Redmond DADU Permits: What You Need to Know
A Redmond DADU needs residential permit review, and the city explicitly requires sprinklers for new detached ADUs. Use current RZC 21.04.1110 for ADU zoning and coordinate the building, fire and utility applications.
Sources checked November 5, 2026. Confirm the requirements for your parcel with its permitting authority.
Which Redmond zoning section applies?
The current ADU and tiny-home section is RZC 21.04.1110, recently amended by Ordinance 3261. Older search results can point to the former 21.08.220 section or proposed amendment documents. Start from the live codified section rather than treating an old marked-up PDF as the adopted rule.
| Current section topic | Published starting point |
|---|---|
| Number | Two ADUs or tiny homes per residential lot. |
| Ordinary ADU size cap | 1,000 sq ft, with specified increase provisions. |
| Detached-unit siting | Underlying lot-coverage and other residential standards apply; the section has a public-alley/right-of-way provision. |
Official guidance: Redmond RZC 21.04.1110: ADUs and tiny homes.
What belongs in the application plan?
Redmond’s residential guidance lists building, electrical, fire-sprinkler, mechanical, plumbing and utility applications as separate potential submittals. Identify the applicable set for the cottage and its site work rather than assuming every approval is bundled into one building application.
- Establish the parcel zone and proposed footprint.
- Prepare the building and required site documents.
- Coordinate sprinkler, water and sewer information.
- Submit the applicable applications and respond to the assigned review comments.
Use one revision record for the set. If a water-service or footprint decision changes, identify the other drawings affected before resubmitting.
Official guidance: Redmond residential building permits.
What makes Redmond’s sprinkler requirement important?
The city’s new-residential guidance specifically includes detached ADUs in its sprinkler requirement. Account for that work while the water service and building systems are being planned. The dedicated guide below explains the questions to resolve.
Separate the sprinkler design and installation scope from a basic plumbing allowance. The estimate should say who prepares the fire documents and what service work the price assumes.
Official guidance: Redmond residential building permits.
What happens after permit issuance?
Plan the inspections and final approvals as part of the schedule. Keep issued drawings and approved revisions aligned with the work in the field. Resolve corrections through the city’s process before considering the project ready for occupancy.
TimberworX offers a free Redmond DADU consultation. Detailed design and budgeting are paid preconstruction services. Bring the property records, intended use and any service information so the team can identify the next design decisions.
A few things to know
Is the old Redmond ADU section the right starting point?
Use the live current code and confirm later ordinances with the city.
Are sprinklers part of planning a new Redmond DADU?
Yes. The city’s residential guidance expressly includes new detached ADUs.
Keep planning
Do Redmond DADUs Need Fire Sprinklers?
Yes, Redmond requires sprinklers for new detached ADUs. Understand the fire application, water-service coordination and estimating questions.
What permits do you need for a DADU?
A practical DADU permit checklist covering site plans, building review, utilities, trade permits and final inspections.
Do you need a survey for a DADU?
Understand how a DADU site plan differs from a survey and which property information supports design and permit review.