Maplewood ADU Zoning Guide

Last reviewed 2026-04-28

Max size800 sq ft
Owner occupancyRequired

Maplewood, NJ permits accessory dwelling units in single-family residential zones under Chapter 271, Article IX of the township code (added by zoning amendment in late 2020). The ordinance allows one ADU per lot in the R-1-4, R-1-5, R-1-7, and R-2-4 districts, capped at 800 square feet and 40% of the principal dwelling. Either the principal home or the ADU must be the owner's residence, and basement ADUs are not permitted.

Status

Adoption status: Active — Maplewood added Article IX (Accessory Dwelling Units) to Chapter 271 in late 2020 as a zoning amendment
Governing ordinance: Township of Maplewood Code, Chapter 271 (Zoning and Development Regulations), Article IX (Accessory Dwelling Units)
Key differentiator: Owner-occupancy is mandatory and basement/cellar ADUs are prohibited; historic-district properties require a certificate of appropriateness

Eligibility

Where ADUs are allowed

Zoning districts permitted: R-1-4, R-1-5, R-1-7, and R-2-4 single-family residential zones
Lot type / use restrictions: Permitted on single-family residential lots; one ADU per lot; not permitted on historic-designated properties without a certificate of appropriateness from the Historic Preservation Commission
Limit per property: Maximum of 1 ADU per lot

Types allowed

Attached ADU (interior conversion — basement/attic): Basement/cellar NOT permitted; above-grade interior conversions allowed
Attached ADU (addition): Yes — must use the same exterior materials and colors as the principal dwelling
Detached ADU (new construction): Yes
Detached ADU (accessory structure conversion — e.g., garage): Yes
Entrance restriction: An attached ADU may not have a separate street-facing entrance

Size and placement

Size limits

Maximum sq ft: 800 sq ft
Maximum percentage of principal: 40% of the principal dwelling's living area
Minimum sq ft: 300 sq ft
Maximum bedrooms: 2
Maximum occupants: 3 persons

Setbacks

Location restriction: ADU may not be located in a cellar; must be above grade
Setback requirements: Standard accessory-structure and zone bulk requirements apply for the relevant R-district

Rules for use

Owner occupancy

Required: Yes — either the ADU or the principal dwelling must be the domicile of the property owner
Separate sale permitted: No — the ADU cannot be sold independently of the principal dwelling

Rental use

Short-term rental: Not specifically authorized by the ADU ordinance; general Maplewood STR rules apply
Long-term rental: Permitted, subject to owner-occupancy of either the principal or the ADU
Separate sale: Not permitted

How to apply in Maplewood

Zoning approval: Required from Maplewood Zoning Division (Chapter 271, Article IX)
Building permit: Required under the New Jersey Uniform Construction Code
Historic district overlay: Properties designated as historic require a certificate of appropriateness from the Historic Preservation Commission

Recent and pending changes

Late 2020
Maplewood added Article IX (Accessory Dwelling Units) to Chapter 271 of the township code, permitting ADUs in R-1-4, R-1-5, R-1-7, and R-2-4 zones

Important details

Three-person occupancy cap: An ADU may be occupied by no more than three persons
No street-facing separate entrance: ADUs cannot have an entrance directly on the street
Historic preservation overlay: Historic-designated properties require a certificate of appropriateness from the Historic Preservation Commission before an ADU can be approved
Material harmony: An attached ADU must use the same exterior materials and colors as the principal dwelling

Frequently asked questions

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

Yes. Either the principal dwelling or the ADU must be the domicile of the property owner under Chapter 271, Article IX. The ADU cannot be sold separately from the main house.

What's the maximum size for an ADU in Maplewood?

An ADU is capped at 800 square feet, no more than 40% of the principal dwelling's living area, with a minimum of 300 square feet, no more than two bedrooms, and no more than three residents.

Can I convert my basement into an ADU in Maplewood?

No. The Maplewood ordinance prohibits cellar locations for ADUs. Above-grade interior conversions, additions, garage conversions, and detached new construction are all permitted, but basement units are not.

Sources (4)

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