Montclair ADU Zoning Guide

Last reviewed 2026-04-28

Max size800 sq ft
Owner occupancyRequired

Montclair, NJ permits accessory dwelling units in its R-O, R-O(A), R-1, and R-2 zones under Chapter 347, §347-8 of the township code (Ordinance O-22-27, adopted February 22, 2023). One ADU is allowed per lot on properties with one- and two-family detached homes, sized between 300 and 800 square feet. The owner must occupy either the principal dwelling or the ADU, and short-term rentals are prohibited.

Status

Adoption status: Active — Ordinance O-22-27 adopted February 22, 2023, codified at Chapter 347 §347-8
Governing ordinance: Township of Montclair Code, Chapter 347 (Zoning), §347-8 (Accessory Dwelling Units)
Key differentiator: Restricted to detached one- and two-family homes in R-O / R-O(A) / R-1 / R-2 zones; short-term rental use is explicitly prohibited

Eligibility

Where ADUs are allowed

Zoning districts permitted: R-O, R-O(A), R-1, R-2
Lot type / use restrictions: One- or two-family detached homes only; attached/townhouse housing types are excluded
Limit per property: Maximum of 1 ADU per lot

Types allowed

Attached ADU (interior conversion): Yes
Attached ADU (addition): Yes
Detached ADU (new construction): Yes
Detached ADU (accessory structure conversion — e.g., garage): Yes
Architectural conformance: Must harmonize with the architectural and landscaping character of the neighborhood

Size and placement

Size limits

Maximum sq ft: 800 sq ft
Minimum sq ft: 300 sq ft
Maximum rooms: 3 rooms plus kitchen and bathroom

Setbacks

Setback requirements: Standard zone bulk requirements apply; specific dimensional limits set in §347-8 (a 2025 council update was under consideration to expand permissible structure dimensions — verify current limits)

Rules for use

Parking

ADU parking requirement: One off-street parking space, in addition to the parking required for the principal dwelling

Owner occupancy

Required: Yes — the property owner must reside in either the principal residence or the ADU
Separate sale permitted: No — the unit cannot be bought or sold separately

Rental use

Short-term rental: Prohibited — Airbnb, VRBO, and other short-term rental use is not allowed for ADUs
Long-term rental: Permitted, subject to owner-occupancy of either the principal or the ADU
Separate sale: Not permitted

How to apply in Montclair

Zoning approval: Required from Montclair Department of Planning & Community Development
Building permit: Required under the New Jersey Uniform Construction Code
Contact: Department of Planning & Community Development, 973-509-4954

Recent and pending changes

2023-02-22
Township Council unanimously adopted Ordinance O-22-27 on second reading, permitting ADUs in the R-O, R-O(A), R-1, and R-2 zones
2025-03
Township Council considered an update to §347-8 to expand permitted structure dimensions; verify current text with the township before applying

Important details

Detached one- and two-family homes only: Attached/townhouse housing is excluded from ADU eligibility
Short-term rental prohibition: Montclair §347-8 explicitly prohibits Airbnb-style use of ADUs
Architectural harmony: ADUs must harmonize with the architectural and landscaping character of the neighborhood

Frequently asked questions

Do I need to live in my Montclair home to build an ADU?

Yes. Under Montclair §347-8, the property owner must reside in either the principal residence or the ADU. The two units must remain in common ownership and cannot be sold separately.

What's the size range for an ADU in Montclair?

Between 300 and 800 square feet, with a maximum of three rooms plus a kitchen and bathroom. Only one ADU is allowed per lot, and it must be on a single- or two-family detached-home lot in the R-O, R-O(A), R-1, or R-2 zones.

Can I list my Montclair ADU on Airbnb?

No. Montclair's ADU ordinance prohibits short-term rental use. The ADU may be rented to long-term tenants only — short-term platforms like Airbnb and VRBO are not permitted.

Sources (4)

Last reviewed 2026-04-28. Local rules can change — verify the latest details with the Montclair planning department, or book a free consultation with our team before starting your project. This page is informational and is not legal advice.