New Building

This application is for construction of new commercial, multifamily and single family residence with or without an Accessory Dwelling Unit (ADU) only. Building systems (mechanical, electrical and plumbing) are separate permits.

The following documentation must be submitted when applying for a new building permit (some information may not be required for your project):

Sewer availability certificate

Water availability certificate

Cross connection control form (Highline Water District)

Septic design plans approved by the King County Health Department if on a septic system

Legal documentation verifying parcel number

Communications Facility Supplemental Application

Accessory Dwelling Unit (ADU) registration form

Soils Report (Unless waived by the Building Official)

Site Plan. Include:

1. Survey, stamped and signed by a licensed surveyor showing:
   • All property lines
   • All buildings
   • Assumed property lines between buildings
   • Adjacent Streets
2. Parking lot layout measurements and calculations, include:
   • Location of light poles
   • Signage
   • On- and off-site fire hydrants
   • Required on-site recyclable storage space
3. Square footage of the entire lot, including all existing and proposed buildings
4. Location of the closest fire hydrants and the driveway

Civil Plans

1. Drainage plan, include all natural drainage courses (see the Residential Drainage checklist)
2. Utility plan (all utilities must be installed underground), include:
   • Water
   • Sewer
   • Electrial
   • Cable
   • Telephone
3. Siltation control plan (unless part of a current SeaTac short plat or subdivision)
4. Soil Amendment Standards (for projects that create 2,000 sq. ft. or more of new impervious surface, or result in 7,000 sq. ft. or more of land disturbing activity), include:
   • Soil amendment calculations
   • Separate site plan indicating projected soil amendment areas
5. T.I.R report. The following must be prepared by a licensed WA State Civil Engineer:

• Civil Engineering Plans
• Erosion & Sedimentation Control Plans
• Storm Drainage

Landscape and Irrigation Plan

Lighting Layout Plan

Architectural Plans (must be stamped and signed by a licensed architect and/or engineer for commercial projects)

1. Provide a complete description of work to be performed. Include a description of the use of the building and rooms, the occupant loads of the spaces, and the allowable areas of the building(s) (Commercial buildings)
2. Floor plans, including:
   • Door locations
   • Window locations
   • Exiting paths
3. Building elevations
4. Exiting paths
5. Stair details
6. Typical wall, ceiling, and floor sections
7. Show compliance with the Sound Transmission Code (if applicable)
8. Washington State Energy Code compliance
9. Show mechanical appliance and plumbing fixture layout on the floor plans

Structural Plans (must be stamped and signed by a WA State Licensed Engineer)

1. Foundation plans
2. Framing plans, include:
   • Roof
   • Wall
   • Floor
3. Lumber specifications, include:
   • Species
   • Grade
   • Spans and spacing
4. Cross/Cut sections
5. Structural notes