Do Redmond DADUs Need Fire Sprinklers?
Yes. Redmond’s residential permit page states that new detached ADU units require fire sprinklers. Include the sprinkler system and its water-service implications in the early design and budget.
Sources checked November 5, 2026. Confirm the requirements for your parcel with its permitting authority.
Where does Redmond state the requirement?
The city’s Residential Permits page identifies sprinklers under new residential homes and infill lots and specifically includes detached ADUs. Its application list also links to a fire-sprinkler submittal, and its Fire Permits page supplies the fire application resources.
For the project file, keep the fire application reference beside the residential building application. An equipment or plumbing plan should not quietly assume that a separate fire design has already been included.
Official guidance: Redmond residential building permits, Redmond fire permit applications.
What should be resolved with the water-service plan?
- Who supplies the water-service information for the proposed home?
- Which designer evaluates the fire-system supply requirements?
- What connection, meter or backflow work does the approved approach require?
- Which parts are provider work and which are private construction?
These are coordination questions for the project team, not a prescription for a particular pipe or meter size. Resolve them before the installation is priced as a complete system.
How should a Redmond DADU estimate describe this work?
| Estimate line | Useful scope detail |
|---|---|
| Fire design and approval | Who prepares the documents and handles comments. |
| Sprinkler installation | What system and installation work is included. |
| Service-related work | What water connection or upgrade assumptions are priced. |
| Testing and closeout | Which inspections and documents the contractor supplies. |
Compare estimates using the same assumptions. A low allowance that excludes design or service work should not be compared directly with a complete included scope.
When should you resolve the fire design?
Coordinate it with the building and service drawings before those decisions become difficult to change. Keep the responsible designer, permit status and open questions visible in the project schedule. If the approved solution changes, update the estimate and affected plans together.
TimberworX can discuss a proposed Redmond DADU in a free initial consultation. Detailed design, research and budgeting are paid preconstruction services.
A few things to know
Is a small new cottage automatically exempt?
The city’s published new-detached-ADU statement does not provide a small-cottage exemption. Resolve the project’s requirements with the city.
Can a general plumbing allowance establish the sprinkler scope?
Ask the estimate to identify fire design, installation, service assumptions and closeout separately.
Keep planning
Redmond DADU Permits: What You Need to Know
Redmond DADU permits explained: current zoning, building and utility applications, sprinkler coordination and final approval.
Can a DADU use septic or existing utilities?
Check septic capacity, sewer availability, water service and utility routes before committing to a DADU design in King County.
Eastside DADU Permit Costs: Duvall and Bothell Examples
Compare published DADU permit charges in Duvall and Bothell, Kirkland plan licensing and the separate scope behind a construction estimate.