Unincorporated Grant County, South Dakota requires a county building permit before excavation, construction, moving or alteration of a building or accessory building begins.1 The Grant County Planning & Zoning Office issues building permits and also administers the county's zoning, subdivision and drainage rules.2 Septic systems are governed by South Dakota requirements, while the exact review path depends on the proposed system.3
At a glance
- Building permit
- Required before covered building work begins in unincorporated Grant County1
- Zoning
- County zoning applies in unincorporated areas4
- Septic
- South Dakota administers minimum on-site wastewater requirements; ask the county about any stricter local requirements3
- Owner electrical work
- A qualifying resident owner may do the work with an approved homeowner permit and required inspections5
- Manufactured homes
- County size, foundation, anchoring, design and age conditions vary by classification6
- Private well
- A state water-right permit may be required before drilling, depending on the proposed water use7
- Road access
- Driveway spacing applies, and access from a state highway requires state approval before a county building or use permit8
Who to call
Planning & zoning
Grant County Planning & Zoning Office
Building permits, zoning, plats, site plans, drainage applications, 911 addresses and floodplain administration
210 E 5th Ave, Milbank, SD 57252
Septic permits
South Dakota DANR On-Site Wastewater Systems
State on-site wastewater system requirements and plan-review questions
Contact details are copied from each office’s official page and were checked against it on September 27, 2026.
Do you need a building permit in Grant County, South Dakota?
Yes. In unincorporated Grant County, excavation, construction, moving or alteration of a building or accessory building cannot begin until the County Zoning Officer issues a building permit.1 The permit must be displayed where it is visible from a public right-of-way.1 A permit expires if work has not begun within 180 days, and the ordinance also sets a one-year substantial-completion deadline.1
The county ordinance does not establish one general countywide construction code for every project; it instead identifies code requirements for certain regulated uses and structures.9 State electrical and plumbing requirements can still apply separately from the county land-use permit.1011 Grant County's general structural-inspection and certificate-of-occupancy requirements could not be confirmed, so ask Planning & Zoning what inspections and closeout documents apply to the specific project.2
Who issues building permits in Grant County, South Dakota?
The Grant County Planning & Zoning Office issues building permits and administers the comprehensive land-use plan, subdivision ordinance, zoning ordinance and drainage ordinance.2 The office also reviews plats and site plans, assigns addresses for new construction and serves as the Floodplain Administrator.2
Building-permit applications are available for pickup each day and are approved by the Planning & Zoning Officer after review.2 Contact the office at (605) 432-7580 or [email protected], or visit 210 E 5th Ave, Milbank, SD 57252.2 Ask which application, site plan, zoning-district standards, fees and inspections fit the proposed use before ordering materials.2 Incorporated municipalities may administer their own land-use rules, so a parcel inside a city should start with that municipality rather than the county process described here.4
Does Grant County, South Dakota have zoning?
Yes. Grant County's zoning ordinance applies to unincorporated land and divides that territory into agricultural, commercial or industrial, natural-resources, planned-development and aquifer-protection districts.412 Rules depend on the zoning district and proposed use, so the zoning map and parcel classification matter before design begins.12
The ordinance contains district- and use-specific setbacks rather than one setback that fits every parcel.13 In the Agricultural District, the cited height rule limits a main building to 35 feet or two and one-half stories, with listed exceptions including agricultural buildings and other structures not used for human occupancy.14 The ordinance also gives special minimum lot sizes to uses such as certain animal-feeding operations and private campgrounds; those thresholds are not a universal residential minimum lot size.15 Ask Planning & Zoning to confirm the district, allowed use, setbacks and access standards for the exact parcel.2
How do septic systems work in Grant County, South Dakota?
South Dakota administers minimum requirements for individual and small on-site wastewater systems, and local governments may impose stricter standards.3 The state septic program says South Dakota has installation requirements and a certification program for septic-system installers.16 Contact the state on-site wastewater program at (605) 773-4647 for system-review questions, then ask Grant County Planning & Zoning whether a local review applies to the parcel.162
A universal septic-permit or inspection path for every Grant County system could not be confirmed. The site still needs careful evaluation: only about 6.3% of county soils are rated without severe limitations for a conventional septic drain field.17 That soil statistic does not decide whether an individual site will pass, but it makes early soil and system planning prudent.17 Where water or electrical service is unavailable, state rules allow specified unconventional sanitation systems under conditions, and experimental systems require state approval before installation.18
Can you live in an RV or tiny home in Grant County, South Dakota?
Grant County's general rule for living long-term in an RV on private land could not be confirmed, and the private-campground provisions do not answer that question for an individual parcel. Ask the Grant County Planning & Zoning Office whether the proposed stay is an allowed principal, accessory or temporary use in the parcel's district before placing an RV.2
A county rule expressly addressing tiny-home occupancy also could not be confirmed. A tiny home still falls within the county permit and zoning process when the project involves covered construction, moving or alteration of a building.1 Manufactured homes have separate classifications: Type A homes must exceed 1,200 square feet, Type B homes must exceed 700 square feet, and both classifications carry additional placement and design conditions.6 Those manufactured-home thresholds are not a general minimum size for every site-built dwelling.19 Confirm how the county classifies the proposed unit before purchase.2
What are the steps to build a home in Grant County, South Dakota?
- Confirm that the parcel is outside an incorporated municipality and ask Grant County Planning & Zoning for its district, allowed use, setbacks and site-plan requirements.42
- Verify legal access and driveway placement; a state-highway connection needs South Dakota Department of Transportation approval before the county issues a building or use permit.8
- Plan water and wastewater early because a water-right permit may be required before well drilling, while septic work is subject to state minimum requirements and possible stricter local standards.73
- Submit the county building-permit application and wait for approval before excavation or covered building work begins.120
- Arrange state electrical and plumbing permits or inspections that apply; qualifying owner-occupants may perform their own electrical work only under the homeowner-permit conditions.21115
- Ask Planning & Zoning which county inspections and occupancy closeout apply because a general county process could not be confirmed.2
What should you check before buying land in Grant County, South Dakota?
Start with the zoning map, allowed use, setbacks and the ability to obtain a driveway that meets county spacing rules.12138 If the parcel touches a state highway, state access approval is required before a plat is filed or a county building or use permit is issued.8
Treat wastewater feasibility as an early purchase contingency because about 6.3% of county soils are rated without severe limitations for a conventional drain field.17 Ask whether the parcel lies in a regulated floodplain because the county Planning & Zoning Office serves as Floodplain Administrator, while South Dakota describes permits as required for development in participating floodplain communities.222 Confirm the proposed water use before drilling because some uses require an approved state water-right permit first.7 For carrying costs, the county's effective property-tax rate is about 0.9%, with a median annual property-tax bill of $1,527.2324
Watch-outs
- Do not start excavation or covered building work before the county permit is issued; the permit must be displayed where it can be seen from a public right-of-way.1
- A qualifying electrical owner exemption waives licensure, not the homeowner permit or inspection requirements.5
- Grant County's general rules for residential RV use, tiny-home occupancy and county structural inspections could not be confirmed; ask Planning & Zoning before relying on any of those uses or processes.2
Sources
- Grant County Compiled Zoning Ordinance, quoted and re-checked
- Grant County Planning & Zoning Office (grantcounty.sd.gov)
- On-Site Wastewater Systems in South Dakota (South Dakota statewide rule), quoted and re-checked
- Planning & Zoning - Grant County, quoted and re-checked
- South Dakota Electrical Commission - Homeowner Wiring (South Dakota statewide rule), quoted and re-checked
- Grant County Compiled Zoning Ordinance, quoted and re-checked
- South Dakota Water Rights - Drilling a Well, quoted and re-checked
- Grant County Compiled Zoning Ordinance, quoted and re-checked
- Grant County Compiled Zoning Ordinance, quoted and re-checked
- South Dakota Electrical Commission - Homeowner Wiring (South Dakota statewide rule), quoted and re-checked
- South Dakota Plumbing Commission - Inspections (South Dakota statewide rule), quoted and re-checked
- Grant County Compiled Zoning Ordinance, quoted and re-checked
- Grant County Compiled Zoning Ordinance, quoted and re-checked
- Grant County Compiled Zoning Ordinance, quoted and re-checked
- Grant County Compiled Zoning Ordinance, quoted and re-checked
- South Dakota DANR On-Site Wastewater Systems (danr.sd.gov)
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
- Administrative Rule 74:53:01 — Individual and Small On-Site Wastewater Systems (South Dakota statewide rule), quoted and re-checked
- Grant County Compiled Zoning Ordinance, quoted and re-checked
- Planning & Zoning - Grant County, quoted and re-checked
- South Dakota Electrical Wiring Rules Bulletin (South Dakota statewide rule), quoted and re-checked
- National Flood Insurance Program (South Dakota statewide rule), quoted and re-checked
- Effective property tax rate: Bolthole Index county data
- Median property tax bill: Bolthole Index county data
Written September 27, 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.