Accessory Dwelling Units

What is an Accessory Dwelling Unit (ADU)?

An ADU is a residential living unit with complete independent living facilities, including a kitchen and bathroom, located on the same lot as a one- or two-family home.  It may take various forms including a detached unit; a unit that is part of an accessory structure such as a detached garage; or a unit that is part of an expanded or remodeled dwelling.

What are the requirements for an ADU?

The requirements for ADUs are established in Montclair Code §347-8. Key requirements include: 

  • ADUs are limited to properties containing one- and two-family homes in the R-O, R-O(a), R-1 and R-2 zones.
  • Either the ADU or the Primary Dwelling Unit must be the primary domicile of the person(s) who or entity that own(s) the property. In the case of a two-family home, the primary domicile of the owner must be one of the dwelling units or the ADU.
  • The ADU’s living area may not be more than 40% of that of the Primary Dwelling Unit, up to a maximum of 800 square feet; nor less than 300 square feet; and no more than three rooms, excluding the kitchen and bathroom.
  • There shall be no more than one ADU per lot and the ADU must meet the bulk requirements for the zone in which the property is located.

What is the process to create an ADU?

  1. Feasibility Study. The first step is to determine what type of ADU works on your property. You will need a property survey to determine the existing property dimensions and whether an attached or detached ADU is possible.
  2. Prepare a plan. If the ADU is detached or involves an addition to the existing building, a plan must be prepared showing the location, dimensions and elevations of the proposed ADU. If the ADU is internal to an existing building, than a floor plan must be submitted showing the footprint of the Primary Dwelling Unit and the footprint of the ADU. The plan must be prepared by a licensed architect or engineer.
  3. Zoning Permit. An application for a Zoning Permit for an ADU must be filled out, signed and submitted to the Department of Planning and Community Development along with the survey and plan. Within 10 business days after the application is deemed complete, the Zoning Officer shall schedule a meeting with the applicant to discuss the project. Within 10 days of this meeting, the Zoning Officer shall render a final decision and notify the applicant as to whether the ADU is approved.
  4. Construction. Once the zoning permit is issued, a building permit application and construction drawings must be submitted to the Building Department. The ADU cannot be occupied until a Certificate of Occupancy is issued by the Building Department.
  5. Deed Notice. All ADUs must file a deed notice with Essex County clearly indicating the presence of the ADU and the limitations of its use. A copy of the deed notice must be provided to the Department of Planning and Community Development. A Certificate of Occupancy cannot be issued until the deed notice is filed.

Are there any ongoing requirements for an ADU?

  1. Annual Affidavit. On or before January 1 of every year, starting with the first January following the issuance of the initial Certificate of Occupancy for an ADU, the Owner to whom the Certificate of Occupancy was issued must file an affidavit stating that there has been no change in the conditions upon which the ADU was originally approved. A sample affidavit form is provided in the Zoning Permit application. If the Owner fails to file the affidavit as herein required, the Certificate of Occupancy issued for the ADU shall automatically be revoked within 30 days, and the Construction Official shall so notify the Owner and the tenant, if any, in writing, of the revocation.
  2. Property Transfer. If the Owner of the property in which an ADU is permitted transfers title to the Property, the new Owner shall apply, as herein, for a Certificate of Continued Use of the ADU upon the terms and conditions contained herein. Such new application shall be filed within sixty (60) days of the transfer of the PropertyUpon the Construction Official determining that there have been no changes in condition, the Construction Official shall issue a new Certificate of Continued Use for the ADU upon the payment of a fee based on the current fee schedule for such issuance. An ADU may not be sold independent of the Primary dwelling unit. When listing the Property for sale with an approved ADU, the owner of the Property shall disclose to all prospective buyers that the property contains an approved ADU. The Township shall confirm same on the Certificate of Continued Use.