The purpose of DPD’s Special Inspection Program is to monitor and test materials and workmanship of structural systems that are critical to the integrity of the building structure.
Special Inspections, along with Structural Observations, are in addition to the inspections performed by Seattle Building Inspectors.
These inspections are required by and detailed in Chapter 17 of The Seattle Building Code and are required for the following types of work:
- Structural Steel & Aluminum
- Reinforced Concrete
- Reinforced Masonry
- Structural Wood
- Fire Resistant materials and coatings
- Seismic Resistance Systems
- Pile & Pier Foundations
- Soils
- Environmental Assets
The DPD approved set of plans will list the types of required Special Inspections or Structural Observation required for your project.
Special Inspections are not required for:
- Minor work when approved by DPD
- Construction not required to be designed by a registered design professional
The project’s owner or the owner’s agent is responsible for selecting and employing Special Inspection Agencies or Structural Observers.
- Structural Special Inspection Agencies are qualified inspection professionals such as agencies listed on the Washington Association of Building Officials (WABO) website, engineering firms, and other governmental agencies.
- Geotechnical Special Inspection Agencies must be the Geotechnical Engineer of Record for the project and be licensed as a Professional Engineer in the State of Washington.
- Environmental Special Inspection agencies are qualified environmental design professionals such as Landscape Designers, Wetland Biologists, Arborists, and Fisheries Biologists.
- Structural Observers must be a licensed design professional in the State of Washington.
Each project needing Special Inspection is required to hold a preconstruction meeting at the site with DPD. No other inspections can be scheduled with DPD until this preconstruction conference is held. Once you (or your contractor) have requested this meeting by calling (206) 684-8860, a DPD inspector will return the call, set the agenda, determine the attendees, and schedule a meeting.

