Zoning approval vs. building permit — what is the difference?

New homeowners are sometimes surprised to learn that they need to clear two different reviews before they can build an addition: a zoning review and a building permit. The two reviews answer different questions and are usually handled by different offices, even when they sit at the same counter. Zoning review answers the question: are you allowed to build this here at all? It looks at the use of the property, the size and shape of what you propose, and where the proposed structure sits on the lot. Zoning regulations include things like setbacks (how far the structure must sit from each property line), height limits, lot coverage maximums, floor area ratio limits, and use restrictions (whether the lot is zoned for residential, commercial, agricultural, or mixed use). Zoning is concerned with the planning of the community as a whole. Building permit review answers a completely different question: assuming you are allowed to build this here, are you proposing to build it correctly? Building review looks at structural design, fire safety, energy code compliance, electrical, plumbing, and mechanical systems. The reviewer is checking that the construction will be safe and durable. The two reviews interact in important ways. You generally cannot get a building permit until zoning has signed off, because there is no point in reviewing the structural details of an addition that is not legally allowed. Some jurisdictions handle this internally by routing your application through zoning first, then building. Others require you to obtain a zoning verification letter or permit before you can apply for the building permit. If your project does not comply with zoning as written, you have three options. You can redesign the project to comply. You can apply for a variance, which is a request to be excused from a specific zoning rule because of an unusual hardship (this is often the slowest and most uncertain path). Or you can apply for a special use permit or conditional use permit if your use is allowed in your zone with conditions. Understanding which review applies to your question saves an enormous amount of time. Setback questions, height questions, and use questions are zoning questions. Beam-size questions, fire-rating questions, and outlet-spacing questions are building questions. When you call the county, ask for the right office and you will get the right answer faster.