ADU Pass
Hopkinton
ADU Pass helps homeowners in Hopkinton, Washington County, Rhode Island navigate the permit paperwork for building an accessory dwelling unit. This area covers 1 ZIP code.
Map
ADU details
ADU legality: allowed
Rhode Island preempts most local ADU restrictions. Hopkinton permits ADUs by right in single-family zones per its zoning ordinance.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 150 | $2,600 | $39,600 | $42,200 |
| 600 | 600 | $2,600 | $158,400 | $161,000 |
| midpoint | 675 | $2,600 | $178,200 | $180,800 |
| maximum | 1,200 | $2,600 | $316,800 | $319,400 |
Fee breakdown
Permitting process
- Confirm Appendix A Zoning district (~1d)
Verify parcel is in an R-zone where single- and two-family uses are established; ADUs follow state floor in any district allowing the principal use (RIGL §45-24-37(j)). Hopkinton's mostly RFR-80 (Rural Farming Residential, 80,000 sqft min lot) and R-3A make most lots eligible by lot size. - Septic / OWTS pre-check (most parcels) (~30d)
Hopkinton has no centralized municipal sewer — private OWTS dominates. Apply for or amend the RIDEM ISDS permit through the Town's Building & Zoning office at the Charles Niles Complex (395 Woodville Road) before final building permit issuance. Existing systems may need expansion to support the added bedroom. - Apply via permits.ri.gov statewide e-permitting (~1d)
Hopkinton accepts building permits through the statewide RI e-permitting portal at permits.ri.gov; paper backups handled at 395 Woodville Road, Hopkinton RI 02833 (7:30 a.m. - 3:30 p.m. M-F). - Plan review by Building Official Anthony Santilli (~18d)
Building, MEP, and zoning review against IRC 2018 + RI amendments (RI removed the R313 sprinkler mandate so detached ADUs do not need NFPA 13D). Anthony Santilli reachable at 401-377-7771. - Planning Department coordination if site changes (~5d)
Town Planner Talia Jalette (482 Main St., Thayer House 2nd floor, 401-377-7770) signs off if the ADU triggers a site-plan review (rare for in-envelope conversions; common for new detached structures). - Pay statewide-formula fees (~1d)
Fee assessed on declared construction valuation per 510-RICR-00-00-21; payable through permits.ri.gov. - Construction inspections
Footing, foundation, framing, MEP rough, insulation, final — scheduled directly with Building Official's office at 401-377-7771. - Certificate of Occupancy (~3d)
Issued by Building Official Anthony Santilli at final pass; required before tenant occupancy under RIGL Title 23.
Hopkinton's Building & Zoning office runs a small queue (rural town, ~8,400 residents); plan review by Building Official Anthony Santilli is typically the bottleneck rather than counter intake. Lots without municipal sewer (the dominant case in Hopkinton) add a RIDEM ISDS / OWTS septic-permit cycle that can extend wall-clock to 90+ days.
Viability (permitted uses)
- Long-term rental: yes Long-term rental of ADU explicitly permitted; Rhode Island owner-occupancy preemption (where applicable) makes ADU eligible for full landlord-tenant treatment.
- Short-term rental: with-restrictions STR rules vary by city. Hopkinton regulates STRs separately from ADU permitting; check local STR ordinance and HOA covenants.
- Office rental: with-restrictions Detached office rental requires home occupation permit or rezoning.
- Home office: yes Home occupation permitted with restrictions on signage and customer traffic.
- Studio / workshop: yes Personal artist studio is a permitted accessory use.
- Agriculture: with-restrictions Limited urban agriculture permitted in residential zones; livestock varies by district.
- Relative support: yes Family-occupancy ADU explicitly permitted in single-family zones.
Contacts
Staff: Anthony Santilli (Building Official), Talia Jalette (Town Planner), Michael Spellman (Senior Planning Clerk)
Utilities
- Water: Hopkinton Water Utility · 21d connect · $4,500
- Sewer: Hopkinton Sewer / Wastewater · 21d connect · $5,500
- Electric: Hopkinton Electric Utility · 14d connect · $1,800
- Gas: Hopkinton Gas Utility · 21d connect · $1,500
Property values & taxes
Construction timeline
Realistic total: best 7mo · typical 11mo · worst 17mo
Financing
State ADU loans:
Insurance impact
HOA prevalence & preemption
R.I.G.L. § 45-24-73 explicitly voids homeowners' association, condominium association, or similar private-covenant restrictions on ADUs when those restrictions conflict with the statute's ADU minimums. The preemption is framed as a public-policy void, meaning the offending covenant is unenforceable rather than simply regulated. Pre-existing ADU-friendly covenants remain valid (the statute only void conflicting restrictions). Applies to all common-interest communities governed by the Rhode Island Condominium Act (R.I.G.L. Title 34, Chapter 36) and Rhode Island Condominium Ownership Act (Title 34, Chapter 36.1), as well as HOAs in planned-community subdivisions.
Regulatory overlays (2)
- flood-zone
Hopkinton has FEMA Special Flood Hazard Areas; elevation certificates and flood-resistant construction required for SFHA parcels. - historic-district
Hopkinton historic districts trigger Architectural Review Board / Historic Preservation Commission review for ADUs in historic boundaries.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
Legal history (timeline)
Current ordinance: Town of Hopkinton Code of Ordinances — Appendix A Zoning (district use regulations) read with RIGL §45-24-37(j), adopted 2024-06-25, last amended 2025-02-19
- 2024-06-25 — RI H 7062 / S 2998 effective — RIGL §45-24-37(j) by-right ADU mandate (state-statute)
Rhode Island statewide enabling statute making ADUs by-right on owner-occupied 1-3 family lots took effect statewide; preempted any conflicting Hopkinton zoning provisions.
Effect: Hopkinton's Appendix A Zoning treatment of accessory dwellings is read against the §45-24-73 statewide-consistency floor; restrictions tighter than the statute are unenforceable. - 2025-02-19 — Hopkinton Town Council conforming zoning amendments review (city-ordinance)
Hopkinton Planning Board / Town Council process to align Appendix A Zoning with the 2024 RI statewide ADU framework; small rural town with limited prior ADU activity meant amendments were largely cross-references to state minimums rather than new local standards.
Effect: Hopkinton applies the statewide 900 sqft (1-bedroom) / 1,200 sqft (2-bedroom) caps at 60% of primary dwelling, with the statewide 30-day minimum rental period. Owner-occupancy of either unit required by state floor.
Rhode Island state — ADU law and programs
State ADU law
Rhode Island enacted statewide ADU preemption in 2024 through H 7062 (chief sponsor Rep. June Speakman and colleagues; co-sponsored in the Senate as S 2710), which amended the Zoning Enabling Act (Title 45, Chapter 24). Municipalities must permit ADUs by-right on any lot containing a single-family dwelling, subject only to uniform minimum standards set by the statute. One of the most ADU-friendly state statutes in the country as of 2025.
- R.I.G.L. § 45-24-73 — Design standards required for accessory dwelling units; Consistent statewide treatment of accessory dwelling units required — Core ADU standards added by H 7062 (2024). Requires municipalities to permit ADUs by-right. Caps 1-bedroom and studio ADUs at 900 sqft or 60% of the principal dwelling's floor area, whichever is less. Caps 2-bedroom ADUs at 1,200 sqft or 60%, whichever is less. Prohibits owner-occupancy requirements. Caps additional parking at 1 off-street space per bedroom. Prohibits ADU-specific impact fees. Voids HOA, condominium, and similar private-covenant restrictions that conflict with the statute as against public policy.
- H 7062 (2024 RI General Assembly) — An Act Relating to Housing — Accessory Dwelling Units — The enacting bill. Also cited by municipalities adopting conforming ordinances (Providence 2024 Chapter 3584, East Providence 2024 ADU Ordinance, South Kingstown 2024-07-12 regulations).
State HOA preemption
R.I.G.L. § 45-24-73 explicitly voids homeowners' association, condominium association, or similar private-covenant restrictions on ADUs when those restrictions conflict with the statute's ADU minimums. The preemption is framed as a public-policy void, meaning the offending covenant is unenforceable rather than simply regulated. Pre-existing ADU-friendly covenants remain valid (the statute only void conflicting restrictions). Applies to all common-interest communities governed by the Rhode Island Condominium Act (R.I.G.L. Title 34, Chapter 36) and Rhode Island Condominium Ownership Act (Title 34, Chapter 36.1), as well as HOAs in planned-community subdivisions.
- R.I.G.L. § 45-24-73 (HOA preemption clause added by H 7062 (2024)) — Provides that private covenant restrictions imposed by condominium associations, homeowners' associations, or similar residential property governing bodies that conflict with the ADU provisions are void as against public policy. Drafted broadly — covers declarations, bylaws, rules and regulations, and recorded covenants.
State financing programs
RIHousing, the state's housing finance agency, operates an ADU financing program built around the FHA 203(k) loan product. Covers attached and interior ADUs for both purchase and refinance. Detached ADUs are NOT eligible. Requires mandatory homebuyer education, use of an FHA-approved 203(k) consultant, and a RI licensed and insured contractor. No state-specific grant program for ADUs is in effect as of 2026-04-21; the federal 203(k) rails are the production vehicle.
State housing programs
Rhode Island does not currently operate a single statewide pre-approved-ADU-plan catalog (as California's CalHFA and Washington's Commerce plan libraries). Implementation of the 2024 ADU law is happening municipality-by-municipality, with the Executive Office of Housing (EOH) coordinating technical assistance. Providence published a citywide ADU Guide (February 2025) as the leading model; East Providence adopted a conforming ordinance in 2024; South Kingstown published regulations in 2024. RIHousing runs the ADU financing side (see stateFinancing).
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 Code
- 02833
Post Office
- 482 Main St, 02833