Building and Fire Code Scenarios

Note: In order to be considered an accessory dwelling unit, the occupants shall not be provided with an interior access between attached dwelling units.

CODE SCENARIOS

BUILDING CONFIGURATIONS

One Single-Family Residence (SFR) with one detached ADU – two total units

For purposes of building code compliance:

  • these will be reviewed as two one-family dwellings per International Residential Code (IRC)
  • an imaginary property line shall be used for fire separation requirements this will be two single-family building permits

 

 

 

 

SFR

 

ADU

 

 

 

 

 

One SFR with one attached ADU

For purposes of building code compliance:

  • this will be reviewed as a two-family dwelling per IRC
  • this will be one single-family building permit

 

 

 

SFR

ADU

 

 

One SFR with two attached ADUs (townhouse style) – three total units

For purposes of building code compliance:

  • this will be reviewed as townhouses per IRC
  • may need a National Fire Protection Association (NFPA) 13D sprinklers system based on gross floor area
  • Revised Code of Washington (RCW) 64.55 must be satisfied (a condo sale prohibition covenant can do this)
  • this will be one multifamily building permit

 

 

 

 

SFR

ADU

ADU

 

 

 

 

 

One SFR with two attached ADUs(stacked, non-townhouse style) – three total units

For purposes of building code compliance:

  • this will be reviewed as a multifamily apartment per International Building Code (IBC)
  • separate connection to the water main is needed for NFPA 13R sprinklers*
  • RCW 64.55 must be satisfied (a condo sale prohibition covenant can do this)
  • this will be one multifamily permit

 

 

 

 

SFR

ADU

 

 

ADU

 

 

 

One SFR with two detached ADUs (DADUs are not attached to each other)

For purposes of building code compliance:

  • these will be reviewed as three separate one-family dwellings per IRC
  • imaginary property lines shall used for fire separation requirements
  • these will be three single-family building permits

 

 

ADU

 

SFR

 

 

 

 

 

ADU

 

One SFR with two detached ADUs (DADUs are attached to each other)

For purposes of building code compliance:

  • these will be reviewed as a one-family dwelling and a two-family dwelling per IRC
  • an imaginary property line shall used for fire separation requirements
  • these will be two single-family building permits

 

 

 

 

SFR

 

ADU

ADU

 

 

 

 

One SFR with one attached ADU and one detached ADU

For purposes of building code compliance:

  • these will be reviewed as a two-family dwelling and a one-family dwelling per IRC
  • an imaginary property line shall used for fire separation requirements
  • these will be two single-family building permits

 

 

 

 

SFR

ADU

 

ADU

 

 

 

 

*plans shall also include a sprinkler riser diagram, shut-off, and Fire Department Connection (FDC).

Public Works Facts and General Requirements for ADUs

  1. Proposed Accessary Dwelling Unit (ADU) projects must meet all Kirkland Zoning Code (KZC) requirements, specifically KZC Chapter 115.07.
  2. All ADU permit applications (even an interior alteration) must be routed to Public Works for review.
  3. Impact Fees:
    • Transportation impact fees are exempted for ADU in accordance with KMC 27.04.050.
    • Park impact fees are exempted for ADU in accordance with KMC 27.06.050.
    • School impact fees are exempted for ADU in accordance with KMC 27.08.050.
    • Transportation, park, and school impact fees are assessed on the primary single-family residence (SFR) only. An existing SFR, whether remaining or demolished to construct a new SFR, will receive a credit for transportation, park, and school impact fees.
  4. Utility connection charges (i.e. capital facility charges) are assessed in accordance with the latest version of the Public Works Fee Schedule. All fee schedules may be found at the Development Services Fees webpage. 
    • Kirkland Water Capital Facility Charge and Cascade Water Alliance Regional Capital Facility Charge are determined by the meter size associated with a new service. ADUs are not subject to this charge if there are no changes to the water service/meter.
    • ADUs are not subject to Kirkland Sewer Capital Facility charges.
    • The King County Sewer Treatment Capacity Charge Residential form will continue to be used to report connections and reconnections of all dwelling units; the City does not determine the amount of County Capacity Charge that is owed.
    • ADUs are not subject to the Kirkland Surface Water Capital Facility Charge, if the primary residence is already connected to the public storm system.
  5. Required Public Improvements (i.e. half-street or frontage improvements) shall be determined in accordance with KZC 110.For the purposes of determining public improvements, an ADU project is classified as a single-family dwelling addition/alteration. Per KZC 110.70, public improvements are required if the total addition/alteration value exceeds $268,000, based on building construction (alteration) costs in effect on January 1, 2019. This threshold shall be reviewed annually and adjusted by a percentage equal to the percentage of increase in building construction costs.
  6. Access:
    • Only one driveway cut from the public street is allowed for the property / tax parcel.
    • The primary residence must maintain a 20x20 parking pad, unobstructed by site circulation providing access to the development / ADUs (i.e. driveways or drive aisle).
    • Vehicular turnaround(s) must be provided as a part of the site circulation design. Vehicles must be able to back out of garages and parking spots comfortably and to drive forward onto the public street.

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