Do I need a permit for accessory dwelling unit (adu) in Chatham Borough?
Yes. In New Jersey, accessory dwelling unit (adu) generally requires a permit, and Chatham Borough is no exception.
A new dwelling unit, detached or inside the house, requires a construction permit (N.J.A.C. 5:23-2.14(a)), and all state, county, and local prior approvals, including zoning, must be given before a permit issues (N.J.A.C. 5:23-2.15(a)5). New Jersey deleted IRC Appendix BC, Accessory Dwelling Units, from its one- and two-family dwelling subcode (N.J.A.C. 5:23-3.21(c)25iv); whether an ADU is allowed is a municipal zoning question. When work creates an additional dwelling unit inside an existing home, the new unit must be separated by fire partitions or floor assemblies with at least a one-hour fire resistance rating (N.J.A.C. 5:23-6.6(e)). A contractor building a new one- or two-family dwelling must show a state builder registration under the New Home Warranty and Builders' Registration Act, or an owner who builds it files an affidavit (N.J.A.C. 5:23-2.15(b)1i).
Documents you may need
- Municipal zoning approval for the additional unitRequired
- Construction permit application with all subcode sectionsRequired
- Site plan from a boundary survey with setbacks and utilitiesRequired
- Sealed plans, or an owner affidavit for owner-prepared plans where allowedRequired
- Energy compliance documentationRequired
Possible inspections
- Footing and foundation inspection
- Framing and electrical, plumbing, and mechanical rough-in inspections
- Insulation inspection
- Final inspection and certificate of occupancy
Frequently asked questions
- Do I need a permit for accessory dwelling unit (adu) in Chatham Borough?
- Yes. In New Jersey, accessory dwelling unit (adu) generally requires a permit, and Chatham Borough is no exception. The documents and inspections sections on this page list what the building department typically asks for.
- Who issues the permit in Chatham Borough?
- The local building department for Chatham Borough handles permitting. This page lists its contact details and online portal. Your mailing city is not always the permitting authority, so confirm the jurisdiction before you apply.
- How do I find out the exact requirements for my project?
- Run the free PermitRoadmap check for your specific project and answers. It returns the likely permits, documents, inspections, and next steps, each linked to its official source.
PermitRoadmap is an independent informational service and is not affiliated with any city, county, state agency, or permitting authority. Results are informational and do not replace confirming requirements with the local permitting authority.