Quick answer
Most tiny home placements need 4-7 separate permits: building or installation permit, electrical permit, septic permit (rural), foundation permit, ADU permit (when applicable), driveway permit (rural), and certificate of occupancy. Total fees run $150 to $6,500 depending on jurisdiction. Filing should start 30-90 days before delivery. The 4 most common denials are: missing engineering, wrong code citation, incomplete site plan, and missing utility connection plan.
The 7 permits you may need
1. Building or installation permit
The master permit. Required for any dwelling placement in nearly every U.S. jurisdiction. For HUD-code units this is often called an “installation permit”; for modular units it’s a “building permit.” Fee: $200-$2,400. Timeline: 2-12 weeks depending on jurisdiction.
2. Electrical permit
Required to connect to utility or generator power. Often handled by the licensed electrician doing the connection. Fee: $50-$400. Timeline: 1-3 weeks.
3. Septic / sewer permit
Required for any rural placement that uses a private septic system. Includes a percolation test on the soil. Fee: $250-$1,400 plus perc test ($250-$650). Timeline: 4-12 weeks.
4. Foundation permit
Required for permanent foundations (slab, basement, or engineered piers). Often combined with the building permit. Fee: $100-$800. Timeline: 1-3 weeks.
5. ADU permit (when applicable)
If placing as an accessory dwelling unit on existing residential property, this is a separate permit type with specific size, setback, and parking requirements. Fee: $400-$5,000 depending on jurisdiction. Timeline: 30-90 days (states with statutory limits, like California, must decide in 60 days).
6. Driveway / access permit
Required when a new driveway connects to a public road. Fee: $50-$500. Timeline: 2-6 weeks.
7. Certificate of Occupancy
Issued after final inspection confirming the unit meets code and is safe to occupy. Usually no fee beyond the building permit. Required before legal occupancy.
Permit costs by jurisdiction type
| Jurisdiction type | Total permit fees | Total timeline | Notes |
|---|---|---|---|
| Rural unincorporated | $150-$1,400 | 3-8 weeks | Lightest permit load |
| Small town / city | $400-$2,400 | 4-10 weeks | Standard permit set |
| Suburban county | $600-$3,500 | 6-14 weeks | Plus design review |
| Major metro / ADU | $1,800-$6,500 | 8-18 weeks | Full ADU plus impact fees |
| HOA-governed | add $200-$1,500 | add 2-8 weeks | Architectural review on top |
What every permit application needs
Standard documentation set required by most jurisdictions:
- Site plan — scaled drawing showing parcel boundaries, setbacks, utility lines, septic field, driveway, and unit footprint.
- Floor plan — from the manufacturer.
- Manufacturer specifications — HUD label or RVIA cert plus engineering documentation.
- Foundation engineering — pier or slab design, often stamped by a state-licensed engineer.
- Wind / snow / seismic compliance proof — varies by jurisdiction.
- Utility connection plan — how water, sewer/septic, electric, and gas (if any) will connect.
- Septic perc test results — if private septic.
- Insurance proof of liability coverage — some jurisdictions require this with the application.
The 4 most common reasons permits get denied
1. Missing engineering documentation
Foundation engineering or wind-load engineering missing or unstamped. Resolution: hire a state-licensed structural engineer ($600-$2,400) to review and stamp.
2. Wrong code citation
Application cites the wrong code (e.g., IRC for an HUD unit, or HUD for a modular unit). Resolution: verify the unit’s certification and re-submit with correct code reference.
3. Incomplete site plan
Setbacks not labeled, septic field not shown, driveway connection missing. Resolution: redraw to scale with all required elements; many jurisdictions require a licensed surveyor for sites over a certain complexity.
4. Missing utility connection plan
Electric service tap, septic discharge, water source not documented. Resolution: get letters from utility providers confirming connection feasibility, attach to resubmission.
Information gain: the permit timing trick that saves 6 weeks
Most buyers file permits after they sign the unit purchase contract. The professional approach is to file the permit application before you take delivery, even before you sign the deposit. Specifically: get all the documentation in hand (manufacturer specs, foundation engineering, site plan), then file the building permit while the unit is still in factory production.
The math: factory build takes 4-8 weeks; permits take 4-10 weeks. If you file at deposit, the permit is approved before or shortly after the unit ships. If you file at delivery, the unit sits while the permit processes — and you may pay storage fees of $200-$600/month plus delayed-occupancy hassle.
Permit help
Our team can pre-pull the permit application checklist for your specific county before delivery. Send your parcel address to /contact-tiny-homes/ and we’ll return the full permit list, expected fees, and the documents you’ll need to submit. For zoning verification first, see our county zoning verification guide.
