Bolthole Index

Strafford County, New Hampshire

Zoning, building permits and septic rules in Dover, New Hampshire

Inside Dover, New Hampshire, building permits come from the city's Inspection Services office under the state building code1. Zoning is the city's own Chapter 170 ordinance, run by the Planning Department2. Septic plans need state approval from NHDES, not the county3. Strafford County issues none of these for land inside the city.

At a glance

Building permit
Required; issued by the City of Dover14
Zoning
City zoning ordinance (Chapter 170), with a published district map25
Permit decision time
Building inspector decides within 30 days at most6
Septic
State plan approval from NHDES; who inspects inside Dover is unconfirmed37
Lot size without city sewer and water
30,000 sq ft minimum for a residential structure8
Accessory dwelling unit
Limited: 300 to 950 sq ft, annual certificate of use9

Who to call

Building permits

City of Dover Inspection Services

Building, electrical, plumbing and mechanical permits and inspections inside the City of Dover

603-516-6038

269 Mast Road, Dover, NH

Online permits →

Zoning

City of Dover Planning Department

Zoning administration, site plan review and the Zoning Board of Adjustment inside the City of Dover

603-516-6008

dover-planning@dover.nh.gov

288 Central Ave., Dover, NH 03820

Online permits →

Septic permits

New Hampshire Department of Environmental Services, Land Resource Management

State approval of septic (subsurface sewage disposal) plans and construction, statewide

(603) 271-3503

29 Hazen Drive, Concord, NH 03302-0095

Online permits →

Contact details are copied from each office’s official page and were checked against it on October 24, 2026.

Off-grid gear

Going off-grid in Dover means bringing your own water and power. The kit we’d start with:

These are affiliate links — we may earn a commission, at no cost to you. As an Amazon Associate, Bolthole Index earns from qualifying purchases.

Do you need a building permit in Dover, NH?

Yes. Dover has adopted the New Hampshire State Building Code as its local building code, and construction, alteration and occupancy of buildings inside city limits are covered, including permits1. State law says the person responsible for construction must obtain a permit before starting work10.

Applications come from the owner or lessee, or an agent of either. The building inspector must approve or deny a completed application within a reasonable time, not to exceed 30 days6. Dover accepts permit applications through its online portal4.

We could not confirm whether Dover has an owner-builder exemption, what certificate of occupancy a new home needs, or the fee schedule. Ask Inspection Services before you budget.

Who issues building permits in Dover, and how do you reach them?

The City of Dover Inspection Services division issues building permits inside the city. It works from 269 Mast Road and can be reached at 603-516-6038, Monday to Friday, 8 a.m. to 4 p.m.4. Permits and licenses are applied for through the city's online portal at permits.dover.nh.gov4.

For zoning questions and site plan review, call the Planning Department at 603-516-6008 or email dover-planning@dover.nh.gov11. Its office is at 288 Central Ave., Dover, NH 0382011. Site plans can also be submitted online through the same portal11.

These offices serve land inside Dover. Land in neighboring towns uses that town's own offices, and the county's page covers the county as a whole: Strafford County.

Does Dover have zoning, and what does it mean for lots and setbacks?

Dover has its own zoning, Chapter 170 of the city code, administered by the city rather than the county2. The city is divided into residential, nonresidential, mixed-use and overlay districts, including R-40, R-20 and R-12 for housing5.

Lot size depends on the district and on utilities. In R-20, single-family neighborhoods are built on lots of not less than 20,000 square feet12. In R-12 the figure is 12,000 square feet13. Where municipal sewer and water are not provided, no residential structure may be built on a lot under 30,000 square feet in any district, and where city water exists but sewer does not, the minimum is 20,000 square feet8.

We could not confirm setbacks, lot coverage, height limits or minimum home size, which sit in the zoning dimensional table. Ask the Planning Department for the table for your district.

How do septic permits work in Dover?

New Hampshire requires state approval of plans and specifications before anyone builds a structure that discharges sewage or builds a septic system3. The New Hampshire Department of Environmental Services reviews them, and plans must be prepared by a permitted New Hampshire septic system designer7. The state's fee is $450 for each system14.

The state also requires final inspection and approval before the system is covered or used15. State law allows NHDES to delegate inspection to a city's full-time health officer or building inspector16, but we could not confirm whether Dover is one of those cities.

If Dover's public sewer is within 100 feet of a building, state law expects the building to connect to it17. Dover's own hookup rules sit in its sewer and water chapter, which we could not confirm. Ask Inspection Services whether your lot must connect.

Can you add an accessory dwelling unit, or live in an RV or tiny home, in Dover?

Dover allows accessory dwelling units (ADUs) in a limited way, where the zoning district permits one. An ADU must have at least 300 and no more than 950 square feet of living area, and a property may have one ADU9. An annual certificate of use from the zoning administrator is required, renewed by January 19. Outside the R-40 district, a second ADU may be allowed if it meets the HUD fair market rent rates for Dover9.

We could not confirm Dover's rules for living in an RV, camping on private land, or placing a tiny home or manufactured home on an individual lot. Do not assume they are allowed. State rules for recreational campgrounds do not answer the question for a private lot. Ask the Planning Department before you buy.

Building a home in Dover: the steps, in order

  1. Call the Planning Department and confirm your lot's zoning district and minimum lot size5.
  2. Ask whether public sewer and water reach the lot, because that sets the minimum lot size8.
  3. If you are dividing land, expect planning board review under the city's Land Subdivision Regulations18.
  4. If the lot will use a septic system, hire a permitted designer and file plans with NHDES for approval7.
  5. Apply for the building permit with Inspection Services through the city portal4.
  6. Request inspections as the work proceeds. We could not confirm Dover's inspection schedule, so ask Inspection Services.

What stays with Strafford County, and what to check before you buy in Dover?

Strafford County does not issue building permits or zoning for land inside Dover; the city does2. Septic approval is a state matter19.

For money and site context at the county level, Strafford County's effective property tax rate is 2%20. Only 4.8% of the county's soils rate as not limited for a conventional septic drain field, so expect a site evaluation and possibly an engineered system21. We could not confirm Dover's rules on driveways, floodplain or wetland overlays, or private wells; ask the Planning Department about overlay districts and NHDES about wells.

Watch-outs

  • We could not confirm Dover's rules for RVs, tiny homes, setbacks, minimum home size, driveway access, floodplain development or private wells; call the Planning Department at 603-516-6008 before you buy11.
  • Dover's building code may include local amendments to the state code that we could not review; ask Inspection Services1.
  • Sewer and water hookup requirements in Dover's city code apply on top of the lot-size rule, so a lot near city lines may not be allowed a septic system22.

Sources

  1. Chapter 57: Building Construction - City of Dover, NH (eCode360) (Dover), quoted and re-checked
  2. Article III: Districts and District Boundaries - City of Dover, NH (Chapter 170 Zoning) (Dover), quoted and re-checked
  3. Chapter 485-A Water Pollution and Waste Disposal, quoted and re-checked
  4. City of Dover Inspection Services (dover.nh.gov)
  5. Article III: Districts and District Boundaries - City of Dover, NH (Chapter 170 Zoning) (Dover), quoted and re-checked
  6. Chapter 57: Building Construction - City of Dover, NH (eCode360) (Dover), quoted and re-checked
  7. New Hampshire Department of Environmental Services, Land Resource Management (des.nh.gov)
  8. Article V: Dimensional Regulations - City of Dover, NH (Chapter 170 Zoning) (Dover), quoted and re-checked
  9. Article VI: Additional Regulations - City of Dover, NH (Chapter 170 Zoning) (Dover), quoted and re-checked
  10. Section 155-A:4 Permit Required, quoted and re-checked
  11. City of Dover Planning Department (dover.nh.gov)
  12. Article III: Districts and District Boundaries - City of Dover, NH (Chapter 170 Zoning) (Dover), quoted and re-checked
  13. Article III: Districts and District Boundaries - City of Dover, NH (Chapter 170 Zoning) (Dover), quoted and re-checked
  14. Section 485-A:30 Fees, quoted and re-checked
  15. Chapter 485-A Water Pollution and Waste Disposal, quoted and re-checked
  16. RSA 485-A:29 Submission and Approval of Plans and Specifications (New Hampshire statewide rule), quoted and re-checked
  17. RSA 147:8 Toilets; Drains (New Hampshire statewide rule), quoted and re-checked
  18. Table of Contents - City of Dover, NH (eCode360) (Dover), quoted and re-checked
  19. Chapter 485-A Water Pollution and Waste Disposal, quoted and re-checked
  20. Effective property tax rate: Bolthole Index county data
  21. 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
  22. Article V: Dimensional Regulations - City of Dover, NH (Chapter 170 Zoning) (Dover), quoted and re-checked

Written October 24, 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.

Answers from the rulebook for Dover

Dover’s own rules

  • Building code adoptedAdopted

    Construction, alteration and occupancy of buildings and structures inside Dover city limits.

    • The city adopts the New Hampshire State Building Code under RSA 155-A as its local Building Code.
    • Section 57-2 states the chapter may contain deletions, modifications and amendments to the building code; any local amendments were not verified in the text reviewed.
    “there is hereby adopted by the city of dover, new hampshire, for the purpose of establishing rules and regulations for the construction, alteration, removal, demolition, equipment, use, occupancy, location and maintenance of buildings and structures, including permits, that certain building code known as the "state building code," pursuant to rsa 155-a, which shall be known as the "building code."”
  • Local zoningPresent (with conditions)

    Land inside Dover city limits: the city's own Zoning Ordinance, Chapter 170 of the Code of the City of Dover, administered by the city.

    • Zoning is administered by the city zoning administrator and planning and community development department; the Chapter 170 article text reviewed here does not name a separate county zoning role inside the city.
    • Use, dimensional and occupancy rules are set by Chapter 170 and its attachments (zoning map, use tables, dimensional table), not by county zoning.
    “the city of dover is hereby divided into the following districts:”
  • Zoning districtsPublished (with conditions)

    Zoning districts and the zoning map for land inside Dover city limits.

    • Districts: residential R-40, R-20, R-12, RM-SU, RM-U and HR; nonresidential C, CM and IT; mixed-use G, H, LBW, O, CBD and CWD; overriding districts including CD, URD, RRD, GWP, HWD, RCM, SRD, TDR, TEL and WPD.
    • The zoning map and CBD regulating plan are adopted by reference; the map is dated September 11, 2019 per the code text.
    “the city of dover is hereby divided into the following districts:”
  • Minimum lot sizeSpecified

    Residential structures on lots inside Dover city limits where municipal sewer and water facilities are not provided (applies in every district, overriding the district lot figures where stricter).

    • Where municipal water is available and sewer is not, the minimum is 20,000 square feet.
    • The minimum may not be more permissive than the New Hampshire Department of Environmental Services water division requirements or other requirements in Chapter 170.
    • The section does not substitute for mandatory hookups under other chapters of the city code.

    minimum lot area, no municipal sewer or water: >= 30000 sq ft (where municipal sewer and water facilities are not provided) · minimum lot area, municipal water but no sewer: >= 20000 sq ft (where municipal water is available and sewer is not)

    “in instances where municipal sewer and water facilities are not provided, no residential structure shall be built on a lot with less than 30,000 square feet in area. where municipal water is available and sewer is not, the minimum lot size shall be 20,000 square feet in area.”
    2 more reviewed findings on this topic
  • Accessory dwellingsLimited

    Accessory dwelling units on residential property inside Dover city limits, where the zoning district permits an ADU.

    • Applies only where an ADU is permitted; the residential districts where ADUs are permitted were not identified in the captured text.
    • Maximum one ADU per property; an ADU is not permitted on a property where more than one dwelling unit currently exists.
    • Outside the R-40 district, more than one ADU may be allowed if the second unit meets the HUD fair market rent rates for Dover published by the New Hampshire Housing Finance Authority.
    • Living area must be at least 300 square feet and no more than 950 square feet.
    • Alterations must not make the house look like a duplex or multifamily structure.
    • An annual certificate of use from the zoning administrator is required, renewed by January 1; fees are set in the city fee schedule.
    • Owner-occupancy and parking conditions were not captured within the research budget.

    ADU area minimum: >= 300 sq ft · ADU area maximum: <= 950 sq ft · ADU count per property: <= 1 units (other residential districts may allow a second ADU meeting HUD FMR rates; R-40 excluded)

    “an adu shall have an area of no less than 300 square feet and no greater than 950 square feet.”
  • Mandatory utility hookupConditional

    New residential structures on lots inside Dover city limits, depending on whether municipal sewer and water facilities are provided to the lot.

    • The city's Zoning Article V ties the minimum lot size to whether municipal sewer and water are provided (see minimum_lot_size claims).
    • Section 170-13 states the lot-size rule does not replace mandatory hookups required by other chapters of the city code; those hookup terms (Chapter 121 Sewers and Water) were not opened and are not verified here.
    • The distance from a main that triggers a hookup requirement was not established.
    “furthermore, the above requirement shall not be substituted for mandatory hookups required by other chapters of the code of the city of dover.”
  • Subdividing landRegulated (with conditions)

    Division of land into lots inside Dover city limits.

    • Subdivision is governed by the city's Chapter 157 Land Subdivision Regulations under the Planning Board, listed in the eCode360 table of contents.
    • Site review is governed by Chapter 153; open-space subdivisions are governed by Article VII and the Open Space Subdivisions section.
    • Chapter 157 text was not opened; approval steps were not verified.
    “chapter 157 land subdivision regulations (§ 157-1 &ndash; § 157-60)”
  • Permit processPartial

    Building permit applications for work inside Dover city limits under Chapter 57.

    • Application is made by the owner or lessee of the building or structure, or an agent of either.
    • The building inspector must approve or deny a completed application within a reasonable period not to exceed 30 days.
    • Work under an issued permit must commence within the time set by the state building code and state fire code under RSA 155-A.
    • Application form, required plans and inspection steps were not captured.

    decision period: <= 30 days (reasonable period, not to exceed 30 days)

    “upon the filing of a completed application, the building inspector shall approve or deny the application within a reasonable period of time, not to exceed 30 days.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Dover or Strafford County directly.

  • Owner-builder exemption — Owner-builder permit exemption inside Dover city limits.
  • Inspections — Inspections of new construction inside Dover city limits.
  • Certificate of occupancy — Occupancy certificate for new homes inside Dover city limits.
  • Minimum dwelling size — Minimum floor area of a single-family dwelling in the R-20 and R-12 districts inside Dover city limits.
  • Setbacks — Front, side and rear setbacks for single-family dwellings in the R-40, R-20 and R-12 districts inside Dover city limits.
16 more unanswered
  • Lot coverage
  • Building height
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain
  • Short-term rentals
  • Permit fees

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Dover publishes no rule on the point, not that none exists. Strafford County’s page lists the county offices to call.

← All of Strafford County: county rules, score and offices