Accessory Dwelling Units

Fircrest is proud to be a city that can offer ADUs as an alternative to standard Single-Family living. There are two general types of ADUs — Attached and Detached.

Attached ADUs
Attached ADUs are located within or attached to the primary residence. An Attached ADU could be created entirely within the existing walls of your house (for example, as a basement or attic conversion). An Attached ADU could also involve an addition to the house (such as adding a story or extending the house into the rear/side yard).

Detached ADUs
Detached ADUs are separate structures located in the rear / side yard of the main dwelling. Detached ADUs could be constructed as a completely new structure. Or the ADU could be a conversion and/or addition to an existing accessory structure (such as adding a second story to or converting a garage).

There are different permitting standards that apply to Detached ADUs than Attached ADUs.  These standards affect the building, land use, utility regulations, scope of work, and budget. See below for more information.

How Do I Apply?

All applications and required documentation, regardless of ADU type, must be submitted to

Attached ADU Submittal Checklist
  • Submit the ADU application and the required fee of $150.00
  • One complete building permit application
  • Two sets of floor plans – Floor plan requirements
  • Two sets of Site Sketch/Site Plan
  • Contact TPU for a separate electrical meter install
  • After the final building inspection, file the Concomitant agreement with Pierce County, Assessor-Treasurer at applicant’s expense before building final. Return recorded document to the City of Fircrest for filing and retention.

Attached ADUs may be approved by the Director subject to administrative design review in accordance with FMC 22.66, provided the standards and criteria in subsection (c) are met by the proposal: FMC 22.58.012

Detached ADU Submittal Checklist
  • Submit Detached ADU application and required fee of $1,400.00
  • One complete Accessory building permit application
  • Two sets of construction plans
  • Two sets of Site Sketch/Site Plan
  • Contact TPU for a separate electrical meter install
  • After the final building inspection, file the Concomitant agreement with Pierce County, Assessor-Treasurer at applicant’s expense before building final. Return recorded document to the City of Fircrest for filing and retention.

A Detached ADU shall be processed as a conditional use, pursuant to Chapter 22.68 FMC. Detached ADUs cannot be solely approved by the staff. They require a public process with notification to the neighbors. A Public Hearing is held by the Hearing Examiner.

  • Before any conditional use permit may be granted, the Hearing Examiner shall adopt written findings showing that the following criteria are met by the proposal: FMC 22.68.003
Code Requirements
  • The ADU must satisfy the requirements of all construction codes adopted by the city (FMC Title 12.04) Including building, electrical, fire, mechanical, and plumbing code requirements.
  • Fircrest Municipal Code requires all ADU’s to be owner-occupied. Please follow link to FMC 22.58.012 for all Code Requirements related to owner-occupant regulations.
  • The ADU will be subject to land-use standards that are listed here in FMC 22.58.003.
  • For zoning questions, the zoning map can be found here. Once you determine what zone you are located in, you can visit FMC Title 22 to read about the zoning requirements of your parcel.
Other FAQs
Does TPU require a separate Electrical Meter for my ADU?

Yes! Please follow the link to apply for new electrical services. The standard “new service fee” is $50. Electrical Engineer site visits are currently 4-6 weeks out. TPU also requires an electrical permit for an additional fee once the site visit has been completed. Please follow the link to apply for electrical permit.

Are Building Permits Required?

Yes! All building permit applications must be submitted at the time of ADU submittal.

Any work that is being done to the existing building, plumbing system, or mechanical system will require a permit from the city. This includes but is not limited to: new or altered construction of walls, stairs, guardrails, drywall; new or altered plumbing lines, added plumbing fixtures, and new or altered mechanical work, ducting, or appliances. Any newly hated space will also have to comply with the Washington State Energy Code. All permit applications can be found here.

Will my ADU connect to the main house water, sewer, storm drain?

Yes! The City of Fircrest requires all ADUs to connect to the main house utilities. TPU has different requirements for power.  Please see above.

Will my ADU get a separate address?

Yes. An attached ADU will receive the same address as the principal structure but will be assigned a “Unit B” address. For example, If the main house’s address is 4600 Maple Street, the attached ADU would be addressed as 4600 Maple Street Unit-B.

For detached ADUs, using the above address example, the detached ADU would be addressed as 4602 Maple Street and the main house would remain 4600 Maple Street. There may be variations to the detached ADU address depending on if the lot is a corner lot or what the neighbors address is.

Every parcel obtaining a permit for ADU and DADU will also have a primary dwelling that is addressed. Fircrest’s goal in addressing an ADU or DADU is to identify separate living spaces and access points for dwellings other than the primary. This allows emergency response services to locate and enter a dwelling as quickly as possible in the event of an emergency.

For address requests regarding existing dwelling units, tenant spaces, or structures, the legitimacy of the unit, tenant space, or structure must be verified/confirmed that it had been constructed with the proper permits. Regardless of the type of address needed, it can only be assigned to the dwelling unit, building, tenant space, etc. when it has been authorized through the permit process.

The City will forward the new ADU address to relevant stakeholder agencies to alert them of the change, including: USPS, South Sound 911, and Pierce County GIS.

How long with the Public Hearing Process take for a detached ADU? And what is public notice?

The Public Hearing/ Public Notice process is a mechanism to allow the neighbors to be informed of a decision that may impact them. We inform neighbors of the Public Hearing date and time. The Public Hearing process takes roughly 2-3 months. The Public Hearing is heard in front of the Hearing Examiner.

How big can my detached ADU be?

Detached ADU’s can be 600 square feet without any extra permitting. If you choose to exceed 600 square feet, the maximum size is 800 square feet. In order to build an ADU bigger than 600 square feet, an Administrative Use Permit will need to be applied for in addition to the Conditional Use permit.

What about a separate driveway?

The City only allows one driveway. See FMC 22.60.008.

How do I set up trash service for my ADU?

First, please contact the Pierce County Assessor to add the new ADU address to the Assessor’s website. You may contact them here:

Contact Information
Ph: (253) 798-6111
Fx: (253) 798-3142
Contact Us

Hours of Operation
Monday – Friday
8:30 a.m. – 4:30 p.m.

2401 S. 35th St.
Room 142
Tacoma, WA 98409

Next, please set up an online account with Westside Disposal at:

Please contact Westside Disposal with any questions.

Westside Disposal
2815 Rochester St W
University Place, WA 98466
(253) 564-3212
8:30-4:30 Monday-Friday
Yard Waste Dropoff 8:30-4:00 Monday-Friday