Tertius

Expanded. Enhanced. All-in-one shop
for construction inspections in the
District.

Providing access to certified third-party
agencies, DOB Construction Inspectors,
and DOEE environmental inspections.
  • One Platform
  • Centralized Inspection Management
  • Certified Inspectors
  • Flexible & Transparent Scheduling
  • 4+

    Disciplines and growing Third-party, special inspections, DOB in-house, DOEE
  • 7,975

    New projects in fiscal year 2025
  • 100%

    Qualified and certified inspectors
  • 16,000+

    Combined inspections in fiscal year 2025

Our growth story

Since its 2021 launch for third-party inspection, Tertius has expanded to include DOB construction inspections, integrated DOEE services, and introduced a full-discipline certification - giving customers more visibility, flexibility, and control than ever before.

Looking for an inspector?

Permits can be inspected either by third-party or by DOB Inspectors

Third-party construction Inspections

Inspection fees are set by third-party companies and paid through Tertius
  • Regulatory Code, Special Inspections and DOEE Inspections
  • Only DOB and DOEE approved agencies
  • Track inspections, download reports, and pay for inspection services with one login

Log in to TPIA

DOB construction Inspections Scheduling

The cost of the inspection is already included in the permit fees
  • Free service
  • Schedule within the next 2 weeks
  • DOB inspecors are certified and approved

Log in to DOB

How it works

A transparent system that ensures every inspection is submitted and received by the appropriate District authority.
  1. 1

    Select the discipline

    Third-party Regulatory Code, Special Inspections, DOEE erosion and sediment control inspections.

  2. 2

    Create a Tertius project

    Create a project with the inspection agency you select by using the address or permits.

  3. 3

    Coordinate inspection scheduling

    Review reports, and manage the inspections services. 

  4. 4

    Pay through Tertius

    Conveniently pay for the inspection services through Tertius.

  5. 5

    Monitor inspection progress

    See when permits are completed. This finalizes your project. 

Need more information?

Contact Us