{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://askcalculators.com/uk/heating-comparison/schema.json",
  "title": "Heating Cost Comparison Calculator — United Kingdom inputs",
  "description": "Put electricity and the comparison fuel on the same delivered-heat basis instead of comparing unlike fuel units. GBP planning view; stated limitations apply.",
  "type": "object",
  "properties": {
    "usefulHeat": {
      "title": "Annual useful heat required, kWh",
      "type": "number",
      "description": "Illustrative starting value; replace with your own evidence.",
      "default": 18000,
      "minimum": 0,
      "maximum": 1000000000000,
      "x-step": 0.01
    },
    "heatPumpCop": {
      "title": "Seasonal heat-pump coefficient of performance",
      "type": "number",
      "description": "Illustrative starting value; replace with your own evidence.",
      "default": 3,
      "minimum": 0.5,
      "maximum": 8,
      "x-step": 0.01
    },
    "fuelEfficiency": {
      "title": "Seasonal comparison-heater efficiency",
      "type": "number",
      "description": "Illustrative starting value; replace with your own evidence.",
      "default": 90,
      "minimum": 0,
      "maximum": 100,
      "x-step": 0.1,
      "x-unit": "percent"
    },
    "electricityRate": {
      "title": "Electricity price per input kWh",
      "type": "number",
      "description": "Illustrative starting value; replace with your own evidence.",
      "default": 0.2,
      "minimum": 0,
      "maximum": 1000000000000,
      "x-step": 0.01,
      "x-prefix": "GBP",
      "x-unit": "currency"
    },
    "fuelRate": {
      "title": "Comparison fuel price per input kWh",
      "type": "number",
      "description": "Illustrative starting value; replace with your own evidence.",
      "default": 0.08,
      "minimum": 0,
      "maximum": 1000000000000,
      "x-step": 0.01,
      "x-prefix": "GBP",
      "x-unit": "currency"
    },
    "electricFixed": {
      "title": "Annual additional electric fixed charges",
      "type": "number",
      "description": "Illustrative starting value; replace with your own evidence.",
      "default": 0,
      "minimum": 0,
      "maximum": 1000000000000,
      "x-step": 0.01,
      "x-prefix": "GBP",
      "x-unit": "currency"
    },
    "fuelFixed": {
      "title": "Annual fuel fixed charges",
      "type": "number",
      "description": "Illustrative starting value; replace with your own evidence.",
      "default": 120,
      "minimum": 0,
      "maximum": 1000000000000,
      "x-step": 0.01,
      "x-prefix": "GBP",
      "x-unit": "currency"
    }
  },
  "required": [
    "usefulHeat",
    "heatPumpCop",
    "fuelEfficiency",
    "electricityRate",
    "fuelRate",
    "electricFixed",
    "fuelFixed"
  ],
  "additionalProperties": false,
  "x-askcalculators": {
    "version": "20.16.0",
    "calculatorUrl": "https://askcalculators.com/uk/heating-comparison/",
    "queryExample": "https://askcalculators.com/uk/heating-comparison/?usefulHeat=18000&heatPumpCop=3&fuelEfficiency=90&electricityRate=0.2&fuelRate=0.08&electricFixed=0&fuelFixed=120",
    "migrationStatus": "new",
    "reviewStatus": "pending",
    "pageStatus": "live",
    "workStatus": "pending",
    "formula": {
      "expression": "input energy = useful heat ÷ seasonal efficiency; cost = input energy × unit price + fixed charges.",
      "note": "Inputs are converted to canonical units before evaluating this stated formula."
    },
    "quality": {
      "availability": "live",
      "technicalReviewRecord": "/reviews/v20-uk-heating-comparison.json",
      "qualifiedReview": "pending",
      "qualifiedReviewer": null,
      "qualifiedReviewDate": null,
      "formulaVersion": "20.16.0",
      "referenceCoverage": "references-listed",
      "releaseTestScope": "Catalog and regression checks are not a professional formula audit; consult release evidence.",
      "historicalMetadataDate": "",
      "historicalMetadataNotice": "The imported date is not evidence of a completed human review."
    },
    "outputs": {
      "heatPumpEnergy": {
        "title": "Heat-pump input electricity, kWh",
        "type": "number",
        "x-format": "number",
        "x-digits": 2
      },
      "fuelEnergy": {
        "title": "Comparison fuel input, kWh",
        "type": "number",
        "x-format": "number",
        "x-digits": 2
      },
      "heatPumpCost": {
        "title": "Heat-pump annual cost",
        "type": "number",
        "x-format": "currency",
        "x-currency": "GBP",
        "x-digits": 2
      },
      "fuelCost": {
        "title": "Comparison heater annual cost",
        "type": "number",
        "x-format": "currency",
        "x-currency": "GBP",
        "x-digits": 2
      },
      "annualSaving": {
        "title": "Heat-pump annual saving",
        "type": "number",
        "x-format": "currency",
        "x-currency": "GBP",
        "x-digits": 2,
        "x-primary": true
      },
      "breakevenCop": {
        "title": "Energy-only break-even COP",
        "type": "number",
        "x-format": "number",
        "x-digits": 2
      }
    }
  }
}