{
  "slug": "buy-vs-build-house-cost",
  "title": "Buy vs Build a House Cost Calculator",
  "heading": "Buy vs Build a House Cost Calculator",
  "category": "financial",
  "url": "https://www.revenuelab.fyi/toolbox/buy-vs-build-house-cost",
  "summary": "Compare buying an existing home against building new — land, construction, carrying costs, and immediate repairs.",
  "description": "Buying an existing home and building new rarely compare cleanly, because the costs sit in different places. Buying carries a purchase price, closing costs, and a repair-and-update bill that most buyers underestimate in the first two years. Building carries land, site work, hard construction cost per square foot, soft costs like permits, plans, and impact fees, plus months of carrying two housing payments — construction loan interest on one side and rent or an existing mortgage on the other. This calculator puts both paths on a single all-in number, including that carrying period, so you can see the real gap rather than comparing a listing price to a builder's base price per square foot. 2026 US national build costs commonly run $160-$280 per square foot for the structure alone, before land.",
  "formula": "Buy Total = Price + Closing% × Price + Immediate Repairs. Build Total = Land + (Sq Ft × Build Rate) + Site Work + Soft Costs + (Months × Monthly Carrying Cost).",
  "dateModified": "2026-09-06",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=buy-vs-build-house-cost",
  "inputs": [
    {
      "id": "buyPrice",
      "label": "Existing home purchase price",
      "kind": "number",
      "hint": null,
      "default": 425000,
      "unit": "$",
      "min": 20000,
      "max": 5000000
    },
    {
      "id": "closingPct",
      "label": "Closing costs",
      "kind": "number",
      "hint": null,
      "default": 3,
      "unit": "%",
      "min": 0,
      "max": 8
    },
    {
      "id": "repairs",
      "label": "Immediate repairs and updates",
      "kind": "number",
      "hint": null,
      "default": 35000,
      "unit": "$",
      "min": 0,
      "max": 500000
    },
    {
      "id": "landCost",
      "label": "Land cost",
      "kind": "number",
      "hint": null,
      "default": 110000,
      "unit": "$",
      "min": 0,
      "max": 3000000
    },
    {
      "id": "sqft",
      "label": "New home size",
      "kind": "number",
      "hint": null,
      "default": 2200,
      "unit": "sq ft",
      "min": 400,
      "max": 12000
    },
    {
      "id": "buildRate",
      "label": "Construction cost",
      "kind": "number",
      "hint": null,
      "default": 195,
      "unit": "$/sq ft",
      "min": 80,
      "max": 600
    },
    {
      "id": "siteWork",
      "label": "Site work, well, septic, driveway",
      "kind": "number",
      "hint": null,
      "default": 45000,
      "unit": "$",
      "min": 0,
      "max": 500000
    },
    {
      "id": "softCosts",
      "label": "Plans, permits, impact fees",
      "kind": "number",
      "hint": null,
      "default": 28000,
      "unit": "$",
      "min": 0,
      "max": 300000
    },
    {
      "id": "buildMonths",
      "label": "Build duration",
      "kind": "number",
      "hint": null,
      "default": 10,
      "unit": "months",
      "min": 3,
      "max": 36
    },
    {
      "id": "carryMonthly",
      "label": "Monthly carrying cost during build",
      "kind": "number",
      "hint": null,
      "default": 2600,
      "unit": "$",
      "min": 0,
      "max": 20000
    }
  ],
  "outputs": [
    {
      "id": "difference",
      "label": "Build cost minus buy cost",
      "format": "currency",
      "hint": null,
      "primary": true
    },
    {
      "id": "cheaper",
      "label": "Lower all-in cost",
      "format": "raw",
      "hint": null,
      "primary": false
    },
    {
      "id": "buyTotal",
      "label": "All-in cost to buy existing",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "buildTotal",
      "label": "All-in cost to build new",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "carrying",
      "label": "Carrying cost during construction",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "buildPerSqFt",
      "label": "Build cost per sq ft (all-in)",
      "format": "currency",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Existing home purchase price: 425000 $",
      "Closing costs: 3 %",
      "Immediate repairs and updates: 35000 $",
      "Land cost: 110000 $",
      "New home size: 2200 sq ft",
      "Construction cost: 195 $/sq ft",
      "Site work, well, septic, driveway: 45000 $",
      "Plans, permits, impact fees: 28000 $",
      "Build duration: 10 months",
      "Monthly carrying cost during build: 2600 $"
    ],
    "outputs": [
      "Build cost minus buy cost: $165,250",
      "Lower all-in cost: Buying existing",
      "All-in cost to buy existing: $472,750",
      "All-in cost to build new: $638,000",
      "Carrying cost during construction: $26,000",
      "Build cost per sq ft (all-in): $290"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter existing home purchase price ($).",
      "Enter closing costs (%).",
      "Enter immediate repairs and updates ($).",
      "Enter land cost ($).",
      "Enter new home size (sq ft).",
      "Enter construction cost ($/sq ft).",
      "Enter site work, well, septic, driveway ($).",
      "Enter plans, permits, impact fees ($).",
      "Enter build duration (months).",
      "Enter monthly carrying cost during build ($).",
      "Read your build cost minus buy cost on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "buyPrice": 255000,
        "closingPct": 1.7999999999999998,
        "repairs": 21000,
        "landCost": 65000,
        "sqft": 1300,
        "buildRate": 115,
        "siteWork": 27000,
        "softCosts": 17000,
        "buildMonths": 6,
        "carryMonthly": 1600
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "buyPrice": 425000,
        "closingPct": 3,
        "repairs": 35000,
        "landCost": 110000,
        "sqft": 2200,
        "buildRate": 195,
        "siteWork": 45000,
        "softCosts": 28000,
        "buildMonths": 10,
        "carryMonthly": 2600
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "buyPrice": 680000,
        "closingPct": 4.800000000000001,
        "repairs": 56000,
        "landCost": 175000,
        "sqft": 3500,
        "buildRate": 310,
        "siteWork": 72000,
        "softCosts": 45000,
        "buildMonths": 16,
        "carryMonthly": 4200
      }
    }
  ],
  "limitations": [
    "Results are estimates before tax, fees, and inflation unless an input explicitly covers them.",
    "Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.",
    "This is educational maths, not financial advice. Check anything contractual with the lender or your accountant."
  ],
  "faq": [
    {
      "q": "Is it cheaper to buy or build in 2026?",
      "a": "In most US metros buying existing is still cheaper per square foot, because existing homes were built at lower material and labor costs. Building wins more often in rural areas with inexpensive land, and whenever the existing inventory needs a gut renovation anyway."
    },
    {
      "q": "What do people forget when budgeting a build?",
      "a": "Site work and soft costs. A builder's per-square-foot number usually covers the structure, not the well, septic, driveway, grading, utility hookups, permits, or impact fees — those routinely add $50,000 or more."
    },
    {
      "q": "Why include carrying cost?",
      "a": "You pay for housing during construction. Ten months of rent or an existing mortgage plus construction loan interest is real money that never shows up in a builder's quote, and it is often the single largest hidden line in the comparison."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/buy-vs-rent-home-cost",
    "https://www.revenuelab.fyi/toolbox/sell-vs-rent-your-house-cost"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Buy vs Build a House Cost Calculator (https://www.revenuelab.fyi/toolbox/buy-vs-build-house-cost)"
}