How Bethlehem Handles Accessory Structures: A Practical Guide

Bethlehem maintains 100 local ordinances across all categories, and 5 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where Bethlehem falls on the strict-to-permissive spectrum compared to other cities.

ADU Rules

Bethlehem is a Pennsylvania city of approximately 75,781 residents that straddles Lehigh County and Northampton County in the Lehigh Valley. The City of Bethlehem Code is hosted on American Legal Publishing at https://codelibrary.amlegal.com/codes/bethlehem/, and the Bethlehem Zoning Ordinance is maintained as a separate comprehensive document that the City rewrote in a multi-year process completed around 2023. Pennsylvania has not enacted any statewide accessory dwelling unit (ADU) preemption statute comparable to California Government Code §66313 et seq. or Oregon ORS 197.312, so whether an ADU (sometimes called an accessory apartment, in-law suite, or second dwelling unit) is permitted on a Bethlehem property is determined entirely by the Bethlehem Zoning Ordinance under the Pennsylvania Municipalities Planning Code (53 P.S. §10101 et seq.). Property owners should request a written zoning determination from the Bethlehem Department of Community and Economic Development before making design or financing commitments.

Key details: State ADU Preemption: None (locally controlled). Local Authority: Bethlehem Zoning Ordinance. Enabling Statute: PA MPC 53 P.S. §10101+. Building Code: PA UCC (34 Pa Code 401+). Review Body: Bethlehem Zoning Hearing Board.

Building or occupying an unpermitted ADU in Bethlehem is a zoning violation enforceable under 53 P.S. §10617 (notice of violation, cease-and-desist) and §10617.2, which authorizes civil penalties up to $500 per day per violation, with each day of continuing violation treated as a separate offense. Unpermitted construction also violates the Pennsylvania UCC at 34 Pa Code §401.7 and can result in stop-work orders issued by the Bethlehem Building Code Official under PA UCC §403.65. Bethlehem Code Enforcement may seek injunctive relief in the Court of Common Pleas of Lehigh County or Northampton County depending on the parcel's location.

Shed Rules

Sheds and similar accessory structures in Bethlehem are regulated by two overlapping layers: (1) the Bethlehem Zoning Ordinance, which sets dimensional standards (maximum size, height, setbacks, lot coverage, and location relative to the principal dwelling) by zoning district; and (2) the Pennsylvania Uniform Construction Code at 34 Pa Code §403.1, which exempts certain non-residential utility sheds under 1,000 square feet from UCC building-permit requirements but does not exempt them from local zoning compliance. Bethlehem property owners typically still need a zoning permit from the Bethlehem Department of Community and Economic Development even when no UCC building permit is required, especially in older row-house neighborhoods of Historic Bethlehem and South Bethlehem where rear-yard space is constrained.

Key details: UCC Permit Exemption: Generally <1,000 sq ft (34 Pa Code 403.1). Zoning Permit: Still required for most sheds. Typical Location: Rear yard, behind front building line. Setbacks: Set by district (commonly 3-5 ft). Civil Penalty: Up to $500/day (53 P.S. §10617.2).

Installing a shed without a required zoning permit is a violation of the Bethlehem Zoning Ordinance enforceable under 53 P.S. §10617 (notice of violation, cease-and-desist) and §10617.2 (civil penalty up to $500 per day per violation). Unpermitted sheds in setbacks or exceeding lot coverage may be ordered removed. Sheds over the UCC threshold built without a building permit additionally violate 34 Pa Code §401.7 and trigger stop-work orders from the Bethlehem Building Code Official under PA UCC §403.65.

Garage Conversions

Converting a Bethlehem garage into habitable space (a bedroom, in-law suite, home office, or accessory dwelling unit) requires both (1) zoning approval under the Bethlehem Zoning Ordinance for the change of use — because the converted space is no longer accessory parking and may count toward floor area or trigger an ADU classification — and (2) a building permit under the Pennsylvania Uniform Construction Code at 34 Pa Code §401.7. Conversions must comply with the 2018 International Residential Code for habitable spaces (egress windows under IRC R310, ceiling height under IRC R305, light and ventilation under IRC R303, smoke alarms under IRC R314, carbon monoxide alarms under IRC R315), and Bethlehem's local off-street parking minimums must still be met after the garage is repurposed.

Key details: PA Building Code: PA UCC (2018 IRC/IBC adopted). Egress Standard: IRC R310 (5.7 sq ft minimum). Ceiling Height: IRC R305 (7 ft habitable rooms). Smoke/CO Alarms: IRC R314/R315. Zoning Review: Change-of-use approval required.

Performing a garage conversion without permits violates 34 Pa Code §401.7 (PA UCC) and the Bethlehem Zoning Ordinance. Enforcement includes stop-work orders under PA UCC §403.65, requirements to undo the conversion or obtain after-the-fact permits with elevated fees, and civil penalties up to $500 per day under 53 P.S. §10617.2 for the zoning violation. Unpermitted habitable conversions that fail to meet IRC R310 egress are frequently cited in fire-injury cases and can expose the owner to civil liability. Properties whose parking falls below the zoning minimum may also be cited.

ADU Permits

An accessory dwelling unit in Bethlehem requires permits from two municipal offices: a zoning permit from the Bethlehem Department of Community and Economic Development (confirming the ADU is permitted in the underlying district under the Bethlehem Zoning Ordinance, either by right or by special exception/variance through the Bethlehem Zoning Hearing Board), and a building permit from the Bethlehem Building Code Official under the Pennsylvania Uniform Construction Code at 34 Pa Code §401.7 for the construction itself. Pennsylvania has no statewide ADU preemption like California's SB 9 or Oregon's HB 2001, so timelines, fees, and approval criteria are set by the Bethlehem Zoning Ordinance and the PA UCC.

Key details: Permit Tracks: Zoning + Building (both required). Building Permit Authority: PA UCC 34 Pa Code §401.7. Hearing Board Notice: 10-day published (53 P.S. §10908). Variance Standard: Five-prong hardship (53 P.S. §10910.2). Inspections: Footing, framing, rough-in, final.

Constructing an ADU without permits violates 34 Pa Code §401.7 (building) and the Bethlehem Zoning Ordinance (zoning). Enforcement under 53 P.S. §10617 (notice of violation) and §10617.2 (civil penalty up to $500 per day) by Bethlehem Code Enforcement. Stop-work orders may be issued by the Building Code Official under PA UCC §403.65. After-the-fact permits typically carry doubled fees and require the applicant to demonstrate code compliance through invasive inspections. Occupancy without a Certificate of Occupancy is also a violation.

ADU Impact Fees

Pennsylvania municipalities have unusually limited statutory authority to impose impact fees on new development. Under the Municipalities Planning Code Article V-A (53 P.S. §§10502-A through 10503-A), the only authorized impact fee is a transportation impact fee, and even that requires a multi-year traffic study, an adopted ordinance, and defined impact-fee districts. Other typical "impact" charges (water/sewer connection fees, school district contributions, recreation fees) operate under separate statutory authorities. ADU applicants in Bethlehem generally face only standard zoning and building permit fees, water/sewer tap-in charges through the Bethlehem Authority and the City of Bethlehem sewer service, and any small recreation fee-in-lieu if applicable — no school impact fee and (unless Bethlehem has adopted one under Article V-A) no transportation impact fee.

Key details: PA Impact Fee Authority: Transportation only (Act 209 of 1990). Water/Sewer Tap-In: Authority Act (53 Pa.C.S. §5601+). School Impact Fees: Not authorized in PA. Recreation Fee-in-Lieu: Per 53 P.S. §10503(11), subdivisions. Typical ADU Charges: Permits + tap-in only.

Failure to pay required permit and tap-in fees prevents permit issuance and the issuance of a Certificate of Occupancy under PA UCC §110. Pennsylvania municipalities that attempt to collect impact fees outside the 53 P.S. §10502-A framework face challenge under the Home Builders Association of Metropolitan Pittsburgh v. West Deer Township line of cases interpreting MPC limits on municipal exactions. Fees collected without statutory authority are subject to refund. School district attempts to impose impact fees have been rejected as ultra vires.

The rules around adu impact fees in Bethlehem lean permissive, but that does not mean anything goes.

The Bottom Line

Bethlehem's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Bethlehem is broadly strict or permissive.

These rules come from Bethlehem's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.