“Do I need a permit for this?” The answer starts in a model code and ends at your local building department. The International Code Council says its International Residential Code (IRC), the code for one- and two-family homes and townhouses up to three stories, is “in use or adopted in 49 states, the District of Columbia, Guam, Puerto Rico and the U.S. Virgin Islands.” Section R105.2 of that code lists the work that needs no permit. States and towns adopt the code with their own changes, and the table below shows how far the permit list can move. Here is the model list, three local versions of it side by side, and a short method for getting the answer for the address on your next estimate.
The rule and its list
The starting point is R105.1: anyone who intends to “construct, enlarge, alter, repair, move, demolish or change the occupancy of a building or structure,” or to install, alter, repair or replace any electrical, gas, mechanical or plumbing system the code regulates, “shall first make application to the building official and obtain the required permit.” Everything that follows is an exception to that sentence. The 2021 edition, as Grant County, Washington reprints it, exempts:
Two things about that list matter more than any single item. First, the exemption is not a pass on the rules: it “shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this code or any other laws or ordinances of this jurisdiction.” A deck that needs no permit still has to be built to code. Second, the list has a companion, R105.2.2 on repairs, in the versions of the 2021 code that Denver and Norwich, Connecticut publish: no application is needed for “ordinary repairs to structures,” but that never includes cutting away a wall, cutting a beam or load-bearing support, changing a required exit, or adding, altering, replacing or moving piping, electric wiring or mechanical work. Everything else falls back on R105.1. A water heater swap, a new circuit and a moved drain are on neither list, and re-roofing is not on the exempt list; the local pages below show how differently towns treat a roof.
Four places, four answers
Here is the same short list as three local building departments publish it, next to the model code. Each is a real department’s own page, read on October 22, 2026.
| Work | 2021 IRC R105.2 | Independence, Missouri | Cincinnati, Ohio | Sonoma County, California (unincorporated) |
|---|---|---|---|---|
| Storage shed | Up to 200 sq ft, one story, detached | Under 120 sq ft | Up to 100 sq ft, 8 ft average height, in the rear yard | Up to 120 sq ft and 12 ft high |
| Fence | Not over 7 ft | Permit only over 6 ft | Fences listed among alterations that need a permit | Solid up to 7 ft; open (lattice, wire mesh) up to 10 ft |
| Deck | Up to 200 sq ft, 30 in or less above grade, freestanding, not serving the required exit | All decks need a permit | Decks listed among alterations that need a permit | 30 in or less above grade, not over a story below, not part of an accessible route |
| Re-roofing | Not on the exempt list | Permit for any re-roof; one layer of roofing allowed | No permit for roof coverings, up to two layers | Not addressed on the page |
| Retaining wall | Up to 4 ft, no surcharge | Not addressed on the page | Separate permit required | Retaining up to 3 ft of material, no surcharge |
Roofs show the spread best. Independence requires a permit for any re-roof. Cincinnati needs none for roof coverings of up to two layers. Horry County, South Carolina, which works from the 2021 IRC, says its permit rule does not apply to “replacing shingles or finished flooring unless structural sheathing is to be replaced.”
Say a fencer quotes a solid 6-foot-6 privacy fence. Under the model code it needs no permit. In Independence it does, because it is over 6 feet. In Cincinnati, fences are on the list of alterations that need one. In unincorporated Sonoma County it needs no building permit, but the county warns that a fence over 6 feet in a rear or side yard setback is “likely to require a use permit.” One fence, four answers, and two kinds of permit.
What skipping a required permit can cost
When the customer offers to pull the permit
A homeowner who offers to get the permit in their own name is offering you a shortcut that some states treat as a warning sign. California’s owner-builder exemption, §7044, covers an owner who does the work personally or with employees paid wages only, or who contracts directly with licensed contractors for each trade, with limits on selling what is built. When an owner signs the owner-builder declaration on a permit application, Health and Safety Code §19825 has them also sign a Notice to Property Owner, which includes this line to initial: “a frequent practice of unlicensed persons is to have the property owner obtain an ‘Owner-Builder’ building permit that erroneously implies that the property owner is providing his or her own labor and material personally.” The owner also initials that they are “the responsible party of record on the permit.”
Massachusetts puts it in the contract. Under General Laws chapter 142A, section 2, a home improvement contract must tell the homeowner of “any and all necessary permits,” that “it shall be the obligation of the contractor to obtain said permits,” and “that homeowners who secure their own permits will be excluded from the guaranty fund provisions of this chapter.”
Getting your own answer in ten minutes
- Find who issues permits at the address. It may be the city, or the county for unincorporated land, as in Sonoma County. The ICC’s code adoption map shows which code editions each state uses; the local department shows its own changes.
- Find its exempt-work page. Cincinnati calls its page “Do I Need A Permit?” and Sonoma County “When Is a Building Permit Not Required?” Note the code edition the page cites; Horry County names the 2021 IRC.
- Not on the list means a permit. Sonoma County says it plainly: “If your project does not appear on this list of exempt work, you should assume that a building permit is required.”
- Check the other approvals. Sonoma lists zoning, setbacks, design review, use permits and drainage. Cincinnati requires separate permits for plumbing, electrical and HVAC work, and a certificate before work on a historic property.
- Write it into the estimate and the contract. Who pulls the permit, its fee, and time for inspections. What a Home Improvement Contract Must Say covers the rest of the contract.
Whether a job that needs a permit also needs a licensed contractor is its own question in some states; Do I Need a Contractor License? walks through it.
General information, not legal or tax advice. Rules change and vary by state; check with the agency named above or a professional for your situation.