What turnkey includes
- County and site approvals — zoning check, permit application and fees (passed through at cost), floodplain check, 911 address request, MoDOT or county entrance permit, septic permit with the soil evaluation the county requires.
- Site work — clearing, grading, driveway base, erosion control; well drilling by a Missouri-permitted driller; septic system by a registered installer; electric service coordination with Ameren or the co-op.
- Shell — post-frame structure engineered for Seismic Design Category C, 30-inch frost, the county's wind and snow values; metal roof and walls; doors and windows.
- Slab and foundation — thickened-edge slab with footings below frost, designed for the soil on the parcel.
- Interior — framing, plumbing, electrical, HVAC, insulation and vapor strategy, drywall, trim, flooring, kitchen and bath cabinetry, fixtures and appliances per the allowance schedule.
- Finish — final inspections and certificate of occupancy where the county issues one; fire-district sign-off where that is the authority; walkthrough.
Not included unless quoted: land, surveys and title, utility line-extension charges beyond the utility's free footage, outbuildings, fencing, landscaping, furniture, and allowance overages (every allowance is a line you can see and change before contract).
How the county changes the job
| County | What turnkey has to carry |
|---|---|
| Franklin | 2021 IRC plan review; stamped design; $25 application + square-footage fee + $350 escrow; the county's inspection schedule; county sewage permit under the ordinance effective October 2025 |
| Jefferson | 2015 IRC per published code (edition confirmed at application); fee on a valuation floor of $120/sq ft; RA-5 five-acre check; inspections |
| Warren | Septic permit ($200) issued first; structure permit ($150); 911 address; no county inspections; permanent electric sticker after the Sanitarian's septic final; Warrenton and Wright City fire districts issue their own permits in their areas |
| Lincoln | No county permits; floodplain permit if in a mapped area; Health Department septic permit; fire-district electrical and occupancy sign-off; city rules inside Troy, Moscow Mills, Winfield, Elsberry |
| St. Charles | 2021 county residential code; A-district five-acre and 800 sq ft minimums; private sewage code permit; inspections |
Details and sources: permits and codes by county.
Price bands (2026, St. Louis ring)
| Scope | Per sq ft |
|---|---|
| Turnkey living area | $160 – $230 |
| Finished shop area (if included) | $55 – $80 |
| Blended, living + shop | $130 – $200 |
| Site package (septic, well, driveway and entrance, electric, clearing/grading) | $30,000 – $80,000 per project |
Worked examples at the cost guide: a 2,000-square-foot living area with a 1,200-square-foot shop runs about $420,000–$640,000 all-in. Lenders fund turnkey through construction-to-permanent loans with 10–20% down; see financing and appraisal.
Timeline
Nine to fifteen months land-to-keys is our planning assumption in the ring. The long poles, in order: the septic soil evaluation and design (schedule it before you close on land), the county's plan review where there is one, the well, electric service, and the shell lead time. Franklin County permits run 365 days; Warren's septic permit expires in a year. Build timeline by county.
Not ready to talk yet?
Start with the planning layer: the complete St. Louis barndominium guide, then comparing builder bids so you can hold every bid — including ours — to the same scope.
Frequently asked questions
Do you build in cities? Where the city allows it. Arnold banned metal-sided homes in 2021; other cities have design standards; subdivisions have covenants. We check before quoting.
Can I supply my own plan? Yes, if it is engineered for SDC C and the county's wind and snow values, or we have it re-stamped.
What if the soil fails the septic evaluation? Then the land is the problem, not the house. That is why the evaluation comes first, before the land contract closes, with a contingency.
Do you need ten acres? No — the county's minimum (three to five acres on rural zoning) is the rule. Ten acres is Farm Credit's lending requirement, not a building one.