Bethlehem, PA Accessory Structures: ADU Permits (2026)

The two-track permitting process for a Bethlehem ADU works as follows. Zoning Track: The applicant first verifies that an ADU is permitted in the underlying district under the Bethlehem Zoning Ordinance (rewritten ~2023). If permitted by right (an "as of right" use), a zoning permit is issued by the Department of Community and Economic Development upon a showing of compliance with dimensional standards. If permitted only by special exception or conditional use, the application goes to the Bethlehem Zoning Hearing Board under 53 P.S. §§10901-10916, which holds a public hearing with notice under §10908 (10-day published notice and posted notice on the property). If a variance is needed, the applicant must satisfy the five-prong hardship test of 53 P.S. §10910.2: unique physical conditions of the property, no possibility of reasonable use without variance, hardship not created by the appellant, no adverse effect on public health and safety, and minimum variance affording relief. Building Track: After zoning approval, the applicant submits stamped construction documents (typically by a PA-licensed architect for new dwelling units above a threshold) to the Bethlehem Building Code Official under PA UCC 34 Pa Code §403.42a. Plan review confirms 2018 IRC compliance for one- and two-family dwellings (or IBC for townhouses or three-family-plus configurations). Inspections occur at footing, foundation, framing, rough-in, insulation, and final stages. A Certificate of Occupancy is issued under §110 of the IRC/IBC before the ADU may be lawfully occupied.