Townhouse Requirements

Fire Sprinkler Protection

When there are more than four attached units, sprinkler protection is required per WAC 51-51-0313.

May be required by the Fire Marshal’s Office when access and or water flow are restricted.

Design Professional

Buildings with more than four dwelling units, require an architect per-Washington State Law RCW 18.08

Buildings that do not meet IRC Prescriptive Design Requirements require an engineer per-Washington State Law RCW 18.43

Building Permits

Single-family lots with proposed zero lot line construction require an RES residential building permit for each lot.

Multi-family lots require a CMI commercial building permit for each building (detached group of townhouse units).

Zero Lot Line Construction

Defined as real property lines between units require:

1. Each unit requires an independent one-hour fire-resistant rated wall per R302.2.1
   • a two-hour common wall is not permitted at real property lines
2. Structural independence requires each unit to be designed as a separate building with no other units present.
   • no shielding from wind
3. Eaves or overhangs are not permitted to cross property lines, unless independently supported from the fire wall located on that lot.
4. Utilities are required to be located on the property served and may not cross property lines.
5. Shared gutters and downspouts require a maintenance agreement.

RCW Construction Defect Disputes

When there are more than two attached dwelling units on a multi-family lot, the Revised Code of Washington, RCW 64.55 applies.

Resources

File Naming Standards Plan File Requirements – Leave a blank area on the plans for the Approval Stamp Design Codes and Criteria Washington State Amendments – SBCC Washington State Building Code Council