Building on Raw Land in Custer County, South Dakota

No building code doesn't mean no building permit

It's easy to read "no adopted building code" as "no permit process," and in Custer County that would be a costly assumption. The county's Planning and Economic Development office still requires a Residential Building Permit application before construction begins on a new home, even though there's no adopted code specifying construction standards to inspect against. In practice, that means the county's permit review is checking things like setback compliance, septic sign-off, and basic site information rather than a detailed building-code plan review -- but skipping the application itself is still a permit violation, not a gray area created by the lack of a code.

The county calculates its building permit fee using a straightforward formula published in its fee schedule: total square footage of the structure multiplied by a per-square-foot rate, plus a flat $100. Because that per-square-foot rate is set in an annually reviewed fee schedule (the county has published updated versions for the 2025-2026 cycle), don't rely on an old fee sheet or a figure quoted by a builder from a prior year -- confirm the current rate with the Planning and Economic Development office before budgeting your permit cost.

Septic comes first, in practice, even though it's a separate permit

Custer County's On-Site Wastewater Treatment System (OWTS) permit is administered by the same Planning office as the building permit, but it has its own process and its own failure points worth planning around. Before a system can be installed, a site evaluation by a Planning Department representative is required, incorporating a percolation (perc) test using the county's own Perc Test Worksheet to establish the soil's absorption characteristics -- this determines both whether a standard system will work on the site and how it must be sized. The minimum lot size for a septic system in the county is one acre, and only a state-certified installer may perform the work.

One detail worth knowing before you schedule anything: required permit fees must be paid before work begins, and if the county's inspector arrives for a scheduled site visit or inspection and can't locate the site -- because it's unmarked, the access road isn't obvious, or the address doesn't match GPS -- Custer County charges an additional $100 trip fee. On raw, unaddressed land, that's a real and avoidable cost; flag the site clearly (a marked stake, a visible address sign, or GPS coordinates shared in advance) before any scheduled county visit.

Sequencing: septic evaluation, then setbacks, then the building permit

Putting the pieces together, a practical build sequence on raw Custer County land runs: confirm the parcel's setback tier under County Ordinance #2 (the county's subdivision and land-use ordinance sets the applicable building setback based on parcel size), get the septic site evaluation and perc test scheduled and passed since your home's footprint and the leach field placement both depend on where the system can go, then submit the Residential Building Permit application referencing both the confirmed setback and the septic approval. Because there's no zoning ordinance to define separate districts or permitted-use categories, this permit-and-septic sequence -- not a zoning determination -- is effectively the county's entire land-use gate for new residential construction. Confirm current forms, fees, and required attachments directly with the Planning and Economic Development office before starting, since permit procedures and fee schedules are revised from time to time.