Important Note: January 5, 2026, Deadline for Tertius Profiles
Effective January 5, 2026, all agencies must have complete and DOB-approved Tertius profiles to continue working as third-party agencies in the District. Agencies that fail to meet this deadline for approved profiles will be deactivated and cannot perform work until their profile is complete and approved by DOB.
To Participate in the Third-Party Program
Complete your Agency Profile in Tertius.
See the Third-Party Program Procedural Manual and the Tertius User Guide for Third-Party Agencies for details.
What are Special Inspections?
Special inspections require specific expertise to ensure compliance and must be performed by qualified and independent special inspectors approved by DOB.
When are special inspections required?
They are needed for certain projects (e.g., underpinning, structural steel, concrete) involving specialized construction work. (See DCMR 12A DC Construction Code Chapter 17.)
Special inspections are required in addition to regular building inspections because construction involves critical structural safety components, and the quality of construction has a significant impact on a building’s life safety performance.
The DOB Special Inspection Policy Manual explains the procedures and guidelines to be used during design, permitting, and construction.