Washington, DC Permit Requirements: Deck & Patio Permits (2026)

Washington DC's Department of Buildings (DOB) requires deck permits for deck construction on single-family and two-family dwellings. DOB publishes a specific Deck Guide with current construction code requirements. Decks must comply with structural requirements including footings, framing, ledger connections, and guardrails. Guardrails are required on decks more than 30 inches above grade. Under DC zoning, structures that are not actual buildings and are 4 feet or less above grade can be located in required yards, meaning low decks and patios may have more flexibility in placement. Patios at ground level (concrete, pavers, flagstone at grade) that are flat on the ground are not considered structures and generally do not require building permits. Front patios or any work in the area between the property line and the curb require a DDOT Public Space Permit. Decks count toward lot coverage calculations. In historic districts, visible deck construction may require HPO review. DOB handles permit applications through its online portal.