per the checklist in the New Home Booklet. 【0†source】citeturn3view0
2. Fill out the building permit application with contractor/owner information, estimated construction cost, floodplain status, and water/sewer/meter details. 【0†source】citeturn4view0
3. Submit the plans/application, pay the applicable fees based on the 2021 BOCA schedule, and wait for permit issuance before starting work. 【0†source】citeturn3view0
4. Call (636) 583-1805 with at least 24 hours' notice to schedule inspections; post the permit on-site and ensure subcontractors are listed. 【0†source】citeturn3view0

Typical processing time: Not published; contact the Building Department for an update. 【0†source】citeturn3view0

Source: City of Union Building & Engineering Department. 【0†source】citeturn3view0

General Requirements

All residential, commercial, or industrial projects, structural work, new decks, porches, sheds, garages, carports, swimming pools, and similar improvements must be reported to the Building Department (floodplain permit is also required if the site is in a floodplain). 【0†source】citeturn3view0

Required Documents

• When a permit is required: All residential, commercial, or industrial projects, structural work, new decks, porches, sheds, garages, carports, swimming pools, and similar improvements must be reported to the Building Department (floodplain permit is also required if the site is in a floodplain). 【0†source】citeturn3view0
• Required documents: Plot plan, site plan, two sets of plans covering foundations, floors, walls, stairs, elevations, utilities, mechanical, plumbing, electrical, and any floodplain information; the application also requires the estimated cost and contractor credentials. 【0†source】citeturn3view0
• Permit validity/expiration: Not publicly listed; confirm with the Building Department. 【0†source】citeturn3view0
• Owner-builder rules if available: All permit holders must ensure contractors and subcontractors hold a valid City of Union business license before work begins; the permit is the owner's responsibility. 【0†source】citeturn3view0
• Contractor license requirements: Contractors must have a City of Union business license prior to starting work, as noted in the booklet. 【0†source】citeturn3view0
• Building code adopted: ICC International Building, Residential, Existing Building, Plumbing, Mechanical, Fuel Gas, Property Maintenance, and Energy Conservation Codes (all 2021) plus NEC 2020 and the 2021 Swimming Pool & Spa Code, as noted in the booklet. 【0†source】citeturn3view0

Permit validity

Not publicly listed; confirm with the Building Department. 【0†source】citeturn3view0

Building code

ICC International Building, Residential, Existing Building, Plumbing, Mechanical, Fuel Gas, Property Maintenance, and Energy Conservation Codes (all 2021) plus NEC 2020 and the 2021 Swimming Pool & Spa Code, as noted in the booklet. 【0†source】citeturn3view0

Owner-builder

All permit holders must ensure contractors and subcontractors hold a valid City of Union business license before work begins; the permit is the owner's responsibility. 【0†source】citeturn3view0

Contractor requirements

Contractors must have a City of Union business license prior to starting work, as noted in the booklet. 【0†source】citeturn3view0

Fees

Minimum permit fee

minimum per the listed formula section. 【0†source】citeturn3view0

Plan check fee

Plan review fees are included in the formula (residential requires two sets of prints, commercial requires two sealed sets). 【0†source】citeturn3view0

Permit fee formula

New construction uses square footage x construction cost x multiplier; garage, remodel, and basement permits have their own square-foot formulas (lines 124-137). 【0†source】citeturn3view0

Reinspection fee

reinspection fee for failed inspections, pressure test failures, or missed approvals. 【0†source】citeturn3view0

Payment note

Fees must be paid in full before any inspections occur. 【0†source】citeturn3view0

Fees change. Verify current amounts at the official fee schedule.

Work That Does NOT Require a Permit

Contact the City of Union Building & Engineering Department. 【0†source】citeturn3view0 to confirm whether your project requires a permit before starting work.

Inspections

How to Schedule

• Call (636) 583-1805 with the permit number and inspection type; voicemail messages will be scheduled if no answer. 【0†source】citeturn3view0 ()

Inspection hours

Not published. 【0†source】citeturn3view0

Typical inspection sequence: Setbacks/zoning verification, floodplain check, address assignment, footing and foundation, under-floor plumbing, water/sewer and electrical conduit, rough-in framing/MEP, fireplace, electric service, drywall, and final/occupancy. 【0†source】citeturn3view0

Additional Resources

• Building code: ICC International Building, Residential, Existing Building, Plumbing, Mechanical, Fuel Gas, Property Maintenance, and Energy Conservation Codes (all 2021) plus NEC 2020 and the 2021 Swimming Pool & Spa Code, as noted in the booklet. 【0†source】citeturn3view0
• Zoning information: View zoning info
• License lookup guide: Missouri Contractor License Requirements
• Contract template: Missouri Homeowner-Contractor Agreement
• Missouri hub: Missouri Contractor License & Permit Hub

Frequently Asked Questions

Union Building Permit FAQ

Do I need a building permit in Union, MO?

All residential, commercial, or industrial projects, structural work, new decks, porches, sheds, garages, carports, swimming pools, and similar improvements must be reported to the Building Department (floodplain permit is also required if the site is in a floodplain). 【0†source】citeturn3view0

How much does a building permit cost in Union, MO?

The minimum permit fee is minimum per the listed formula section. 【0†source】citeturn3view0. Fees are calculated as: New construction uses square footage x construction cost x multiplier; garage, remodel, and basement permits have their own square-foot formulas (lines 124-137). 【0†source】citeturn3view0. Plan check fee: Plan review fees are included in the formula (residential requires two sets of prints, commercial requires two sealed sets). 【0†source】citeturn3view0.

How do I apply for a building permit in Union, MO?

1. Prepare a plot plan/site plan plus two sets of detailed drawings (foundation, floor, wall, stair, elevations, electrical, mechanical, and plumbing information) per the checklist in the New Home Booklet. 【0†source】citeturn3view0 2. Fill out the building permit application with contractor/owner information, estimated construction cost, floodplain status, and water/sewer/meter details. 【0†source】citeturn4view0 3. Submit the plans/application, pay the applicable fees based on the 2021 BOCA schedule, and wait for permit issuance before starting work. 【0†source】citeturn3view0 4. Call (636) 583-1805 with at least 24 hours' notice to schedule inspections; post the permit on-site and ensure subcontractors are listed. 【0†source】citeturn3view0

How long does it take to get a building permit in Union, MO?

Typical processing time is Not published; contact the Building Department for an update. 【0†source】citeturn3view0.

What work is exempt from building permits in Union, MO?

The following work is generally exempt: No publicly posted exempt-work list is provided on the New Home Booklet or permit form; coordinate with the Building Department for clarification. 【0†source】citeturn3view0.

How do I schedule a building inspection in Union, MO?

Inspections can be scheduled via: Call (636) 583-1805 with the permit number and inspection type; voicemail messages will be scheduled if no answer. 【0†source】citeturn3view0.