The Town of Johnston, Rhode Island adopts its own zoning ordinance, Chapter 340 of the town code1. Building permits follow the Rhode Island State Building Code and are issued by the town, not by Providence County, which has no building authority2. Septic permits for homes without public sewer come from the state Department of Environmental Management3.
At a glance
- Building permit
- Required under the Rhode Island State Building Code; the town issues it4
- Zoning
- Town zoning ordinance, Chapter 340, with named districts such as R-40 and R-2015
- Septic
- State permit from RI DEM where no public sewer is available; town rules also apply67
- RV living
- Limited: occupying a trailer on a lot is restricted; one unoccupied trailer may be kept in a garage or rear yard8
- Accessory dwelling
- One per lot allowed by state law when statutory conditions are met9
- Owner-builder
- Owner-occupants may do their own work without contractor registration, but permits and inspections still apply10
Who to call
Building permits
Town of Johnston Building Division
Building, plumbing, mechanical, electrical, demolition, sign and solar permits for the Town of Johnston; permitting is handled online
Septic permits
Rhode Island DEM Office of Water Resources – OWTS Program
Statewide septic (OWTS) permitting, design review and inspection, including in Johnston
235 Promenade Street, Providence, RI 02908
Contact details are copied from each office’s official page and were checked against it on October 14, 2026.
Off-grid gear
Going off-grid in Town of Johnston means bringing your own water and power. The kit we’d start with:
- Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
- Power Bluetti Solar generators and home battery backup for living off the grid.
- Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
- Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.
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Does Johnston, RI have zoning, and what does it mean for RVs and lot size?
Yes. The Town of Johnston adopts its own zoning ordinance, Chapter 340 of the town code, and divides the town into zoning districts1. The districts include R-40 and R-20, and the zoning map is filed with the town clerk5.
Minimum lot sizes, setbacks and which uses each district allows sit in the use and dimensional tables at the end of Chapter 3401. We could not confirm those figures, so ask the town's Planning and Zoning Division which district a parcel is in before you buy.
On RVs, Johnston's trailer chapter says no one may park or occupy a trailer on a lot, whether or not a dwelling stands on it, except one unoccupied trailer kept in a garage or rear yard. Violations are a misdemeanor with a fine of $50 to $100 per day8. Living in an RV on a Johnston lot is therefore not a practical plan.
Do you need a building permit in Johnston, RI, and who issues it?
Yes. Rhode Island requires a permit for construction, enlargement, alteration, removal and demolition under the State Building Code, and the one- and two-family work a homeowner does is governed by the state's One and Two-Family Dwelling Code4. Counties in Rhode Island cannot require building permits, so the town is the office to deal with2.
In Johnston the Building Division issues building, plumbing, mechanical, electrical, demolition and solar permits, and the town says permitting is conducted online while you can still stop in the offices to discuss a project11. Work under a permit must be inspected, and a new building needs a certificate of use and occupancy before it is used12.
An owner who lives in and builds their own single-family home may be exempt from contractor registration, but permits and inspections still apply10. We could not confirm Johnston's fee schedule; ask the Building Division.
How do septic permits work in Johnston, RI?
Where no public sewer is available, a house in Johnston must connect to an on-site wastewater system that meets both town and Rhode Island DEM requirements7. DEM's OWTS Program is the permitting authority for septic systems in the state3, and a permit is required for a new structure that will use one6. A licensed designer must witness the installation13.
Where a public sewer abuts the street or easement and the town's director finds it accessible with adequate capacity, an occupied building must connect to it instead14. Contact the15 at (401) 222-3961 for septic questions.
Building permits and zoning are the town's job; septic stays with the state.
Can you live in an RV, tiny home or accessory dwelling in Johnston, RI?
RVs: Johnston limits trailer occupancy on lots, as described above8. Statewide, extended RV stays are allowed in recreational vehicle parks and campgrounds, not on a private lot16.
Accessory dwellings: Rhode Island allows one accessory dwelling unit per lot in residential zoning districts when the statutory conditions are met9.
Manufactured homes: state law allows manufactured homes as single-family homes on lots zoned for single-family use17.
We could not confirm how Johnston's use table treats tiny homes or minimum dwelling size; ask the Planning and Zoning Division.
What stays with the state and county when you build in Johnston, RI?
Septic permits come from RI DEM, not the town3. A driveway onto a state highway needs a Rhode Island DOT access permit18. Projects that may alter freshwater wetlands, buffers or floodplains need DEM approval19.
Providence County itself has no zoning authority20. The county page at Providence County covers the wider area.
Providence County's effective property tax rate is 1.4% and the median bill is $4,661 a year2122.
Watch-outs
- We could not confirm Johnston's minimum lot sizes, setbacks, fees or tiny-home rules; the Planning and Zoning Division and the Building Division can answer them11.
- Soil ratings are poor for conventional drain fields in Providence County, so expect a site evaluation and possibly an engineered system23.
- Johnston's town code ties septic to both town and DEM rules, so check Chapter 332 on wastewater management with the town before designing a system7.
Sources
- Johnston Code Ch. 340 Zoning, Article III: Zoning Districts and Map; Use Table (Town of Johnston), quoted and re-checked
- R.I. Gen. Laws § 23-27.3-100.1 — Short title — Applicability (Rhode Island statewide rule), quoted and re-checked
- Obtaining a Permit for a New Home’s Septic System (Rhode Island statewide rule), quoted and re-checked
- R.I. Gen. Laws § 23-27.3-113.1 — When permit is required (Rhode Island statewide rule), quoted and re-checked
- Johnston Code Ch. 340 Zoning, Article III: Zoning Districts and Map; Use Table (Town of Johnston), quoted and re-checked
- Rules Establishing Minimum Standards Relating to Location, Design, Construction and Maintenance of Onsite Wastewater Treatment Systems (Rhode Island statewide rule), quoted and re-checked
- Johnston Code Ch. 279 Sewers (Town of Johnston), quoted and re-checked
- Johnston Code Ch. 319 Trailers and Mobile Homes (Town of Johnston), quoted and re-checked
- R.I. Gen. Laws § 45-24-73. Design standards required for accessory dwelling units (Rhode Island statewide rule), quoted and re-checked
- RI Contractors' Registration and Licensing Board - FAQs (2026 county census)
- Town of Johnston Building Division (johnstonri.gov)
- R.I. Gen. Laws § 23-27.3-120.1 — New buildings (Rhode Island statewide rule), quoted and re-checked
- Rules Establishing Minimum Standards Relating to Location, Design, Construction and Maintenance of Onsite Wastewater Treatment Systems (Rhode Island statewide rule), quoted and re-checked
- Johnston Code Ch. 279 Sewers (Town of Johnston), quoted and re-checked
- Rhode Island DEM Office of Water Resources – OWTS Program (dem.ri.gov)
- R.I. Gen. Laws § 32-7-7 — Definitions (Rhode Island statewide rule), quoted and re-checked
- R.I. Gen. Laws § 45-24-37. General provisions — Permitted uses (Rhode Island statewide rule), quoted and re-checked
- Physical Alteration Permit Application Manual (Rhode Island statewide rule), quoted and re-checked
- Rules and Regulations Governing the Administration and Enforcement of the Freshwater Wetlands Act (Rhode Island statewide rule), quoted and re-checked
- R.I. Gen. Laws § 45-24-50 — Adoption — Power of council to adopt (Rhode Island statewide rule), quoted and re-checked
- Effective property tax rate: Bolthole Index county data
- Median property tax bill: Bolthole Index county data
- Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
Written October 14, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.