Build Cost Calculator

Build Cost Contract v1

Build cost computed as GIA * indicative cost per sqm with contingency uplift.

Calculator v1 is active with deterministic local formulas and Grid/STAKR-ready contract output.

Contract

{
  "calculatorId": "build_cost_v1",
  "status": "ready_for_grid",
  "metadata": {
    "verticalKey": "landguide",
    "calculatorKind": "build_cost",
    "source": "landguide.calculator",
    "gridHandoffEligible": true,
    "stakrHandoffEligible": true,
    "generatedAtIso": "2026-05-24T15:43:48.025Z"
  },
  "context": {
    "assessmentId": "assessment_demo",
    "actorKey": "customer_demo",
    "reportId": "report_assessment_demo",
    "currencyCode": "GBP"
  },
  "input": {
    "grossInternalAreaSqm": 610,
    "indicativeCostPerSqm": 1750,
    "contingencyPct": 12.5
  },
  "output": {
    "provisionalBuildCost": 1200937.5,
    "notes": [
      "Build cost v1 formula: grossInternalAreaSqm * indicativeCostPerSqm * (1 + contingencyPct/100)."
    ]
  }
}

Grid-Ready Payload Scaffold

{
  "verticalKey": "landguide",
  "source": "landguide.calculator",
  "eventType": "calculator.scaffolded",
  "gridHandoffEligible": true,
  "stakrHandoffEligible": true,
  "payload": {
    "calculatorId": "build_cost_v1",
    "calculatorKind": "build_cost",
    "status": "ready_for_grid",
    "context": {
      "assessmentId": "assessment_demo",
      "actorKey": "customer_demo",
      "reportId": "report_assessment_demo",
      "currencyCode": "GBP"
    },
    "input": {
      "grossInternalAreaSqm": 610,
      "indicativeCostPerSqm": 1750,
      "contingencyPct": 12.5
    },
    "output": {
      "provisionalBuildCost": 1200937.5,
      "notes": [
        "Build cost v1 formula: grossInternalAreaSqm * indicativeCostPerSqm * (1 + contingencyPct/100)."
      ]
    }
  }
}