Residential building permit in SeaTac, Washington

When you need this permit

• SMC 13.110.020 adopts “The most current edition of the International Residential Code” as amended by the Washington State Building Code Council and published in Chapter 51-51 WAC, “as now or hereafter amended”, together with Appendices F, Q and U. NO EDITION YEAR IS PRINTED ANYWHERE IN THE ADOPTING SECTION.
• THE AMENDED TABLE R301.2 IS THE PART TO READ BEFORE DESIGNING, AND SEATAC'S NUMBERS ARE NOT ITS NEIGHBOURS'. Ground and roof snow load is published as a CONDITIONAL value — “20 psf with drift calculations; 25 psf without drift calculations” — which is the only conditional snow load in this Washington set. Wind speed is 85 mph, seismic design category D2, frost line depth 18 inches, outside design temperatures 24F heating and 83F cooling, mean annual temperature 51.4, and air freezing index 50.
• Flood hazard is given as a community number rather than a date or a map panel: “FEMA # 530320”.
• SMC 13.110 amends R105.2(1) so that detached accessory structures up to 200 square feet are exempt from permit, and the exemption expressly names “tree supported play structures”.
• A local drainage amendment at R405.1.1 requires drains of “a minimum of four inches” and under-floor spaces kept free of running or standing water.
• CHECK WHO YOUR BUILDING OFFICIAL IS BEFORE YOU APPLY — ON PORT OF SEATTLE LAND IT MAY NOT BE THE CITY. SMC 13.100.010(C): “the City recognizes concurrent authority of the Port to administer, implement, and enforce the technical codes and standards adopted in this title and defers to the Port's exercise of such jurisdiction as to development projects on Port-owned property within the City which are for airport uses, as that term is defined in the February 17, 2018, interlocal agreement between the City and the Port.” The agreement is authorised by Resolution No. 17-021. The code does not reproduce the definition of “airport uses”, and that interlocal agreement was not read for this entry, so which projects fall inside the carve-out is NOT ASSERTED HERE.
• SEATAC HAS A SOUND TRANSMISSION CODE THAT MOST WASHINGTON CITIES DO NOT, AND IT CAN BLOCK A CHANGE OF USE. SMC Chapter 13.240 applies to buildings “in the vicinity of Seattle-Tacoma International Airport as identified on the Noise Level Reduction Map” and to sites “included within the Port of Seattle Noise Remedy Program”. The interior standard is “a Day-Night Average Sound Level of 45 decibels or less”, with noise level reduction tiers of 25, 30 and 35 dB at SMC 13.240.100, .110 and .120. It covers dwellings, hotels and motels, offices, schools, churches, theatres and hospitals. THE SHARPEST PROVISION IS ABOUT USE, NOT CONSTRUCTION: a change of use to human occupancy, or to sleeping use, is not permitted unless the building complies. Field testing is done “under the supervision of a professional acoustician” reporting to the Building Official, against ASTM E90, E413, E497, C919 and E336. And “In the case of conflict between this chapter and any other applicable codes, the more restrictive requirements shall apply.”
• PERMIT LIFE, EXTENSION AND RENEWAL, ALL FROM SMC 13.100.060. Expiry (J): a permit for a new building or building addition expires two years from issuance; permits “not necessary to complete a new building or a building addition shall expire one (1) year for the date of issuance” (published wording, quoted as printed). Extension (K), one only: up to twelve months for a new building or addition, six months for mechanical, electrical and plumbing permits, twelve months for right-of-way and clearing and grading permits on subdivisions, each requested BEFORE expiry; plus a 30-day extension purely to take a final inspection and close out, available only if fewer than 180 days have passed since expiry, with one further 30 days if conditions outside the applicant's control are documented. Renewal (L), also once only and for a fee, “provided no changes have been made to the originally approved plans” — one year for a new building or addition if requested within a year of expiry, six months otherwise if requested within six months. A PERMIT THAT HAS BEEN RENEWED CANNOT THEN BE EXTENDED, and “No permit shall be renewed more than once.” Past those windows a new application, a new permit and new fees are required.
• THE APPLICATION HAS ITS OWN CLOCK, SEPARATE FROM THE PERMIT'S. SMC 13.100.060(H): an application for which no permit issues within eighteen months “shall expire by limitation”; separately it expires for inactivity if the applicant “fails to respond to the Department's written request for revisions, corrections, or additional information within ninety (90) days of the date of request”. The 90-day response period can be extended on an approved schedule, but the code is explicit that doing so “shall not extend the time limitation of the application” — the two clocks do not merge. Tolling is available for a cumulative maximum of 180 days: 90 days where a land use approval must come first, or 180 where issuance waits on a related construction permit, or on both. A separate one-time 30-day extension exists only “for the purpose of paying fees, submitting required paperwork, and posting financial sureties”.
• SMC 13.100.100: appeals from the Building Official go to the Hearing Examiner, and “All references in the technical codes to the Board of Appeals shall be deemed to refer to the Hearing Examiner system of Chapter 1.20 SMC.” The section further limits the Examiner's authority over code interpretation; Chapter 1.20 SMC was not opened for this entry, so the procedure and any deadline are not asserted.