ADU Pass
Franklin
ADU Pass helps homeowners in Franklin, Sussex County, New Jersey navigate the permit paperwork for building an accessory dwelling unit. This area covers 2 ZIP codes.
Map
ADU details
ADU legality: allowed
Franklin Borough processes ADUs under Chapter 161 use tables; statewide A1671 ministerial preemption applies. Highlands Preservation Area parcels require additional Highlands Council resource-area review; Highlands Planning Area parcels follow conforming local plan.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 300 | $2,200 | $78,000 | $80,200 |
| 600 | 600 | $2,900 | $192,000 | $194,900 |
| midpoint | 750 | $3,300 | $240,000 | $243,300 |
| maximum | 1,200 | $4,600 | $396,000 | $400,600 |
Fee breakdown (as of 2026-04)
Permitting process
- Pre-application zoning verification (~7d)
Confirm parcel zoning per Chapter 161 Article V (R-1, R-2, R-3 residence districts; C-1 conservation overlay). Identify whether parcel is in Highlands Preservation Area or Planning Area via Highlands Council parcel map. - Highlands Council review (Preservation Area parcels only)
Highlands Preservation Area parcels require Highlands Applicability Determination (HAD); if regulated, full Highlands Preservation Area Approval (HPAA) needed. Adds 60-180 days when triggered. - Septic system review (well/septic parcels) (~21d)
NJDEP / Sussex County Health Department review of septic system capacity for additional dwelling unit. Field test (perc test) may be required. Many Franklin parcels rely on private well/septic. - UCC construction permit application (~1d)
Submit NJ DCA Construction Permit Application (UCC F100) to Franklin Borough Construction Office at the Municipal Building, 46 Main Street. Include site plan, well/septic location, NJ-licensed design professional seal. - Tax-current certification (~3d)
Tax Collector must certify all taxes/assessments current before permit issues per NJ UCC. - Plan review (UCC subcodes + zoning) (~25d)
Building, electrical, plumbing, fire subcode review plus Zoning Officer compliance review. Rural borough volume is low; typical cycle 25 days. - Permit issuance (~2d)
All approvals + tax-current cert + (if applicable) Highlands HAD/HPAA + septic approval; subcode and DCA training fees paid; permit issues. - Construction inspections
Footing, foundation, septic-field (when applicable), framing/rough MEP, insulation, final. Inspections via Borough Construction Office. - Certificate of occupancy (~5d)
Final inspections cleared; CO issued.
Viability (permitted uses)
- Long-term rental: yes (Chapter 161) Long-term rental of ADU permitted in residence districts. Borough does not have rent control.
- Short-term rental: with-restrictions (Franklin Borough rental property regulations) Franklin Borough has not adopted a dedicated STR ordinance; ADU short-stay rental operates under NJ statewide rental and tax regime. Tourism demand from Sussex County mining heritage / Mountain Creek ski-area visitors.
- Rental registration with Borough may apply
- NJ State Sales & Hotel-Motel Occupancy taxes for stays under 90 days
- Highlands resource-area parcels may have additional restrictions
- Office rental: no Chapter 161 limits ADU to dwelling-unit use; commercial office requires separate use approval.
- Home office: yes Home occupation permitted in Chapter 161 with limits on customer traffic and signage.
- Studio / workshop: yes Personal artist/maker studio is a permitted accessory residential use.
- Agriculture: yes (NJ Right to Farm Act / Chapter 161 agricultural districts) Franklin Borough has agricultural zones; backyard agriculture, beekeeping, and small livestock allowed in those zones. Residential ADU-adjacent agriculture limited by district.
- Relative support: yes Family-occupancy ADU explicitly permitted; common arrangement for aging-in-place in rural Sussex.
Incentives
- NJHMFA First-Time Homebuyer Mortgage Program — Below-market 30-yr mortgage rate (Income-qualified first-time homebuyer)
- Highlands Council Septic Improvement Cost-Share (Preservation Area) — Highlands Council and NJDEP offer cost-share for septic upgrades in Preservation Area, which can apply when ADU triggers septic capacity expansion.
Contacts
Staff: Borough Construction Official (UCC enforcement), Land Use / Planning Board Secretary (Planning Board / zoning verification)
Utilities
- Water: Franklin Borough Water Department / private well (rural parcels) · 30d connect · $2,200
- Sewer: Franklin Borough Sewer Department (downtown core) / private septic (rural parcels) · 35d connect · $4,500
- Electric: JCP&L (Jersey Central Power & Light - First Energy) · 28d connect · $1,400 · separate meter required
- Gas: Elizabethtown Gas / propane (varies by parcel) · 35d connect · $1,800
Property values & taxes
Market rent by ADU size
| Sq ft | Rent |
|---|---|
| 400 | $1,100/mo |
| 600 | $1,400/mo |
| 800 | $1,675/mo |
| 1,000 | $1,900/mo |
Construction timeline
Realistic total: best 8mo · typical 13mo · worst 22mo
Sussex County GC pool is shallow (~85 active residential); winter construction season is 4-5 months only. Highlands Preservation Area review can extend worst-case timeline materially.
Modular pathway NJ DCA Bureau of Homeowner Protection - Modular & Manufactured Housing · inspectors are occasional with modular · 2 modular permits (last 24mo)
Rural roads serve module transport well; some Highlands Preservation Area access roads have weight limits. Crane access generally easy on Sussex County lots.
Financing
State ADU loans:
- NJHMFA First-Time Homebuyer Mortgage Program (NJHMFA)
- USDA Rural Development Single Family Housing Repair Loans (Section 504) (USDA Rural Development) up to $40,000
- NJ Highlands Council Septic Improvement cost-share (NJ Highlands Council / NJDEP)
Insurance impact
Rural insurance market in NW NJ is thinner; Highlands forest-fringe parcels may see modest wildfire premium uplift. Standard admitted-carrier coverage available.
HOA prevalence & preemption
Rural Franklin Borough is overwhelmingly fee-simple single-family on individual lots; HOA prevalence very low. NJ does NOT preempt HOA-ADU prohibitions.
Regulatory overlays (4)
- other — NJ Highlands Region (Preservation Area + Planning Area) - parts of Franklin Borough are in Preservation Area · +90d · +18% cost
Highlands Preservation Area parcels require Highlands Applicability Determination and potentially full Highlands Preservation Area Approval; can add 60-180 days. Planning Area parcels follow conformed local plan. (map) - flood-zone — Wallkill River SFHA Zone AE / X-shaded along borough's southern edge · +14d · +6% cost
Wallkill River floodplain affects southern parcels; finished-floor elevation requirements apply. (map) - historic-district — Franklin Mineral Mine / Sterling Hill Mining Museum vicinity; mining heritage industrial area · +14d · +4% cost
Mining-heritage industrial area parcels may require Borough Historic Sites Committee review; impacts limited to handful of parcels. (map) - wui-fire-zone — Borough is within NJ Forest Fire Service moderate-risk WUI given rural-forest interface · +7d · +4% cost
Defensible-space recommendations apply; not regulatory but insurance carriers may price in wildfire risk. (map)
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- NJ Uniform Construction Code (UCC) state amendments — NJ removes IRC R313 sprinkler mandate; defines NJ subcode structure.
- Franklin Borough Code Chapter 84 - Construction Codes — Franklin Borough local construction-code provisions; references Chapter 161 land-development for zoning coordination.
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: Franklin Borough Code Chapter 161 - Land Development (Article V Zoning), adopted 1996-07-23, last amended 2025-06-15
- 1985-07-02 — New Jersey Fair Housing Act (N.J.S.A. 52:27D-301 et seq.) (state-law)
Codified Mt. Laurel; established statewide fair-share housing obligation including for rural Sussex municipalities.
Effect: Franklin Borough Round 4 (2025-2035) obligation administered by NJDCA; ADU production counts toward credit. - 2004-08-10 — NJ Highlands Water Protection and Planning Act (N.J.S.A. 13:20-1 et seq.) (state-law)
Created NJ Highlands Council and imposed development restrictions on the 800,000-acre Highlands Region (Preservation Area + Planning Area) covering parts of seven counties including Sussex.
Effect: Franklin Borough has both Preservation Area and Planning Area parcels; Preservation Area triggers Highlands resource-area review for new ADUs; Planning Area follows conformed local Highlands element. - 2004-09-28 — Franklin Borough Zoning Map (filed) (city-ordinance)
Current Zoning Map of the Borough of Franklin filed in the Borough Clerk's office; defines residential, commercial, industrial, and conservation districts.
Effect: Operative zoning map referenced by Chapter 161 Article V. - 2024-04-04 — NJ A1671 / S705 - statewide ADU enabling law signed (state-law)
Required NJDCA Commissioner to publish two model ADU ordinances; municipalities must adopt one. ADU treated as ministerial use; statewide standards (300-1200 sqft, 5 ft setback, 20 ft height, max 1 parking).
Effect: Franklin Borough Chapter 161 ADU framework will be conformed to NJDCA model ordinance; Highlands Council overlay still applies in Preservation Area parcels even after conformance. - 2025-06-15 — Franklin Borough Code update (eCode360 codification 2025-06) (city-ordinance)
Most recent eCode360 codification of Franklin Borough Code including Chapter 161 Land Development.
Effect: Current operative ordinance pending NJDCA model-ordinance conformance.
Known issues (2)
- policy-pending (since 2024-04) — Until NJDCA publishes the two model ordinances and Franklin adopts one, ADU treatment relies on Chapter 161 plus statewide A1671 ministerial preemption. (source)
- overlay-burden (since 2004-08) — Highlands Preservation Area parcels face significantly longer permitting timeline (60-180 day adder) and stricter resource-area constraints; Planning Area parcels are far less impacted. (source)
New Jersey state — ADU law and programs
State financing programs
New Jersey Housing and Mortgage Finance Agency (NJHMFA), an in-but-not-of agency under the Department of Community Affairs (DCA), does not operate an ADU-specific homeowner loan or grant product as of 2026-04-26. ADU construction or rehab can be financed through NJHMFA's first-mortgage and down-payment-assistance products when the underlying primary-residence transaction qualifies: the Statewide Down Payment Assistance Program (DPA) provides up to $15,000 in DPA varying by county, with the First Generation DPA Program adding $7,000 in forgivable assistance for qualified first-generation buyers. NJHMFA's 100% Financing Program and Police and Firemen's Retirement System (PFRS) Mortgage Program are similar non-ADU-specific homeowner instruments. The federal Homeowner Assistance Fund administered by NJHMFA (NJERMA portal) provides delinquency-relief funding rather than ADU financing.
State housing programs
New Jersey's principal state-level ADU-touching program is the 2024 Mount Laurel reform (P.L.2024 c.2, the Affordable Housing Reform Act, signed 2024-03-20), which restructures the affordable-housing-obligation calculation and explicitly allows income-restricted ADUs to count toward a municipality's Round 4 Mount Laurel obligations. This is a financial incentive: a municipality that adopts an ADU-permissive ordinance and tracks income-restricted ADUs can offset its obligation calculation, reducing net new affordable-unit production demand. The Department of Community Affairs (DCA) administers the affordable-housing-obligation calculation; the Council on Affordable Housing (COAH, currently dormant) historically held that role. New Jersey does not operate a statewide pre-approved ADU plan catalog, statewide impact-fee waiver statute, or per-ADU rebate. The Aging in Place Council and DCA's Universal Design / accessibility-enhancement programs occasionally touch ADU-style 'in-law suite' projects.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Codes
- 07416
- 07439
Post Office
- 270k State Rt 23, 07416