City of Thornton
Thornton home permits
General info only. Check with a licensed pro and your local building department.
Thornton publishes a one-page list of projects that do and don't need a building permit.
Office: Thornton Building Inspection
| Topic | What the office says | Source |
|---|---|---|
| Outside, permit needed | Attached decks, decks serving the main exit, patio covers, detached structures 200 sq ft+, fences over 7 ft, retaining walls over 48 in, pools/hot tubs, re-roofing over one square, siding/stucco, additions, garages, A/C, solar, panel upgrades, gas lines, window/door replacement. | Official page checked 2026-10-30 |
| Inside, permit needed | Furnace/AC, water heater, boiler, fireplaces, basement finishes, remodeling, electrical/plumbing/structural changes. | Official page checked 2026-10-30 |
| No permit | Painting, flooring, wallpaper, replacing plumbing fixtures, cabinets and countertops, adding insulation; small detached decks and sheds under 200 sq ft; fences 7 ft or less. | Official page checked 2026-10-30 |
| Fee amounts | Unknown Unknown — the official page we checked doesn't say. Ask the office. | Official page checked 2026-10-30 |
| How to apply | Unknown Unknown — the official page we checked doesn't say. Ask the office. | Official page checked 2026-10-30 |
Basic steps
- Check the list
- Apply with the city
- Inspections
Fees
Unknown No fee page confirmed yet.
Inspections
- Unknown
Checked 2026-10-30. Rules change — confirm with the office. See something wrong? Tell us.