Mount Vernon is the county seat of Skagit County and sits along the Skagit River floodplain — which means flood zones are a real factor when placing a shed on your property. One-story accessory structures under 200 square feet are permit-exempt, but you still need a location approval from Development Services. The R-1 code also defines a smaller "accessory storage shed" category at 120 square feet that must be in the rear yard, single-story, and can't be taller than your house. No permanent heat source, no sleeping, no habitation. Here's what the Mount Vernon Municipal Code says.
| Shed Permit Rules | City of Mount Vernon |
|---|---|
| Max Shed Size (No Permit) | 200 sq ft (one-story, non-habitable, no plumbing) |
| Accessory Storage Shed (R-1) | 120 sq ft — single story, rear yard only |
| Max Shed Height (Overall) | Cannot exceed height of primary structure (MVMC 17.15.040(G)) |
| Setbacks (Side/Rear) | 5 ft from all property lines and all other structures |
| Setbacks (Front) | Rear yard only — not permitted in front or side yards |
| Alley-Adjacent Garages | 8 ft from rear property line when abutting an alley |
The 200 sq ft exemption requires a location approval from Development Services — it is not fully exempt from city review.
Accessory storage sheds in R-1 zones are limited to 120 sq ft per MVMC 17.15.040(G). Structures above 120 sq ft may require additional review.
“One-story detached accessory structures used as tool and storage sheds, playhouses and similar uses, provided the floor area does not exceed 200 square feet. The building is not used for sleeping purposes. The building is not placed within a defined critical area or its buffer unless critical areas review has been completed and the location has been approved. The building is not located in a designated floodway. The building meets all setback requirements found in the MVMC. A permit approving the location of the structure is obtained from the Development Services Department.”
MVMC 15.04 (IRC R105.2) — Permit Exemption for Accessory Structures →
“An accessory storage shed intended for storage of tools or other household items, provided said shed is limited to 120 square feet, is single story and is not allowed to be taller than the primary structure on the site, has no permanent heat source, is not used for sleeping or habitation, is not located in critical areas or buffers under Chapter 15.40 MVMC, is located in the rear yard and is required to maintain a minimum five-foot setback from all property lines and all other structures.”
MVMC 17.15.040(G) — Accessory Storage Shed (R-1 Zone) →
Have questions about permits or zoning? We don't have all the answers, but we deal with this stuff regularly and can usually help you figure it out. Reach out with your address and we'll point you in the right direction.
Building codes and permit requirements are subject to change. Contact your local building department to verify current regulations before beginning your project.
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