Bolthole Index

Charleston County, South Carolina

Building permits, zoning and septic rules in the Town of Sullivan's Island, South Carolina

Building in the Town of Sullivan's Island, South Carolina requires a written permit from the Town's Building Inspector first1. The Town adopts its own zoning ordinance2, so Charleston County's zoning does not govern town lots. Septic tanks are prohibited inside town limits3, and buildings connect to the Town's public sewer4.

At a glance

Building permit
Required; written permit from the Town Building Inspector before any construction, alteration or land preparation1
Zoning
The Town publishes its own zoning ordinance (Appendix A of its code)2
Septic
Septic tanks are prohibited in the town; buildings connect to Town sewer34
Flood permit
A building/development permit is required before any development activity under the Town flood chapter5
Building codes
Town adopts the South Carolina building codes by reference, with Town amendments6
Permit fees
Set by the current Town Council resolution7
RV, tiny home, owner-builder
Not confirmed; ask the Town planning office8

Who to call

Building permits

Town of Sullivan's Island Building, Planning & Zoning Department (Building Official)

Building permits, plan review and inspections inside Sullivan's Island town limits

843-883-5732

2056 Middle Street

Zoning

Town of Sullivan's Island Planning & Zoning

Zoning questions, zoning ordinance and floodplain information inside Sullivan's Island town limits

843-883-5752

2056 Middle Street

Septic permits

South Carolina Department of Environmental Services (SCDES)

State septic and private well permitting for land outside public sewer; relevant to Sullivan's Island only for questions the Town refers to the state

(803) 898-3432

info@des.sc.gov

2600 Bull St., Columbia, SC 29201

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 Town of Sullivan's Island means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Sullivan's Island, SC?

Yes. Inside the Town of Sullivan's Island, a written permit from the Building Inspector is required before anyone erects, constructs, improves, alters or repairs a structure, or prepares land for building1. No permit issues unless the property meets the Town's Chapter 155 requirements1.

The Town adopts the South Carolina building, plumbing, mechanical, fuel gas, fire and residential codes by reference, subject to Town amendments6. Fees are whatever the current Town Council resolution sets, so ask the Building Official for today's schedule7.

Who issues building permits in Sullivan's Island, and how do you reach them?

The Town issues its own building permits. Applications go in writing to the Building Inspector or a designated representative at Town Hall on approved forms, with plans and specifications9. The Building, Planning & Zoning Department works from Town Hall at 2056 Middle Street10. Reach the Building Official at 843-883-573210 or the planning and zoning director's line at 843-883-57528.

If any part of the property lies seaward of the state's 40-year setback line, the plans must show the prescribed South Carolina Coastal Council lines and written approval from that council where required9. Charleston County Building Inspection Services handles building permits only for unincorporated land, not inside the town.

Does Sullivan's Island have zoning?

Yes. The Town of Sullivan's Island publishes its own zoning ordinance as Appendix A of its code2. Charleston County states that its Zoning and Land Development Regulations Ordinance only applies to unincorporated properties11, so county district rules, accessory dwelling limits and the county's RV rule do not apply to a lot inside town limits.

We could not confirm the Town's rules on RVs, tiny homes, manufactured homes, accessory dwellings, minimum lot or house size, setbacks, lot coverage or height. Ask the Town's planning and zoning office, and look up the lot's zoning district before making an offer.

How do septic permits work in Sullivan's Island?

They mostly do not, because the Town code says no person shall install, maintain or use a septic tank in the town3. Houses and other occupied buildings must connect to the Town's public sewer at the owner's expense, and sewer service must be contracted before connection4.

The Town need not extend sewer to an undeveloped lot without an adjacent sewer line; an extension takes an agreement with the Town, a payment agreement, Town approval of specifications and final installation4. Before buying a vacant lot, ask the Town whether a sewer line already reaches it. We could not confirm any Town rule on private wells; the state requires a Notice of Intent for residential wells12.

Can you live in an RV or tiny home in Sullivan's Island?

We could not confirm the answer. The detailed zoning use provisions for RV living, temporary camping and tiny homes were not available to us, so ask the Town's planning and zoning office at 843-883-5752 before planning on either8.

Charleston County's rule that RVs cannot be used for living, sleeping or housekeeping on residential property applies to unincorporated Charleston County and does not supersede municipal regulations13. It is not the Sullivan's Island rule.

Building a home in Sullivan's Island: the steps, in order

  1. Confirm the lot's zoning district and dimensional limits with the Town's planning and zoning office28.
  2. Confirm flood status; a building/development permit is required under the Town flood chapter before development begins5.
  3. Confirm sewer access, since septic is not an option34.
  4. Apply in writing to the Building Inspector at Town Hall with plans and specifications9.
  5. Build to the adopted codes6.
  6. Before a certificate of occupancy in flood-regulated development, provide the as-built elevation certificate and any other required flood certificates, and correct deficiencies14.

If you plan to act as your own builder, South Carolina has a statewide owner-builder exemption with conditions15; we could not confirm a Town-specific rule, so ask the Building Official.

What stays with Charleston County, and what should you check before you buy?

Land outside the town limits falls under Charleston County's rules; see the Charleston County page. Inside the town, building permits, zoning and sewer come from the Town, not the county124.

Statewide rules still apply, including state septic and well permitting through the South Carolina Department of Environmental Services16 and a state driveway permit for entrances onto primary state highways17. A typical home in Charleston County is valued at about $619,61418, and the county's effective property tax rate is about 0.4%19. Ask the Town for subdivision rules if you plan to divide a lot20.

Watch-outs

  • Zoning district rules for RVs, tiny homes, accessory dwellings, lot size, setbacks and height were not confirmed, so ask the Town's planning and zoning office before you buy8.
  • Septic tanks are prohibited in town limits, so a lot without a sewer line nearby can cost extra to serve34.
  • Flood-regulated construction needs a development permit first and elevation certificates before occupancy514.

Sources

  1. § 150.35 Required (Town of Sullivan's Island), quoted and re-checked
  2. Appendix A: Zoning (Town of Sullivan's Island), quoted and re-checked
  3. § 51.002 Septic Tank Prohibited (Town of Sullivan's Island), quoted and re-checked
  4. § 51.006 Toilet Facilities Required in Buildings; Connection with Public Sewer Required (Town of Sullivan's Island), quoted and re-checked
  5. § 153.08 Establishment of Building/Development Permit (Town of Sullivan's Island), quoted and re-checked
  6. § 150.15 Building, Plumbing and Electrical Codes Adopted (Town of Sullivan's Island), quoted and re-checked
  7. § 150.39 Fee for Building and Electrical Permits (Town of Sullivan's Island), quoted and re-checked
  8. Town of Sullivan's Island Planning & Zoning (sullivansisland.sc.gov)
  9. § 150.36 Application (Town of Sullivan's Island), quoted and re-checked
  10. Town of Sullivan's Island Building, Planning & Zoning Department (Building Official) (sullivansisland.sc.gov)
  11. Zoning & Planning Department, quoted and re-checked
  12. Private Drinking Water Wells (South Carolina statewide rule), quoted and re-checked
  13. Zoning Code Enforcement: Zoning & Planning Department, quoted and re-checked
  14. codelibrary.amlegal.com (Town of Sullivan's Island), quoted and re-checked
  15. South Carolina Code Title 40, Chapter 59 — Residential Home Builders (South Carolina statewide rule), quoted and re-checked
  16. Septic Tanks - Residential, Single Home Builder (South Carolina statewide rule), quoted and re-checked
  17. scstatehouse.gov (South Carolina statewide rule), quoted and re-checked
  18. Typical home value (Zillow): Bolthole Index county data
  19. Effective property tax rate: Bolthole Index county data
  20. § 153.42 Standards for Subdivision Proposals (Town of Sullivan's Island), 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 Town of Sullivan's Island

Town of Sullivan's Island’s own rules

  • Building permitRequired

    Erection, construction, improvement, alteration, repair, and preparatory alteration of land inside Sullivan's Island town limits.

    • A written permit from the Building Inspector is required first.
    • No permit issues unless the property meets Chapter 155 requirements.
    “without first having obtained from the Building Inspector a written permit”
  • Building code adoptedAdopted (with conditions)

    Buildings within the corporate limits of Sullivan's Island town.

    • Adopted codes are subject to portions conflicting with, deleted, modified, or amended by Town ordinances.
    • The listed codes include 2018 South Carolina Building, Plumbing, Mechanical, Fuel Gas, Fire, and Residential Codes; 2018 International Property Maintenance Code; 2017 National Electric Code; and 2009 International Energy Code.
    “The following codes are hereby adopted by reference as though they were copied herein fully:”
  • Certificate of occupancyLimited

    Flood-regulated development inside Sullivan's Island town limits.

    • Before issuance, required as-built elevation, flood-proofing, design, and breakaway-wall certificates must be provided where applicable.
    • Deficiencies must be corrected before occupancy.
    “At the end of construction and prior to issuance of a certificate of occupancy an as-built elevation certificate”
  • Local zoningPresent (with conditions)

    Land inside Sullivan's Island town limits.

    • The code publishes Appendix A as the Town's zoning ordinance.
    “ORDINANCE TO AMEND CHAPTER 21 OF THE ZONING ORDINANCES FOR THE TOWN OF SULLIVAN’S ISLAND”
  • Who permits septicLocal

    Septic tanks inside Sullivan's Island town limits.

    • The Town prohibits installation, maintenance, and use of a septic tank.
    “No person shall install, maintain or use a septic tank in the town.”
  • Off-grid sanitationProhibited

    Septic-tank-based off-grid sanitation inside Sullivan's Island town limits.

    • The claim concerns septic tanks; the code also requires covered properties to connect to Town public sewer.
    “No person shall install, maintain or use a septic tank in the town.”
  • Mandatory utility hookupSewer (with conditions)

    Houses, buildings, and properties used for human occupancy, employment, commercial, recreation, or similar purposes inside Sullivan's Island town limits.

    • Connection is at the owner's expense.
    • Sewer service must be contracted before connection or discharge.
    • The Town need not extend sewer to undeveloped lots without adjacent sewer lines; an extension requires a Town-owner agreement, payment agreement, Town approval of specifications, and final installation.
    “and to be connected to the public sewer system of the town.”
  • Subdividing landRegulated (with conditions)

    Subdivision proposals inside Sullivan's Island town limits.

    • Proposals must minimize flood damage, provide utilities and facilities located and constructed to minimize flood damage, and provide adequate drainage.
    • Base-flood-elevation data is required for a subdivision proposal or other proposed development greater than the lesser of 50 lots or five acres.

    base flood elevation data threshold: greater than the lesser of 50 lots or five acres (Subdivision proposals and other proposed development, including manufactured home parks and subdivisions.)

    “All subdivision proposals shall be consistent with the need to minimize flood damage.”
  • Building in a floodplainRequired

    Development activities subject to the Town Flood Damage Prevention chapter inside Sullivan's Island town limits.

    • A building/development permit is required before development activities begin.
    • The chapter's application and certification procedures apply.
    “A building/development permit shall be required in conformance with the provision of this chapter prior to the commencement of any development activities.”
  • Permit feesVariable (with conditions)

    Town building and electrical permits.

    • The applicable fee is the amount established by the currently effective Town Council resolution.
    “an applicant shall pay the fee for said permit, which has been established by the currently effective resolution of Town Council.”
  • Permit processPublished (with conditions)

    Building-permit applications inside Sullivan's Island town limits.

    • Application is in writing to the Building Inspector or representative at Town Hall on approved forms.
    • Plans and specifications describing the proposal accompany the application; the Inspector may request approximate cost supported by bids or detailed estimates.
    • For property wholly or partly seaward of the SCCC 40-year setback line, plans must show prescribed SCCC lines and the applicant must provide written SCCC approval where required.
    “Application for a building permit shall be made in writing to the Building Inspector or his or her designated representative at the Town Hall”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Town of Sullivan's Island or Charleston County directly.

  • Owner-builder exemption — Owner-built residential construction inside Sullivan's Island town limits.
  • Inspections — Construction inside Sullivan's Island town limits.
  • Minimum dwelling size — Residential districts inside Sullivan's Island town limits.
  • Minimum lot size — Residential districts inside Sullivan's Island town limits.
  • Setbacks — Residential districts inside Sullivan's Island town limits.
13 more unanswered
  • Lot coverage
  • Building height
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Septic permit
  • Septic inspection
  • Well permit
  • Agricultural exemption
  • Driveway access
  • Short-term rentals

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 Town of Sullivan's Island publishes no rule on the point, not that none exists. Charleston County’s page lists the county offices to call.

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