Redmond ADU Zoning Rules & Permit Guide

ADU Regulations in Redmond, Washington

Updated September 29, 2026

Home to Microsoft's headquarters in King County, Redmond permits ADUs under Washington's HB 1337. The city's Link Light Rail extension has created transit zones where parking requirements are waived for ADU projects.

Below is a summary of the key zoning rules applicable to Accessory Dwelling Units in Redmond as of 2026. Regulations are governed by Washington's HB 1337 (2023) which limits local ADU restrictions statewide.

Additional Local Requirements for Redmond

• ADU by right in residential zones
• Minimum 200 sq ft
• Tree retention standards may apply
• Light rail proximity waives parking (HB 1337)

Frequently Asked Questions About ADUs in Redmond

Can I build an ADU in Redmond?

Redmond permits ADUs under Washington's HB 1337. Parking is not required near the Redmond Technology transit station.

What is the maximum ADU size allowed in Redmond?

ADUs in Redmond can be up to 1,000 square feet, subject to the property's zoning and lot coverage limits. Always confirm the exact allowed size with the Redmond planning department before designing your project.

What are the setback requirements for an ADU in Redmond?

ADUs in Redmond generally require setbacks of 5 ft rear, 5 ft side. Washington's HB 1337 (2023) limits how restrictive local ADU rules can be, but the exact setback figures come from Redmond's own land use code — confirm them with the city before you design.