ADU rules in Monmouth Beach

Monmouth Beach's Land Use and Development Regulations (Chapter 30) allow no detached accessory dwelling. An accessory building is defined so that 'any building or structure with a floor area in excess of 900 square feet or a building or structure containing living space shall never be considered an accessory' (§ 30-2.3, as amended 9-19-2023 by Ord. No. O-08-23), the same section deems 'any dwelling' a principal building, and § 30-5.9 allows a single- or two-family lot only one principal building. The residential districts' accessory uses are a closed list of private garages or carports, fences and walls, private pools, signs and small wind and solar systems (Schedule of Limitations), and § 30-5.2E admits no use a district does not list. The Unified Planning and Zoning Board of Adjustment holds that line: its 4-25-2023 approval of a two-story garage at 13 Riverdale Avenue was conditioned that the structure 'shall not be used as or for a separate dwelling unit, now or in the future', its 5-27-2025 approval of a garage and pool cabana at 1 Shrewsbury Drive was granted on testimony that the cabana would be unheated, have no kitchen and serve only as storage in winter, and a 2023 resolution denied a d(2) variance to raise and expand an existing second dwelling at 18 Valentine Street. A cottage, carriage house or garage apartment therefore needs a d(1) use variance.

No district permits a second unit inside or attached to a house. The A and A-1 Single-Family Residential districts permit as principal uses only single-family homes, public buildings and uses and cottage food operations, and the A-2 and A-3 districts add only high-rise apartments or garden apartments and townhouses on 80,000 square foot tracts (Schedule of Limitations; §§ 30-8.19.1 and 30-8.19.2). A single-family dwelling is 'a building designed for or containing one dwelling unit' (§ 30-2.3), no district lists two-family dwellings, and a use not listed is a 'prohibited use' that needs a variance under N.J.S.A. 40:55D-70d (§§ 30-2.3, 30-5.2E). Chapter 30 does define 'accessory apartments' in its Fourth Round affordable housing article (§ 30-10.2, Ord. No. O-04-26, adopted 3-10-2026: units within the house, within an accessory structure, built as an extension or detached, 'also referred to as "accessory dwelling units"'), but § 30-10.5A.2 states that 'The Borough of Monmouth Beach does not have an accessory apartment program in its current HESP', and neither version of the Fourth Round plan (May 2025, updated 1-29-2026) nor DCA's 7-1-26 status report lists one. A basement, attic or in-law apartment with its own kitchen therefore needs a d(1) use variance, while relatives living as one housekeeping unit in the house are a single 'family' (§ 30-2.3) and need no approval.

Because Chapter 30 recognizes no ADU, it sets no accessory-unit size; the binding envelope for anything built behind a house is § 30-5.8 and the Schedule of Limitations. Accessory buildings may not occupy more than 35 percent of a required rear or side yard or exceed 1,200 square feet of combined building coverage, no one accessory building may exceed 900 square feet, and none may exceed 18 feet or one story (§ 30-5.8B; Schedule of Limitations); detached ones stay out of the front yard, at least 5 feet from every lot line (3 feet for sheds under 100 square feet) and 5 feet from the house, and none may be permitted before the house (§ 30-5.8A, C and F). A one-car garage must be at least 300 square feet, and the lesser of half a detached garage's floor area or 150 square feet is left out of coverage (§ 30-5.8E). Houses are capped at 35 feet (38 feet in a special flood hazard area where the lowest floor sits 36 inches above base flood elevation), 27 percent building coverage and 40 percent total lot coverage, on minimum lots of 15,000 square feet in A and 9,000 in A-1 (11,000 and 7,500 beside a navigable waterway), with minimum livable floor areas of 1,300 to 2,300 square feet in A and 1,000 to 1,600 in A-1 (Schedule of Limitations; § 30-2.3 Building height).

Monmouth Beach authorizes no ADU, so there is no accessory-unit owner-occupancy rule to report, and nothing in Chapter 30's district rules conditions a house on its owner living there. The nearest owner-related provisions are in the 2025 short-term rental chapter, whose 'owner-occupied' definition reaches 'the principal residential unit with which the STRP is associated on the same lot' and which lets one unit of a two-family dwelling, or up to two units of a multifamily dwelling, be rented short term only while the owner lives in another unit as a principal residence (§§ 23-2, 23-3b), and in the Fourth Round development fee section, which exempts improvements to 'owner-occupied property in which there is located an affordable accessory residence' during its affordability controls (§ 30-10.17C.2.f), an exemption with no program behind it. New Jersey has no ADU statute, so no state rule would bar an owner-occupancy condition if the borough adopted one.

§ 30-8.21O.12 (as amended 9-19-2023 by Ord. No. O-08-23) requires 'Two parking spaces for each single-family dwelling, one of which shall be enclosed' and two spaces for each unit in multiple-family dwellings, on the same lot as the use (§ 30-8.21I.4); a parking space is at least 200 square feet (§ 30-2.3) and a one-car garage at least 300 square feet (§ 30-5.8E). The state Residential Site Improvement Standards govern site improvements for residential development (N.J.A.C. 5:21-1.5(a)), are 'the maximum that may be required in connection with residential development' (5:21-1.5(b)), and make Table 4.4 'the maximum number of parking spaces planning boards and other local reviewers shall require' (5:21-4.14(c)): a single-family detached house needs 1.5 spaces for two bedrooms, 2.0 for three, 2.5 for four and 3.0 for five, and each duplex unit the same values. The borough's flat two-space rule therefore exceeds the state ceiling for a two-bedroom house, although a one-car garage with an 18-foot driveway already counts as 2.0 spaces (5:21-4.14(d)2). Short-term rental guests are limited to one vehicle per four occupants (§ 23-5a(6)).

No district lists an accessory dwelling as a permitted or conditional use; the conditional uses are public utilities, schools, churches, child care centers, marinas, yacht and beach clubs, a professional office building and a gasoline station mini mart (Article 30-9; Schedule of Limitations). A second unit on a house lot is 'a use or principal structure in a district restricted against such use or principal structure', which § 30-3.2B.1(d) sends to the Unified Planning and Zoning Board of Adjustment (the Planning Board exercising Board of Adjustment powers under N.J.S.A. 40:55D-25(c), § 30-3.2A.1) as a use variance that 'shall be granted only by affirmative vote of at least five members of the Board', with the Class I (Mayor) and Class III (commissioner) members barred from sitting; the fee is $100 with a $1,000 escrow (§ 30-3.4O), and an approval can be appealed to the Board of Commissioners within 10 days of publication (§ 30-3.2E.1). The Board's 2026 agendas (January 6 through October 27) list bulk c variances, minor subdivisions, an extension of time, two denials and the Fourth Round plan, and no use variance for a second unit. A conforming addition or accessory building needs only a Zoning Permit ($750 for new homes and additions, $100 otherwise) and a construction permit (§ 30-5.29C.2 and H.2), since construction related to a single-family detached dwelling is exempt from site plan review (§ 30-2.3 Exempt development).

Rental rules sit outside zoning. Chapter 23 (Ord. No. O-03-25, adopted 4-23-2025) defines a short-term rental as occupancy by someone other than the owner or permanent resident 'for a period of 90 days or less consecutive days' and requires 'a minimum stay period of seven consecutive days'; it allows them in single-family houses, condominium units whose association permits them, one unit of a two-family dwelling or up to two units of a multifamily dwelling where the owner lives in another unit, never for a room sharing a kitchen and bath with a non-owner occupant (§§ 23-2, 23-3). The owner (never a tenant) must hold an annual $500 permit and a rental certificate of occupancy from the Municipal Clerk, a zoning compliance certificate and $500,000 of liability insurance ($300,000 for an owner-occupied building of four or fewer units), pass inspections every three months, print the permit number in every listing, report each new group of occupants, rent under one contract at a time to a primary occupant over 18, and limit guests to one vehicle per four occupants; bookings through a platform (and units of multi-unit operators) owe a 3 percent municipal tax under N.J.S.A. 40:48F-1, and violations run from a warning to $2,000 and revocation (§§ 23-4, 23-5, 23-7, 23-8, 23-9). Every sale, lease or rental, 'temporary or permanent', also needs a Certificate of Code Compliance from the Housing Official ($100 per single-family rental unit, granted or denied within 10 days, § 15-4.1) and a smoke and carbon monoxide alarm certificate at each change of occupant ($100, or $161 on less than four business days' notice, § 16-9b). Chapter 13 (Ord. No. O-08-25, adopted 7-23-2025) bars any property, accessory buildings included, from use as a boarding or rooming house.