Permit basics for backyard buildings

Most cities require a permit once a backyard building crosses a certain size (often 100–200 square feet) or includes plumbing or a permanent electrical circuit. Rules vary a lot by city and county, so treat any number here as a starting point, not a promise.

Call your local building department before you buy a plan, not after. Ask three questions: what triggers a permit at this size and use, what your setback and height limits are, and whether an accessory building needs a separate foundation inspection.

Our plan sets are drawn to make that conversation easy — dimensioned floor plans, elevations and a wall section are usually exactly what a permit desk asks to see. If your jurisdiction wants a stamped engineering review for your specific site (snow load, wind zone, soil), budget time and a small fee for a local engineer to review and stamp the set.

Building without a required permit can complicate insurance claims and home sales later, so it's worth the phone call — it's usually a shorter process than people expect.