Building a Shed in Whatcom County? Here's What You Need to Know

Whatcom County exempts sheds under 200 square feet from building permits — but the conditions are specific. Your shed must be one-story with no basement, non-occupied, and maintain 10 feet of separation between exterior walls and 6 feet between eaves of adjacent buildings. That separation rule is stricter than most counties and catches people off guard. Setbacks depend on your zoning district (urban residential, rural residential, and rural all have different requirements), and critical areas like wetlands, shorelines, and steep slopes add another layer of regulation. Whether you're near Bellingham or out in the Nooksack Valley, here's what the county code says.

Whatcom County Building Codes & Permits

For unincorporated Whatcom County areas. Incorporated cities may have their own requirements.

Shed Permit RulesUnincorporated Whatcom County
Max Shed Size (No Permit)200 sq ft
Max Shed Height (Overall)Per zoning district* — typically 25–35 ft
Setbacks (Side/Rear)Per zoning districtcheck your parcel
Setbacks (Front)Per zoning district — check your parcel
Min. Separation (Exterior Walls)10 ft
Min. Separation (Eaves)6 ft

*Whatcom County does not publish a separate height limit for accessory structures — zoning district heights apply (UR: 35 ft, RR: 35 ft, RR-I: 25–30 ft). For permit-exempt one-story structures, IRC defaults apply: 10 ft eave height.

From the Municipal Code

1-story detached, non-occupied accessory structures without basements, used as tool and storage sheds, playhouses, and similar uses are exempt from permits provided that accessory structures maintain a minimum separation of 10 feet between exterior walls and a minimum separation of 6 feet between eaves of adjacent buildings on the same property, meet all applicable setback requirements, and floor area does not exceed 200 square feet measured outside wall to outside wall.

WCC 15.04 — Permit Exemption for Accessory Structures

The placement of the building must meet all code requirements related to any critical areas on the parcel, proximity to a septic system or well.

WCC 15.04 — Critical Area and Septic Requirements

All structures, including accessory structures, shall be placed on their lots in compliance with the requirements of the setback table.

WCC 20.80.200 — Setback Compliance for All Structures

What You Need to Know

  • Setbacks (WCC 20.80.200): All structures including accessory buildings must comply with the setback table for your specific zoning district. Urban residential, rural residential, and rural zones all have different requirements — always check your parcel.
  • Building Separation: Whatcom County requires 10 feet between exterior walls and 6 feet between eaves of adjacent buildings on the same property. This is stricter than most counties and can affect shed placement on smaller lots.
  • Critical Areas: The exemption only covers building permits — all fire, natural resources, zoning, and setback requirements still apply. Placement must meet all code requirements for critical areas on the parcel, proximity to a septic system or well.
  • Utilities: Even if the shed is exempt from a building permit, any electrical, plumbing, or mechanical work requires a separate trade permit.
  • Easements: You cannot build on a recorded easement (utility, drainage, etc.) regardless of whether you need a permit or not.

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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