Who must seal DC permit drawings? (architect/PE seal + residential exemption)

Short answer. In the District of Columbia, permit drawings that involve the practice of architecture or engineering must be prepared and sealed by a professional registered in DC — a DC-licensed architect or a DC-licensed professional engineer. The one common exception is a nonstructural alteration of an R-3 (one- and two-family) residential building, which is exempt from the seal requirement. The rule sits in the DC Construction Codes (2015 IBC with DC amendments), not in the technical chapters of the IRC or IBC, which is why it is easy to miss.

The rule is layered across three instruments

1. The trigger lives in the administrative provisions of the DC Construction Codes (DC's amendment to IBC Chapter 1, "Professional Services"). It says that where work involves the practice of architecture or engineering, the construction documents must be prepared and sealed by a DC-licensed architect or engineer.
2. The definitions of what counts as the "practice of architecture" and the "practice of engineering" come from the DC Official Code's licensing statutes, which the administrative provision points to.
3. The seal itself — its form and the requirement that each sheet be sealed by the responsible professional — is set by the DC Municipal Regulations governing the architecture and engineering boards.

Which professional seals which sheets

• Architectural drawings → DC-licensed architect.
• Structural, mechanical, plumbing, gas, and electrical drawings → DC-licensed professional engineer (with a narrow exception for the plumbing building-connection, which a master plumber may handle).
• Zoning sheets → no separate professional seal.
• Plats / survey work → the Office of the Surveyor; an interior-only project usually needs none.

The residential exemption, read narrowly

The exemption reaches only a nonstructural alteration of an R-3 residential building. The moment a project adds structural or egress work — for example, a one-unit-to-two-unit conversion that changes the structure or means of egress — it falls outside the exemption and seals are required. It is also worth confirming the actual occupancy classification, because an R-3 two-family dwelling under the residential code and an R-2 stacked building under the IBC are treated very differently.

One frequent misconception

"AIA" is not a license — it is a professional-association membership. The legal requirement is the seal of an architect or engineer registered in the District of Columbia, regardless of any association affiliation.