Zoning, building permits and septic rules in Town of Duncan, Arizona

Town of Duncan’s own rules

• Building permitRequired

  Renovation, demolition or removal of commercial buildings inside Duncan town limits (asbestos-related permit clause).

  • Permit issuance is contingent on proof of asbestos-handling compliance with federal and state law.
  • Does not establish the rule for new residential construction; see the unknown residential claim.

  “wishing to renovate, demolish or remove a commercial building in the town of duncan must first obtain a building permit from the town hall.”

• Building code adoptedAdopted

  Building construction inside Duncan town limits under Chapter 7 Building (Revised 6/06).

  • Adopted edition is stated as the 2006 International Building Code in the posted Revised 6/06 chapter; the 2025 full code was not checked for a later edition.
  • Chapter 7 also adopts the uniform plumbing code, national electrical code, uniform mechanical code, uniform solar energy code and uniform sound transmission control code by 'current edition' language.

  “those certain codes entitled the 2006 international building code are hereby adopted and made a part of this chapter the same as though said codes were specifically set forth in full herein”

• Local zoningPresent (with conditions)

  All land inside Duncan town limits; the town adopts and administers its own zoning chapter (Chapter 15, Zoning Regulations).

  • Building work for which a building permit is issued must also conform to the town zoning ordinance.
  • Zoning chapter text was read from the 2025 full code PDF; the standalone 2021 Chapter 15 PDF timed out and was not read.

  “whenever a building permit is issued and a building inspection performed, such building must conform to the provisions of the zoning ordinance of duncan in addition to the provisions of this chapter.”

• Minimum lot sizeDistrict specific (with conditions)

  Lots in the Duncan Residential Zone (DR) inside Duncan town limits; the agricultural or rural district was not identified.

  • Minimum lot size depends on water and sewer service and on whether the lot uses a private well or septic tank.
  • Lot size in the text is measured excluding easements.

  minimum lot size, base DR lot: >= 5000 square feet (default where other service conditions below do not apply) · minimum lot size, lot served by both community water and sewer: >= 10000 square feet (where the lot is to be served by both a community water and sewer system) · minimum lot size, private well with community water system: >= 21780 square feet (one half acre where a private well is used in conjunction with a community water system) · minimum lot size, private well and septic tank: >= 43560 square feet (one acre where a private well and septic tank are to be used)

  “the minimum lot size shall be five thousand (5,000) square feet. where a private well and septic tank are to be used, the minimum lot size shall be one acre (43,560 square feet), excluding easements.”

• SetbacksDistrict specific (with conditions)

  Lots in the Duncan Residential Zone (DR) inside Duncan town limits.

  • Front setback may equal the average setback of dwellings on adjoining or adjacent properties.
  • Babbitt Heights subdivision has a 10-foot front and side setback instead.

  minimum front yard setback: 15 feet (may be the average setback of dwellings on adjoining or adjacent properties; 10 feet in Babbitt Heights subdivision) · minimum side yard setback: 5 feet (10 feet in Babbitt Heights subdivision)

  “the minimum front yard setback shall be fifteen feet (15’); except that the setback may be the average setback of dwellings on adjoining or adjacent pr”

• Accessory dwellingsLimited

  Second dwelling units on a lot in the Duncan Residential Zone (DR) inside Duncan town limits.

  • Only one dwelling per lot is allowed except in an approved multifamily development; this effectively bars a second dwelling unit (including an accessory unit) on a DR lot unless approved as multifamily.
  • The rule does not use the term accessory dwelling; the DR permitted-use list was not read.

  “there shall be no more than one dwelling per lot except in an approved multifamily development.”

• Off-grid sanitationLimited

  Off-grid (septic or other local) sewage disposal inside Duncan town limits.

  • Prohibited for parcels within 100 feet of a town sewer; existing tanks are allowed to remain.
  • Parcels not adjacent to or within 100 feet of a collector or other town sewer are exempt (section 12-3-1).
  • Town council may approve private systems when the town cannot serve (section 12-3-4).

  “the use of septic or other local means of sewage disposal, within the town, except where such tanks presently exist, is hereby declared to be a public nuisance and is declared to be abated.”

• Mandatory utility hookupSewer (with conditions)

  Inhabited buildings inside Duncan town limits (new homes).

  • Connection is required unless the town is unable to provide sewer.
  • A permit and the fees required by the town must be obtained before a private sewer line connects to the town system (section 12-2-2).
  • Water connection requirements (Chapter 16) were not confirmed and are not covered by this claim.

  “all buildings, except those exempt in section 12-3-1, within the town inhabited or used by human beings are to be connected with the sewage system of the town of duncan, unless the town is unable to provide sewer.”

• Subdividing landRegulated (with conditions)

  Subdivision of land inside Duncan town limits (Chapter 15, article 15-11).

  • Plat submittal requirements include drainage, soil percolation test results and utility lines.
  • Article 15-11 text was read only in part.

  subdivision plat processing fee: 25 USD (or two dollars per lot, whichever is greater)

  “processing fee of twenty-five dollars ($25) or two dollars ($2) per lot, whichever is greater.”

• Permit feesVariable (with conditions)

  Building permit fees inside Duncan town limits.

  • Fee amounts are set by council resolution, not in the code text; the town's Fee Schedule 5.2026 PDF was seen in search results but not opened, so amounts are not stated here.

  “building permit fees shall be set from time to time by resolution of the council.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Town of Duncan or Greenlee County directly.

• Owner-builder exemption — Owner-builder permit exemption inside Duncan town limits.
• Certificate of occupancy — Certificate of occupancy for buildings inside Duncan town limits.
• Minimum dwelling size — Minimum dwelling floor area inside Duncan town limits.
• Lot coverage — Lot coverage limits inside Duncan town limits.
• Building height — Maximum building height inside Duncan town limits.

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.