Middle planning scenario$529,635
Low / high stress scenarios$411,905 – $738,852
Planning allowances, not bids or a confidence interval. Includes 15% reserve. Land excluded.
Your project brief
1,800 sq ft conditioned living · 600 sq ft unconditioned shop · 240 sq ft covered porch.
Single story, slab-on-grade, simple footprint. standard finishes. Builder-managed coordination. Local building multiplier: 1× (user assumption).
Itemized planning budget
| Scope | Low | Planning | High |
|---|
| Shell & erection | $84,480 | $105,600 | $137,280 |
| Slab & foundation | $26,880 | $33,600 | $47,040 |
| Windows & exterior doors | $16,320 | $20,400 | $27,540 |
| Insulation & air sealing | $12,960 | $16,200 | $21,870 |
| Interior build-out & finishes | $80,640 | $100,800 | $136,080 |
| Electrical & lighting | $17,760 | $22,200 | $29,970 |
| Plumbing & fixtures | $13,600 | $17,000 | $23,800 |
| Heating, cooling & ventilation | $13,680 | $17,100 | $23,940 |
| Covered porch | $8,064 | $10,080 | $13,608 |
| Site preparation & drainage | $9,000 | $15,000 | $27,000 |
| Well / septic / utility connections | $12,000 | $20,000 | $36,000 |
| Driveway & site access | $5,200 | $8,000 | $12,800 |
| Permits & impact fees | $3,750 | $5,000 | $7,500 |
| Plans, engineering & surveys | $4,875 | $6,500 | $9,750 |
| Temporary services & cleanup | $3,375 | $4,500 | $6,750 |
| Other project costs | $0 | $0 | $0 |
| Builder management & overhead | $45,594 | $58,572 | $81,552 |
| Contingency reserve | $53,727 | $69,083 | $96,372 |
| Land purchase allowance | $0 | $0 | $0 |
| Total | $411,905 | $529,635 | $738,852 |
|---|
Amounts are displayed to the nearest dollar; rounded rows may differ slightly from the total. The workbook retains cents.
Scope behind each number
Shell & erection: Structure, roof, siding, erection and standard delivery/tax allowance for enclosed space. Excludes slab, openings, insulation, interior and porch.
Slab & foundation: One slab-on-grade foundation for living + shop. Footings, ordinary reinforcement, vapor control and slab labor included; major soil remediation excluded. Porch slab is in the porch line.
Windows & exterior doors: Separate allowances for residential windows/doors and basic shop doors. Verify exact quantities and overhead-door sizes.
Insulation & air sealing: Conditioned living area only. Confirm climate-specific assembly, moisture control and thermal bridging with the designer. Shop remains unconditioned.
Interior build-out & finishes: Interior framing, drywall, paint, floors, cabinets, counters, trim and appliance allowance. Plumbing fixtures are in plumbing; electrical and HVAC are separate.
Electrical & lighting: In-building wiring, standard fixtures and basic shop power. Utility service extension is in utilities. Specialty workshop equipment or EV upgrades need quotes.
Plumbing & fixtures: Interior plumbing, water heater and ordinary kitchen/bath fixtures. Assumes roughly two bathrooms; well, septic or municipal connections belong in utilities.
Heating, cooling & ventilation: Conditioned living space only, including a fixed equipment allowance. Shop heating/cooling and specialty filtration are excluded.
Covered porch: Porch structure, roof, slab and basic finish, counted once here. Excludes outdoor kitchen, screening and elaborate decking.
Site preparation & drainage: Your fixed local allowance for clearing, grading and normal drainage. Separate from land, the building slab and driveway. No automatic location multiplier.
Well / septic / utility connections: Your combined allowance for the utilities your parcel requires: power extension, water and wastewater. Use municipal connections OR well/septic, as appropriate.
Driveway & site access: Your allowance for construction access and a finished driveway. Verify length, surfacing, culverts and delivery access.
Permits & impact fees: Your local permit and impact-fee allowance. Utility connection fees should be placed in utilities only.
Plans, engineering & surveys: Your allowance for architectural plans, structural/site engineering, survey and soil testing. Remove any services already included elsewhere.
Temporary services & cleanup: Portable toilet, temporary power/water, dumpsters and final construction cleanup. Long-duration rentals or remote delivery premiums need separate pricing.
Other project costs: Your fixed allowance for applicable costs outside the other lines: financing/carrying costs, furnishings, landscaping, solar or specialty equipment. Identify the scope in your project notes; no automatic local multiplier or builder markup.
Builder management & overhead: 15% planning allowance on building and site work for general-contractor coordination, overhead and profit. Excludes permits, design, contingency and land. Remove this line if your whole-line bids already include this fee.
Contingency reserve: 15% of all non-land work, fees and management. A separate reserve in each scenario, not a statistical confidence interval.
Land purchase allowance: Excluded from this project total. Existing land value is not treated as construction savings.
What to resolve for this project
Replace assumptions with local bids. Every default is an editable planning allowance. The local multiplier is your assumption; it is not a measured ZIP-code or state price index.
Resolve the parcel before the floor plan. Soils, slope, flood conditions, utility distance and wastewater feasibility can move the budget beyond this range. Get parcel-specific feasibility and utility quotes.
Your shop is unconditioned. The shop gets a shell, slab, doors and basic electricity. Heating, cooling, plumbing, shop insulation and specialist equipment need additional allowances.
Your next steps
- Check the parcel and access. Confirm residential use, setbacks, easements, deed restrictions, flood conditions and heavy-delivery access with the relevant local offices.
- Price the ground and utilities. Get site and drainage, foundation/soils, power, water and wastewater quotes. Record distance, capacity, permit requirements and who pays connection fees.
- Write one common scope. Specify conditioned living, unconditioned shop and porch areas separately, plus foundation, eave height, roof, openings, insulation, finish schedule and responsibilities.
- Confirm parcel-specific design requirements. Ask the building department and designer about current design loads, foundation requirements, energy requirements, inspections and required stamped plans.
- Get comparable written bids. Use the same drawings and finish schedule. Mark each category included, excluded or unknown; identify allowances, taxes, freight and builder overhead.
- Resolve exclusions before signing. Confirm payment milestones, allowance adjustments, change orders, quote expiry, warranty, insurance, schedule and the person responsible for each excluded item.
Assumptions & limitations
- Single-story, simple rectangular new build on a slab. No basement, second floor, conversion, unusual spans or engineered site remediation.
- USD planning allowances including trade labor. Rates are editorial assumptions, not live bids, nationwide averages or measured local prices.
- Living space is fully conditioned; the shop is unconditioned. A covered porch includes its own slab and roof and is excluded from enclosed area.
- Local multiplier adjusts modeled building work only. Fixed site/soft allowances, land and custom overrides do not change with this multiplier.
- Low and high are scope/price stress scenarios; they are not probabilities, guarantees or a confidence interval. Each includes the selected contingency reserve.
- Financing interest and fees, carrying costs, furnishings, solar, pools, extensive landscaping and specialty equipment are excluded unless entered in Other project costs.
- An override replaces the whole line and preserves that line’s low/high uncertainty. Confirm bundled quotes do not duplicate other lines or builder overhead.
Sources
Hansen Pole Buildings planning guide
https://www.hansenpolebuildings.com/pdfs/Planning_Guide_HansenPoleBuildings.pdf
Separate the kit, erection, slab, utilities and finishes; confirm parcel and design requirements. Accessed 2026-09-24.
DC Structures: Pocatello kit scope
https://dcstructures.com/kits/pocatello/
A material package can bundle windows, doors and interior framing while excluding foundation, site work, installation and mechanical systems. Allocate bundled quotes across overlapping categories once. Accessed 2026-09-24.
Barns & Barndos: published 2026 pricing
https://barnsnbarndos.com/pricing
One supplier distinguishes materials-only kit prices from a completed build; its prices are not nationwide averages. Accessed 2026-09-24.
NAHB: Cost of Constructing a Home, 2024
https://www.nahb.org/-/media/AB4EFC742624475A97A0A62189986FF8.ashx
Broad construction categories and survey limitations. This survey is not a barndominium or state-level cost dataset. Accessed 2026-09-24.