ADU rules in Berkeley

Berkeley's Land Development chapter (Chapter 35) has no accessory dwelling unit, accessory apartment, guest house or garage apartment provision, and it is an exclusive-permission code: § 35-89.2 bars any use or occupancy "except as indicated in each zone under permitted use." Every single-family district, from the small-lot R-31.5, R-50, R-60 and R-64 zones (the R-31.5, R-50 and BR Beachfront Residential districts mapped on the barrier island lay in South Seaside Park, which became part of Seaside Park in April 2026) through R-90, R-100, R-125, R-150, R-200, R-400, the Conservation/Residential and Public Preservation/Conservation zones and the R-400 PRRC retirement communities, permits detached single-family dwellings "together with their accessory structures", and § 35-89.4 allows no more than one residential building per lot outside the R-MF, R-4F, R-TH and R-LR districts. In the Pinelands Area zones of western Berkeley, § 35-89.17 allows only one principal use per lot. The only detached accessory dwelling the code mentions is a dwelling for an operator or employee of an active farm on a lot of at least 10 acres in the Pinelands Agricultural Production (AP) zone (§ 35-110.9c.2), which is farm housing, not an ADU.

The same use lists rule out an internal, basement or attached unit. A single-family dwelling is one "designed for and occupied exclusively by one family or containing one dwelling unit" (§ 35-3), and a dwelling unit is separate living quarters with its own cooking, sleeping and sanitary facilities, so adding a second such unit inside or onto a house makes it a two-family dwelling, which no single-family district lists. Chapter 35 still lists two-family dwellings as a principal use in the R-4F (Residential One- to Four-Family) district, on lots of at least 5,000 sq ft with 50 ft of frontage and a central sewer connection (§ 35-96.6), and in the R-TH district, which adopts every R-4F use (§ 35-96.7a.1), but both districts were mapped only in South Seaside Park, which became part of Seaside Park in April 2026. Within today's township, two-family dwellings are a principal use only on the mainland, in the Town Center Residential Subdistrict ("Single-family semi-detached dwellings, such as patio homes and duplexes", § 35-104.2d) and the R-MF portion of the TC-2 overlay (§ 35-106.6a.3). Those are duplexes built or converted as a principal use, not accessory units; the mainland's former Residential Two Family Zone (§ 35-96.5) was repealed in its entirety by Ord. No. 2015-22-OAB.

Because Chapter 35 authorizes no accessory dwelling, it sets no ADU floor-area, percentage or bedroom cap. The envelope for anything built in a yard is § 35-89.7 and Schedule 1 (35 Attachment 5, Supp 7, Dec 2025): accessory buildings may not exceed 15 feet, "shall occupy no more than 25% of the available front yard in a residential or rural zone" (the text says front yard even though detached accessory buildings may not stand forward of the house's front line), and an accessory building joined to the house by a covered passageway or a shared wall counts as part of the principal structure and must meet principal setbacks. § 35-3 requires an accessory structure to be "subordinate in area, extent and purpose" to the principal building, and the Zoning Office's permit packet tells applicants that accessory structures or uses cannot exceed the principal structure or use in size or scope. Chapter 35's R-4F duplex table (5,000 sq ft lot, 50 ft frontage, 35 ft height) governed the barrier-island duplex route, whose land passed to Seaside Park in April 2026, so it now applies to no Berkeley lot.

Chapter 35 attaches no owner-occupancy condition to any accessory unit because it authorizes none, so the directory records not-applicable rather than no. The nearest owner-related rules sit elsewhere: the Liability Insurance Registry (§ 5-31.2, Ord. No. 23-03-OAB) gives owner-occupied multifamily homes of four or fewer units a lower insurance minimum ($300,000 instead of $500,000), and the Pinelands cultural-housing and substandard-lot exceptions (§§ 35-89.15, 35-89.16) require a new detached house to be the principal residence of the owner or an immediate family member, a rule for a principal dwelling on its own lot, not an ADU. In the age-restricted PRRC communities, § 12-3.5e withholds the certificate of compliance for any sale, transfer or rental until the homeowners' association confirms the 55-and-over occupancy rules are met. New Jersey has no statewide ADU statute that would impose or preempt an owner-occupancy rule.

§ 35-89.12 sets the township-wide residential minimum, so a lawful second unit carries its own two-space requirement, and § 35-63.13f requires the parking to be on the same lot as the use it serves. The section's cross-reference to "Subsection 35-63.18" points nowhere (§ 35-63 ends at § 35-63.14), and the Town Center Residential Subdistrict and the TC-2 overlay instead tie residential parking to the state Residential Site Improvement Standards. The R-TH townhouse rule (two spaces per unit plus one guest space for every five units, § 35-96.7a.2(g), (i)) now governs no Berkeley land. There is no transit-proximity reduction or ADU exemption anywhere in Chapter 35.

There is no ADU permit path: no district lists an accessory dwelling as a permitted or conditional use (none of the Article XIII conditional uses is an accessory or second dwelling), and § 35-131.1a.2 bars the Zoning Officer from granting a permit for any building or use "that would be in violation of this chapter." A second dwelling unit on a single-family lot would need a use variance from the Zoning Board of Adjustment for "a use or principal structure in a district restricted against such use", which takes the affirmative vote of at least five members (§ 35-6.10d), with a $500 application fee (§ 35-8b.7(d)) plus the $2,500 residential use-variance amount listed in § 35-11f. Where a duplex is a permitted use (now only the mainland Town Center areas, since the R-4F and R-TH districts lay in South Seaside Park), single-family and two-family residential uses are exempt from site plan approval (§ 35-28), so a conforming duplex runs through a $30-per-unit zoning permit from the Zoning Officer (§§ 35-29a.4, 35-13b), which the township says it processes within ten business days, and then construction permits.

§ 12-3.5a bars a tenant from occupying a single-family dwelling or a unit of a multifamily dwelling until a certification of compliance is issued (reinspections $50), and the township's Rental / Resale Inspections page confirms the certificate is needed every time the tenant changes. § 12-3.5b lets short-term rental units go without heat if occupied only from April 15 to October 15 and caps occupants under Section 404 of the 2015 International Property Maintenance Code. § 5-31.2 (Ord. No. 23-03-OAB) requires every rental owner to file a certificate of insurance by January 1 each year, which the Clerk takes with the landlord registration form; § 12-6 requires lead-based paint inspections of pre-1978 rental units at tenant turnover or every three years (seasonal single- and two-family rentals of under six months a year are exempt); and § 12-5 lets a hearing officer require the landlord of a building with four or fewer units to post a $500 to $5,000 bond after two substantiated disorderly-conduct convictions within 24 months. Rentals in the age-restricted PRRC communities need the homeowners' association's written approval (§ 12-3.5e), and units in R-LR low-rise developments may be leased only for terms of at least 12 months (§ 35-96.8a.2(h)).