{
  "apiVersion": "1.0.0",
  "kind": "residential-energy-decision",
  "jurisdiction": "DE",
  "decision": "Replace the gas boiler",
  "why": [
    "The monthly energy budget falls from €368 to €225, a difference of €143 — financing of the equipment included.",
    "Public support covers 35 % of the eligible cost under the German BEG rules.",
    "A 10.582 kW heat pump covers a calculated heat load of 9.1 kW at a flow temperature of 52 °C, giving a seasonal performance factor of 3.8."
  ],
  "basedOn": "0 of 19 inputs answered",
  "recommendation": {
    "option": "full_system",
    "label": "Full system with solar and storage",
    "summary": "Heat pump, storage, battery and a solar array sized to the roof. Highest amount to finance, lowest running cost.",
    "monthlyBudget": 225,
    "currency": "EUR"
  },
  "alternatives": [
    {
      "option": "heating_only",
      "label": "Heat pump and storage only",
      "summary": "Replace the heat source. No solar, no battery, lowest amount to finance.",
      "recommended": false,
      "monthlyBudget": 295,
      "differenceToCurrent": 73,
      "equipment": 11400,
      "publicSupportShare": 0.35,
      "solarPanels": 0,
      "batteryKwh": 32,
      "installedByIone": true
    },
    {
      "option": "full_system",
      "label": "Full system with solar and storage",
      "summary": "Heat pump, storage, battery and a solar array sized to the roof. Highest amount to finance, lowest running cost.",
      "recommended": true,
      "monthlyBudget": 225,
      "differenceToCurrent": 143,
      "equipment": 10362,
      "publicSupportShare": 0.35,
      "solarPanels": 0,
      "batteryKwh": 32,
      "installedByIone": true
    },
    {
      "option": "equipment_only",
      "label": "Equipment only, own trades install",
      "summary": "iONE supplies and commissions; the household arranges installation and claims the public support itself.",
      "recommended": false,
      "monthlyBudget": 95,
      "differenceToCurrent": 273,
      "equipment": 10362,
      "publicSupportShare": 0.35,
      "solarPanels": 0,
      "batteryKwh": 32,
      "installedByIone": false
    }
  ],
  "components": {
    "heatPump": {
      "outputKw": 10.582,
      "designHeatLoadKw": 9.1,
      "flowTemperatureC": 52,
      "seasonalPerformanceFactor": 3.8,
      "refrigerant": "R290"
    },
    "thermalStorage": {
      "litres": 200
    },
    "hotWater": {
      "source": "heat pump",
      "storedC": 50
    },
    "battery": {
      "usableKwh": 32
    },
    "solar": {
      "panels": 0,
      "arrayKw": 0,
      "panelKw": 0.72,
      "roofCapacityPanels": 0,
      "limitedByRoof": false,
      "mpptKw": 0,
      "surfaces": [
        {
          "aspect": 0,
          "area": 0,
          "maxPanels": 0,
          "panels": 0,
          "yieldPerKwp": 0
        },
        {
          "aspect": 180,
          "area": 0,
          "maxPanels": 0,
          "panels": 0,
          "yieldPerKwp": 0
        }
      ]
    },
    "emitters": {
      "circuit": "radiators",
      "fanCoils": 0,
      "fanCoilsSuppliedByIone": false,
      "coolingIncluded": false
    },
    "itemised": [
      {
        "kind": "heat_pump",
        "name": "CGK-050V4P",
        "manufacturer": "",
        "capacity": 10.582,
        "unit": "kW",
        "quantity": 1,
        "equipment": 5000,
        "installation": 1500,
        "fromCatalog": true,
        "priced": true
      },
      {
        "kind": "thermal_storage",
        "name": "Buffer tank 200 l",
        "manufacturer": "",
        "capacity": 200,
        "unit": "l",
        "quantity": 1,
        "equipment": 1400,
        "installation": 420,
        "fromCatalog": true,
        "priced": true
      },
      {
        "kind": "battery",
        "name": "Battery 32 kWh + 12 kW inverter",
        "manufacturer": "",
        "capacity": 32,
        "unit": "kWh",
        "quantity": 1,
        "equipment": 5000,
        "installation": 1500,
        "fromCatalog": true,
        "priced": true
      }
    ]
  },
  "economics": {
    "currency": "EUR",
    "pricesIncludeVat": true,
    "equipment": 10362,
    "installation": {
      "low": 3420,
      "high": 3420
    },
    "commissioning": 0,
    "publicSupport": {
      "low": 2550,
      "high": 2550
    },
    "publicSupportShare": 0.35,
    "publicSupportClaimedByIone": true,
    "vatRelief": 1038,
    "financedAmount": 11232,
    "financingMonths": 180,
    "monthlyBudget": {
      "financing": 94,
      "energy": 133,
      "total": 225,
      "currentSystem": 368,
      "difference": 143
    },
    "annualEnergy": {
      "spaceHeatingKwh": 19200,
      "hotWaterKwh": 1800,
      "coolingKwh": 0,
      "gridImportKwh": 6238,
      "solarProductionKwh": 0,
      "solarSelfUsedKwh": 0,
      "solarCurtailedKwh": 0,
      "arrayOversized": false
    }
  },
  "missingInformation": [
    {
      "field": "insulation",
      "ask": "Has the building been insulated since it was built?",
      "allowed": [
        "original",
        "partly",
        "good",
        "new"
      ],
      "changesMonthlyBudgetBy": {
        "low": 220,
        "high": 340,
        "currency": "EUR",
        "per": "month"
      },
      "whyItMatters": "Answering this narrows the monthly figure from a €120 spread to a single number.",
      "assumedMeanwhile": "partly"
    },
    {
      "field": "constructionEra",
      "ask": "When was the building built?",
      "allowed": [
        "pre1979",
        "1979_1994",
        "1995_2009",
        "post2010"
      ],
      "changesMonthlyBudgetBy": {
        "low": 280,
        "high": 305,
        "currency": "EUR",
        "per": "month"
      },
      "whyItMatters": "Answering this narrows the monthly figure from a €25 spread to a single number.",
      "assumedMeanwhile": "1979_1994"
    },
    {
      "field": "existingEmitters",
      "ask": "What gives off the heat in the rooms — underfloor circuits, radiators or fan coils?",
      "allowed": [
        "underfloor",
        "radiators",
        "fancoils",
        "mixed"
      ],
      "changesMonthlyBudgetBy": {
        "low": 275,
        "high": 295,
        "currency": "EUR",
        "per": "month"
      },
      "whyItMatters": "Answering this narrows the monthly figure from a €20 spread to a single number.",
      "assumedMeanwhile": "radiators"
    },
    {
      "field": "currentHeating",
      "ask": "What heats the building today, and roughly how old is it?",
      "allowed": [
        "gas",
        "gas_old",
        "oil",
        "electric",
        "pellets",
        "coal",
        "heatpump"
      ],
      "changesMonthlyBudgetBy": {
        "low": 280,
        "high": 295,
        "currency": "EUR",
        "per": "month"
      },
      "whyItMatters": "Answering this narrows the monthly figure from a €15 spread to a single number.",
      "assumedMeanwhile": "gas"
    },
    {
      "field": "floorArea",
      "ask": "How large is the heated floor area, in m²?",
      "whyItMatters": "Used in the sizing; assumed until answered.",
      "assumedMeanwhile": 150
    },
    {
      "field": "roofAspect",
      "ask": "Which way does the main roof surface face?",
      "allowed": [
        "south",
        "south_east",
        "south_west",
        "east",
        "west",
        "north",
        "flat"
      ],
      "whyItMatters": "Used in the sizing; assumed until answered.",
      "assumedMeanwhile": "south"
    },
    {
      "field": "postcode",
      "ask": "Where is the property? A postcode is enough.",
      "whyItMatters": "Without it the solar yield is a national average instead of measured data for the location.",
      "assumedMeanwhile": ""
    }
  ],
  "nextQuestion": "Has the building been insulated since it was built?",
  "confidence": {
    "score": 0.55,
    "level": "medium",
    "derivedFrom": "missingInformation and the provenance of the prices",
    "reasons": [
      {
        "factor": "unanswered_questions",
        "effect": -0.45,
        "detail": "7 question(s) still open: insulation, constructionEra, existingEmitters, currentHeating, floorArea, roofAspect, postcode"
      }
    ],
    "statement": "Usable as an order of magnitude; some inputs or prices were assumed."
  },
  "assumptions": [
    {
      "label": "Specific heat demand",
      "value": "128 kWh/m²·a"
    },
    {
      "label": "Design flow temperature",
      "value": "52 °C"
    },
    {
      "label": "Seasonal performance factor",
      "value": "3.8 — from the unit datasheet"
    },
    {
      "label": "Electricity price assumed",
      "value": "0.29 €/kWh"
    },
    {
      "label": "Optimization saving assumed",
      "value": "12 %"
    },
    {
      "label": "Public support assumed",
      "value": "BEG 35 % of eligible cost"
    },
    {
      "label": "Financing assumed",
      "value": "15 years at 5.9 % nominal"
    }
  ],
  "sources": {
    "heatDemand": {
      "source": "iONE model",
      "method": "Specific demand by construction era and insulation level.",
      "status": "model"
    },
    "solarYield": {
      "source": "iONE model constant",
      "status": "assumed"
    },
    "prices": {
      "source": "iONE catalogue",
      "includesVat": true,
      "retrievedAt": "2026-09-11T20:32:09.036Z",
      "status": "catalogue"
    },
    "publicSupport": {
      "source": "BEG Heizungsförderung",
      "jurisdiction": "DE",
      "method": "Base rate plus bonuses, capped at 70 % and at €30,000 eligible cost.",
      "status": "rules"
    },
    "financing": {
      "months": 180,
      "nominalRate": 0.059,
      "status": "model",
      "note": "No financing partner is connected."
    },
    "electricityPrice": {
      "eurPerKwh": 0.29,
      "status": "assumed",
      "note": "No live tariff feed is connected."
    }
  },
  "disclaimer": "An estimate produced by a model, never a quotation. Final pricing depends on the building, installation requirements, financing approval, energy use and available public support."
}