ADU Regulations in New Jersey: The Complete Guide

Affordable housing has been a struggle across the United States and New Jersey is no exception. However, that could change with the introduction of Accessory Dwelling Units, also known as ADUs. These compact, modular homes designed to provide additional living space on the same lot as a primary dwelling unit could be the solution. Interested in learning more? We dive right into the nitty gritty details of New Jersey ADUs and what the current regulations are for each county and major municipalities. 

Are ADUs Allowed in New Jersey?

Yes, but with some conditions. Currently, there is no statewide law permitting ADUs, and each municipality has to decide their own regulations for accessory dwelling units. However, there is a proposed bill in the works which would require all New Jersey municipalities to allow 1 ADU per single-family lot. This would significantly increase affordable housing options and make it easier for homeowners to invest in ADUs. Time will tell how this bill will play out, so keep an eye on it. 

What Is Considered An ADU in New Jersey?

New Jersey recognizes various types of ADUs, including garage and attic conversions, attached ADUs, and detached ADUs, but they all share some foundational concepts. The ADU must be an independent unit with its own entrance and have running water, sewage, and electrical systems. Space for sleeping, cooking, and living must be available. Some ADUs are required to have their own parking space and walkway. 

Can Park Model Tiny Homes Be Used As ADUs?

Park model homes, or tiny homes on wheels, are a smaller option for ADUs if you don’t have much space. They are built to all the standards of a certified RV, and are considered mobile, although they are designed to stay in one place most of the time. Because of this, New Jersey municipalities may not allow them as an ADU, which must have a permanent foundation. However, the best way to confirm the stance of park model homes as ADUs is to visit or contact your local zoning department with a copy of the plans, and ask them if this would be allowed. 

And if you don’t like what your municipality has to say about tiny homes, see what other states have to say about their use in the table below:

AL	IL	MN	NC	TX
AZ	IN	MS	ND	UT
AR	IA	MO	OH	VT
CA	KS	MT	OK	VA
CO	KY	NE	OR	WA
CT	LA	NV	PA	WV
DE	ME	NH	RI	WI
FL	MD	NJ	SC	WY
GA	MA	NM	SD
ID	MI	NY	TN

Can Log Cabins Be Used As An ADU?

Yes, log cabins can double as an ADU, provided your lot is in a more rural area with plenty of space. New Jersey caps most ADUs at 750-1200 square feet, and we have several gorgeous log cabins that fit into that range. 

Can Modern Cabins Be Used As An ADU?

Looking for a cabin feel, but don’t like the more rustic look? Don’t worry, we have sleek, modern options for you that combine the best of both worlds. These are ideal for ADUs because they match the architectural standards of many modern homes, while still retaining that cozy cabin feel. Again, make sure you choose a model that fits within the ADU limit, and you’ll be on your way to a brand new modern cabin ADU! 

What is the Difference Between a Prefab ADU & a Modular ADU?

The distinction primarily comes down to how the ADU is manufactured and assembled. Prefab ADUs are built almost entirely in the factory then delivered to the house site and installed on the foundation. Modular ADUs are created in sections, delivered and assembled together, which allows for minute adjustments and perfect alignment. 

What is the Minimum Size for an Accessory Dwelling Unit?

In the absence of a statewide law around ADUs, there are no minimum size requirements for ADUs in New Jersey. Across the United States, the general standard is anywhere from 200-400 square feet. 

Can My ADU be Bigger Than My House?

No, because ADUs are designed to create additional living space, not overpower the main unit. Many of New Jersey’s municipalities cap them at 50-75% of the primary dwelling, with the proposed bill capping them at 60%. 

How Close To My House Can I Build An ADU?

You will need to confirm with your local zoning department to know for sure, but the typical requirement for accessory buildings is a 7-10 foot rear setback and 3-5 ft side setback. 

Do You Need A Permit For An ADU in New Jersey? 

Yes.  Local zoning and construction departments control the permitting process. Homeowners should expect to apply for zoning approval, building permits, and inspections covering things like foundations, utilities, electrical, plumbing, and fire safety. Some towns streamline the process, while others treat ADUs similarly to small single-family homes, so timelines and requirements can vary.

Are There Any Incentives or Grants for ADUs in New Jersey?

Yes, New Jersey offers incentives and financing for ADUs, though they are not always advertised as direct grants. Certain municipalities participate in affordable housing or workforce housing programs that may provide low-interest loans, fee reductions, or tax incentives if the ADU is rented at an affordable rate. At the state level, programs tied to housing accessibility, aging in place, or energy efficiency may also apply, depending on how the ADU is used and built. Availability changes by location, so homeowners should check with local housing or planning offices.

What Features are Included in An ADU from Zook Cabins?

Zook Cabins’ ADUs include the core features needed for comfortable, full-time living. These consist of a finished living area, kitchen space, bathroom, bedroom or sleeping area, insulation suitable for year-round use, and standard electrical and plumbing systems. Layouts are designed to be efficient without feeling cramped, and our models can be customized to fit specific needs such as home offices, guest suites, or long-term rentals.

Are Zook Cabin’s ADUs Built to Code?

Absolutely! Our hardworking team takes care to ensure code compliance in all areas, and even exceeds the standards where we can. You won’t have to worry about an ADU from Zook Cabins not meeting code; you simply need to order and relax. Have more questions? Our team would love to answer them for you!

Can an ADU Have Multiple Bedrooms and Bathrooms?

They can if sizing allows. An ADU can have multiple bedrooms and bathrooms, but this is usually limited by local zoning rules, size caps, and occupancy limits. Many New Jersey towns restrict ADUs to one or two bedrooms to keep them clearly secondary to the main home. Larger ADUs may be allowed on bigger lots or under specific zoning districts, but homeowners should confirm allowable square footage and room counts before finalizing a design.

Are ADUs A Good Investment?

ADUs are generally considered a strong investment, especially in high-demand housing markets like much of New Jersey. They can generate rental income, increase overall property value, and provide flexible living options for family members or caregivers. While upfront costs and permitting can be significant, long-term returns often come from steady rental demand, lower vacancy rates, and the added versatility an ADU brings to a property.

What Counties in New Jersey Allow ADUs? 

Atlantic County	Regional Planning and Development
Bergen County	Planning and Engineering
Burlington County	County Planning
Camden County	Planning Department
Cape May County	Planning Department
Cumberland County	Planning Assistance
Essex County	Division of Planning
Gloucester County	Planning
Hudson County	Planning Department
Hunterdon County	Planning and Land Use
Mercer County	Planning and Zoning
Middlesex County	Office of Planning
Monmouth County	Planning Board
Morris County	Zoning
Ocean County	Department of Planning
Passaic County	Planning and Economic Development
Salem County	Planning Board
Somerset County	Planning Department
Sussex County	Planning and Zoning
Union County	Planning Board
Warren County	Zoning Enforcement

Does Atlantic County, NJ, Allow ADUs? 

Yes, but it is not decided at the county level. Atlantic County itself does not administer a county-wide accessory dwelling unit ordinance; ADU rules are set by the individual municipalities within the county. For ADUs, homeowners must consult the zoning code of the town where the property is located to determine whether ADUs are permitted, what minimum lot sizes and bulk standards apply, and what permit approvals are required by that municipality’s planning and zoning board. 

Does Bergen County, NJ, Allow ADUs?

 Bergen County does not have a unified county ADU ordinance; instead, accessory apartments and similar units are regulated by each municipality’s zoning code. In towns that permit ADUs, common limitations include minimum lot size thresholds (often 7,500 to 15,000 square feet depending on the zone, unit size limits (typically capped at roughly 30 to 40 percent of the primary dwelling or a maximum of 800 to 1,000 square feet), and owner-occupancy requirements for either the main house or the ADU. Specific dimensions and permit timelines vary by town, so property owners must review the local zoning ordinance and consult the municipal zoning officer for precise requirements.

Does Burlington County, NJ, Allow ADUs?

Just like all of New Jersey counties, Burlington County does not have a countywide accessory dwelling unit ordinance and leaves ADU regulation to municipalities. In Burlington County towns that allow ADUs, homeowners must follow the local zoning district’s lot and yard requirements and submit applications for zoning and building permits to the municipal planning and construction departments. Minimum unit sizes, maximum unit sizes, and other standards such as parking or owner-occupancy requirements are dictated by each municipality’s zoning ordinance rather than by county regulation. 

Does Camden County, NJ, Allow ADUs?

Here again, Camden County does not have a county-wide ADU ordinance because ADU rules are set by each municipality’s zoning and land use regulations. Because there is no county standard, homeowners must check the local municipal code to see whether ADUs are permitted, what minimum lot sizes and bulk standards apply, and what approvals are needed from local zoning and construction officials. In zones where ADUs are allowed, typical municipal requirements mirror traditional accessory building rules with additional conditions for independent living space. 

Does Cape May County, NJ, Allow ADUs?

Cape May County itself does not regulate accessory dwelling units at the county level; ADU provisions are handled by individual municipalities such as the City of Cape May. In Cape May’s municipal code, accessory apartments (a form of ADU) are permitted within or attached to the principal dwelling or within an existing accessory building that contains a dwelling unit, subject to state affordable housing regulations. Minimum floor area for an accessory apartment in the City of Cape May is 350 square feet, and units must contain living/sleeping space, kitchen facilities, and a complete bathroom. If you live in Cape May County, you should reach out to your local zoning department and ask them for more guidance. 

Does Cumberland County, NJ, Allow ADUs?

Yes, but not at the county level. Cumberland County does not have a county-wide ADU ordinance and zoning and ADU standards are established at the municipal level.  In towns within Cumberland County that permit ADUs, homeowners must follow the local zoning code’s bulk, lot, and yard requirements and apply for zoning and building permits through the municipal offices. Because town codes vary, ADU size limits, setback distances, owner-occupancy requirements, and parking rules are dictated by each municipality’s ordinance rather than a uniform county standard, so contacting the local zoning officer early in the process is essential.

Does Essex County, NJ, Allow ADUs?

Essex County does not have a unified county-wide ADU ordinance. However, several Essex municipalities such as Montclair and Maplewood have adopted local ADU standards, which include limits on the size of the ADU relative to the main dwelling and owner-occupancy requirements. For example, Montclair’s ordinance allows one ADU on lots with one- or two-family homes, caps ADU size at no more than 40 percent of the primary dwelling (up to about 800 square feet) with a minimum size of 300 square feet. Homeowners need to obtain a zoning permit and then a building permit, and must meet any annual certification or deed notice requirements imposed by the municipality. If you live within Essex County, we advise you to contact your local zoning or building department to see what they have to say. 

Does Gloucester County, NJ, Allow ADUs?

Gloucester County itself does not regulate ADUs at the county level. Individual towns in Gloucester County determine whether ADUs are permitted and what standards apply. In most municipal zoning codes, accessory structures are governed by rules that also apply to potential ADUs, including minimum distances from lot lines and from the principal building, but town ordinances must be consulted directly for specific ADU provisions.

Does Hudson County, NJ, Allow ADUs?

Like its neighbors, Hudson County does not have a countywide ADU ordinance that governs the entire county. Several cities in the county, including Jersey City and Newark, have begun adopting or updating local ADU regulations. Jersey City has amended its zoning standards to accommodate accessory dwelling units and incorporates ADU provisions into its zoning code. Newark’s ordinance allows one ADU per property, sets minimum and maximum unit sizes (for example, at least 400 square feet but not more than 600 square feet or 25 percent of the principal dwelling), and requires owner occupancy in either the principal residence or the ADU.  These municipal rules govern ADU development rather than any county-wide standard. We advise going directly to the local level instead of contacting county officials. 

Does Hunterdon County, NJ, Allow ADUs?

Hunterdon County does not have a county-wide accessory dwelling unit ordinance; ADU standards are governed at the municipal level.  In towns within Hunterdon that permit ADUs, homeowners must consult the local zoning code to determine whether ADUs are allowed, how large they can be relative to the primary dwelling, and what approvals are required from municipal zoning and construction departments. Some municipalities treat ADUs as accessory apartments within existing single-family homes or accessory structures, and they typically require additional compliance. For more information, go directly to the local level and call your town’s planning and zoning department. 

Does Mercer County, NJ, Allow ADUs?

When it comes to Mercer County, whether and how ADUs are allowed depends on municipal zoning within the county. Regulations in some Mercer municipalities indicate that multiple ADUs may be permitted on a residentially-zoned lot, with limits on the total accessory floor area not to exceed a percentage of the lot’s gross floor area and subject to the same setbacks and dimensional controls as other accessory buildings. ADUs in these areas are generally defined as small living units that may be attached or detached from the primary dwelling, and they must comply with the same zoning requirements for residential accessory uses. Because standards vary by municipality, we suggest that you reach out to your local zoning department for the most updated information. 

Does Middlesex County, NJ, Allow ADUs?

Middlesex County does not have a county-wide ADU ordinance that applies uniformly;instead, ADU permissions and requirements are set by individual municipal codes within the county. General guidance for ADUs in areas of Middlesex suggests that minimum lot sizes of 10,000 to 20,000 square feet are common in residential zones that permit ADUs, and that the accessory unit must be subordinate to the main dwelling in scale and appearance. Because these parameters are dictated by each town’s zoning ordinance, homeowners should review local codes and speak with the municipal zoning officer to determine specific size, setback, and permit requirements.

Does Monmouth County, NJ, Allow ADUs?

Not at the county level, but at the municipality level. In Monmouth County, ADU standards are set by the individual municipalities within the county. Several towns, including Asbury Park, have explicit ADU regulations that allow accessory units on single- and two-family lots subject to local zoning controls. In Asbury Park, for example, ADUs are permitted as an accessory use in certain residential districts with requirements that one of the units be the owner’s primary residence, a zoning permit and construction documents must be submitted before building, and rentals are limited to yearly leases (short-term rentals are prohibited). If you live in a town in Monmouth County, call your town’s zoning department and see what the process is for ADUs. 

Does Morris County, NJ, Allow ADUs?

Following the pattern of other New Jersey counties, Morris County does not enforce a uniform ADU ordinance at the county level. County planning reviews do not impose specific size, setback, or permit criteria for ADUs on residential lots, and in many Morris towns, ADUs are treated as conditional uses or require variance approvals under the local land use ordinance. 

Because there is no county-wide ADU standard, homeowners should check the local municipal zoning ordinance and engage with the municipal planning and zoning office early in the process. This will bring clarity to what is not clearly outlined in the zoning codes. 

Does Ocean County, NJ, Allow ADUs?

Ocean County does not have a county-wide accessory dwelling unit ordinance; ADU policies are established by the individual municipalities within the county. In most Ocean County towns, ADUs must comply with the zoning district’s bulk and yard standards, and there is no unified county standard on maximum unit size, setbacks, owner-occupancy, or parking. Without a county standard, local municipal zoning officers are the definitive source for the precise ADU requirements in any Ocean County community. 

Does Passaic County, NJ, Allow ADUs?

While it isn’t decided at the county level, the City of Passaic defines an accessory dwelling unit as a living unit within or attached to a single-family or two-family dwelling that provides independent living facilities, and only one ADU is allowed per lot. The unit may not exceed 50 percent of the living area of the principal dwelling and must be at least 300 square feet in area, with no more than three bedrooms. ADUs must be located within an attic, basement, ground floor below the principal unit, or above a garage, use the same exterior materials as the principal building, and not eliminate required on-site parking. This is one example of a municipality in Passaic County allowing ADUs. 

Because each municipality in Passaic County sets its own rules, homeowners must consult the local zoning code and planning/zoning office for additional requirements such as setbacks, owner-occupancy conditions, and the sequence of zoning and building permits.

Does Salem County, NJ, Allow ADUs?

At the county level, there isn’t clarity.  In the City of Salem, the zoning code does not explicitly list detachedADUs as a permitted residential use in residential districts, and traditional accessory buildings like garages are regulated under standard accessory building rules without specific provisions for full living units. Salem’s residential district standards include minimum lot and yard requirements, but there is no clear local ADU provision in the base zoning code allowing new detached ADUs as a permitted use. 

Because local codes vary across Salem County municipalities, homeowners should contact the local planning and zoning department early in the process to determine whether ADUs are permitted in their specific town and what size, setback, owner-occupancy, and permit requirements apply. 

Does Somerset County, NJ, Allow ADUs?

Somerset County does not have a county-wide accessory dwelling unit ordinance; ADU permissions and standards are set by each municipality’s zoning code. In municipalities such as Bridgewater Township, the zoning code does not specifically outline ADUs as a permitted use in the use regulations, so ADUs must be reviewed under local definitions. Generally, where a municipal code allows ADUs, they must meet the underlying residential zone’s yard requirements (such as lot area, setbacks, and height), and homeowners are required to obtain zoning clearance and a building permit before construction. Because these parameters are dictated by each town’s adopted zoning ordinance, property owners should consult the local zoning officer to find out more information. 

Does Sussex County, NJ, Allow ADUs?

The county’s master planning and development guidance does not set specific ADU size, setback, or permit standards that apply across all towns. Instead, municipal zoning codes in Sussex County govern residential uses, typically through minimum lot sizes and setback requirements for all buildings, but they do not generally include a county-wide ADU use category. 

Homeowners should consult their town’s zoning ordinance to determine whether ADUs are permitted and what maximum unit sizes and dimensional requirements apply. In most Sussex municipalities, accessory living spaces must satisfy the same lot area and setback rules that apply to principal and accessory structures, and each town’s zoning officer is the definitive source for ADU compliance.

Does Union County, NJ, Allow ADUs?

 It isn’t decided at the county level. Union County does not administer a county-wide ADU ordinance and local municipalities can have the power to decide.  For example, Union Township’s zoning code specifically permits accessory dwelling units in its RA and RB residential zones on lots of at least 5,000 square feet, allows only one ADU per lot, and requires that the unit be located within an owner-occupied dwelling. Also in Union Township, the ADU must include a full kitchen and bathroom, and have at least one off-street parking space. Other Union County municipalities have their own ADU provisions or may not permit ADUs at all, so homeowners must review the specific municipal ordinance and secure both zoning and building permits through the local planning and construction offices before proceeding. 

Does Warren County, NJ, Allow ADUs?

It is unclear at this point. Like many other New Jersey counties, Warren County does not have a county-wide accessory dwelling unit ordinance; ADU regulation is left to local governments within the county. The county planning department provides broader land use guidance and master planning, but it does not establish uniform ADU size, yard, or permit criteria. Municipal zoning ordinances in Warren County vary, and many do not yet include specific ADU use provisions, meaning ADUs may be treated as part of conditional use categories or require variance approvals under local land use regulations. Homeowners interested in building an ADU should contact their local municipality’s zoning office to determine whether ADUs are permitted and what process they need to follow to have them approved. 

Accessory Dwelling Unit Requirements by Municipality 

Jersey City	Housing and Development
Union City	Building Department
Atlantic City	Planning and Development
Neptune Township	Zoning and Code Enforcement
Ocean City	Zoning Services

Does Jersey City, New Jersey, Allow ADUs? 

Yes, Jersey City has clear standards for ADUs, making it easier for interested homeowners. ADUs are allowed under its local zoning regulations, and the city has updated its code to explicitly accommodate ADUs on lots where single-family and two-family homes are permitted. According to the city’s zoning guidance, a detached ADU may be added on a lot in many residential zones such as R-1, R-2, RH-1, and RH-2, and one ADU is permitted in addition to the units in the principal structure. Although Jersey City’s code does not impose a strict maximum square footage for ADUs, there are height limits (up to 18 feet or two stories) and setbacks and lot coverage standards that vary by zone which effectively influence the size and placement of an ADU. 

Jersey City also processes ADU permits through its online zoning and permitting portal, and applications must comply with local building, fire, and zoning requirements in Chapter 345 of the Municipal Code. For complete details on permitted zones and specific dimensional standards, the city’s zoning regulations provide tables showing side yard, rear yard, height, coverage, and other bulk requirements by zone. To proceed, contact the Building Department and get more clarity on the permit process. 

Does Union City, New Jersey, Allow ADUs? 

It is unclear at this point. Union City’s zoning code does not currently include a clear provision that allows ADUs for living in accessory buildings. The municipal ordinance states that accessory buildings cannot be used for human habitation and limits detached accessory structures to a maximum of 500 square feet or one-third of the principal building’s area, whichever is greater, with specific setbacks from property lines and other restrictions. Because of this language, true ADUs that would qualify as separate dwelling units are not expressly permitted under the standard accessory structure rules, and any attempt to establish an ADU may require a variance or special approval from the zoning board. 

Does Atlantic City, New Jersey, Allow ADUs?

It is likely, but it will require some effort. Atlantic City’s zoning code allows accessory uses and structures in its residential districts, and detached accessory buildings may be sited in rear yards subject to yard setbacks and bulk limits, but it does not yet have a clear, dedicated ADU provision that defines ADUs as independent dwelling units with kitchens and bathrooms in all residential zones. This means a variance or conditional use permit is required for them to be allowed. Detached accessory structures in residential districts must meet location, setback, and coverage standards described in the Residential Land Use Schedule and Section 163 of Atlantic City’s ordinance, but the code does not yet explicitly treat accessory dwelling units as a permitted use. Call the local zoning or planning department to find out more information. 

Does Neptune Township, New Jersey, Allow ADUs? 

They sure are! ADUs are recognized in the municipal land development and zoning ordinance but only under specific conditions and not broadly allowed everywhere like in some other cities. The township’s zoning code defines an accessory apartment as a self-contained residential dwelling unit with its own kitchen, bathroom, sleeping area, and private entrance which can be created within an existing residence or by addition to the main house or an accessory building. 

In Neptune Township, ordinary single-family zones list detached single-family residences as the permitted use and accessory apartments appear specifically referenced under conditional use sections for certain districts rather than normal residential districts. Because of this, an ADU in Neptune Township typically requires a conditional use approval or variance process through the local land use board rather than being allowed by right. 

The specific size, setback, and parking requirements will depend on the zoning district and conditions placed by the board during approval. For the most accurate, up-to-date details on dimensional standards and whether an ADU is allowed on a specific property, reviewing the zoning codes of the Neptune Township Land Development Ordinance and consulting the full Neptune Township LDO is necessary. 

Does Ocean City, New Jersey, Allow ADUs? 

Yes, Ocean City does allow accessory apartments, which function as ADUs, but only in specific zoning districts such as R-2 and RMF, and they are subject to detailed area and unit requirements. In Ocean City, an accessory apartment must have a gross floor area of at least 450 square feet and not more than 950 square feet, contain a full kitchen and bathroom, have a separate exterior entry, and conform to the applicable parking and building code provisions. Only one accessory apartment is permitted per lot, and the unit and its structure must comply with other zoning standards such as lot coverage, setbacks, and use eligibility. For more information, peruse the zoning codes or call the zoning department to start the next step. 

Searching for an ADU Builder Serving New Jersey?  

Now that you’ve made it this far, you’re ready to take the next step! Find an ADU builder that you can trust with upfront pricing and an established process because this will make the whole journey much easier. Zook Cabins is pleased to offer New Jersey our ADU services, wherever these accessory dwelling units are allowed. We are passionate about what we do and want to make ADUs available to you. Contact us or request a free quote to get the process started!