> For the complete documentation index, see [llms.txt](https://docs.altum.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.altum.ai/english/sustainability/sustainability-api-v2-apartments/cost-indicators.md).

# Cost indicators

Depending on the supply chain partner handling the installation of measures it is possible to overwrite default values in regards to costs and calculations when given as input.

### General assumptions 2026

<table data-full-width="false"><thead><tr><th width="317.74993896484375">Name</th><th width="82">Type</th><th width="194.333251953125">Description</th><th width="98.1666259765625">Default</th><th width="98.25018310546875">Notes</th></tr></thead><tbody><tr><td>fixed_gas_price</td><td>float</td><td>From CBS, fixed gas cost.Transporttarief + vast leverlingstarief</td><td>360.98</td><td>In €/year</td></tr><tr><td>variable_gas_price</td><td>float</td><td>From CBS, variable price exc. tax. Variabel leveringstarief contractprijs</td><td>0.5783</td><td>In €/m^3</td></tr><tr><td>energy_tax_gas</td><td>float</td><td>From CBS, energy tax on gas</td><td>0.72680</td><td>In €/m^3</td></tr><tr><td>fixed_electricity_price</td><td>float</td><td>From CBS, fixed electricity price. Transporttarief + vast leveringstarief</td><td>589.82</td><td>In €/year</td></tr><tr><td>variable_electricity_price</td><td>float</td><td>From CBS, variable price exc. tax. Variabel leveringstarief contractprijs</td><td>0.1387</td><td>In €/kWh</td></tr><tr><td>energy_tax_electricity</td><td>float</td><td>From CBS, energy tax on electricity</td><td>0.11085</td><td>In €/kWh</td></tr><tr><td>tax_credit</td><td>float</td><td>From CBS, vermindering energiebelasting</td><td>628.96</td><td>In €/year</td></tr><tr><td>dynamic_purchase_markup</td><td>float</td><td>The markup the supplier charges on top of the electricity market purchase price for a dynamic contract</td><td>0</td><td>In €/kWh</td></tr><tr><td>dynamic_feed_in_markup</td><td>float</td><td>The markup the supplier charges on top of the electricity market sell price for a dynamic contract</td><td>0</td><td>In €/kWh</td></tr><tr><td>fixed_heat_price</td><td>float</td><td>From Vattenvall, tarifs 2025</td><td>760.77</td><td>In €/year</td></tr><tr><td>energy_tax_heat</td><td>float</td><td>Tax on consumed external heat</td><td>0</td><td>In €/GJ</td></tr><tr><td>variable_heat_price</td><td>float</td><td>From Vattenvall, including, rent afleverset</td><td>43.79</td><td>In €/GJ</td></tr><tr><td>feed_in_compensation</td><td>float</td><td>Earnings per kwh fed back in the grid</td><td>0.1331</td><td>In €/kWh</td></tr><tr><td>feed_in_cost</td><td>float</td><td>Cost per kwh fed back in the grid</td><td>0.125</td><td>In €/kWh</td></tr><tr><td>fixed_solar_panel_cost</td><td>float</td><td>Yearly extra charge from electricity supplier if you have solar panels</td><td>0</td><td>In €/year</td></tr><tr><td>netting_percentage</td><td>float</td><td>The fraction of produced electricity that is returned to the grid (and will count towards salderingsregeling.</td><td>0.65</td><td>%</td></tr><tr><td>gas_yearly_price_increase</td><td>float</td><td>Expected percentage increase in gas price</td><td>0.03</td><td>%</td></tr><tr><td>electricity_yearly_price_increase</td><td>float</td><td>Expected percentage increase in electricity price</td><td>0.02</td><td>%</td></tr><tr><td>external_heating_yearly_price_increase</td><td>float</td><td>Expected percentage increase in external heating price</td><td>0.03</td><td>%</td></tr><tr><td>term</td><td>integer</td><td>The term in years used for calculation return on investment</td><td>25</td><td>In year</td></tr><tr><td>discount_rate</td><td>float</td><td>Discount rate (~inflation) used in return on investment calculation</td><td>0.04</td><td>%</td></tr><tr><td>tax_rate</td><td>float</td><td>General VAT</td><td>1.21</td><td>%</td></tr><tr><td>custom_measure_costs</td><td>dict</td><td>TBA</td><td>{}</td><td></td></tr></tbody></table>

#### Input schema

```
"cost_indicators": {
      {
        "name": value
      }}
```

#### Example

```
{
  "postcode": "3024XL",
  "housenumber": 227,
  "houseaddition": "B",
  "cost_indicators": {
    "fixed_gas_price": 337.89,
    "variable_gas_price": 0.6595,
    "energy_tax_gas": 0.69957,
    "fixed_electricity_price": 575.76,
    "variable_electricity_price": 0.1470,
    "energy_tax_electricity": 0.12286,
    "fixed_heat_price": 760.77,
    "energy_tax_heat": 0,
    "variable_heat_price": 43.79,
    "tax_credit": 635.19,
    "feed_in_compensation": 0.1331,
    "feed_in_cost": 0.125,
    "fixed_solar_panel_cost": 0,
    "netting_percentage": 0.65,
    "gas_yearly_price_increase": 0.03,
    "electricity_yearly_price_increase": 0.02,
    "external_heating_yearly_price_increase": 0.03,
    "term": 25,
    "discount_rate": 0.04,
    "tax_rate": 1.21
  }
}
```

### Custom measure costs

<table><thead><tr><th width="82.75">Code</th><th width="407.33349609375">Description</th><th width="85.333251953125">From</th><th width="65.916748046875">To</th><th width="94.25">Unit</th></tr></thead><tbody><tr><td>10001</td><td>Gevelisolatie naar type “Matig”</td><td></td><td>2</td><td>€/m<sup>2</sup></td></tr><tr><td>10002</td><td>Gevelisolatie naar type “Goed”</td><td></td><td>3</td><td>€/m<sup>2</sup></td></tr><tr><td>10003</td><td>Gevelisolatie naar type “Zeer goed”</td><td></td><td>4</td><td>€/m<sup>2</sup></td></tr><tr><td>20002</td><td>Vloerisolatie naar type “Goed”</td><td></td><td>3</td><td>€/m<sup>2</sup></td></tr><tr><td>20003</td><td>Vloerisolatie naar type “Zeer goed”</td><td></td><td>4</td><td>€/m<sup>2</sup></td></tr><tr><td>30002</td><td>Dakisolatie naar type “Goed”</td><td></td><td>3</td><td>€/m<sup>2</sup></td></tr><tr><td>30003</td><td>Dakisolatie naar type “Zeer Goed”</td><td></td><td>4</td><td>€/m<sup>2</sup></td></tr><tr><td>50002</td><td>Glas van type ''Enkel glas'' naar type ''HR++ glas''</td><td>1</td><td>3</td><td>€/m<sup>2</sup></td></tr><tr><td>50003</td><td>Glas van type ''Enkel glas'' naar type ''Drievoudig glas''</td><td>1</td><td>4</td><td>€/m<sup>2</sup></td></tr><tr><td>50102</td><td>Glas van type ''Dubbel glas'' naar type ''HR++ glas''</td><td>2</td><td>3</td><td>€/m<sup>2</sup></td></tr><tr><td>50103</td><td>Glas van type ''Dubbel glas'' naar type ''Drievoudig glas''</td><td>2</td><td>4</td><td>€/m<sup>2</sup></td></tr><tr><td>50203</td><td>Glas of type ''HR++ glas'' naar type ''Drievoudig glas''</td><td>3</td><td>4</td><td>€/m<sup>2</sup></td></tr><tr><td>60003</td><td>Ventilatie naar type ''Decentraal mechanisch''</td><td></td><td>4</td><td>€/unit</td></tr><tr><td>80004</td><td>Installatie van type ''Lokaal gasverw.+geiser'' naar type ''HR-combi''</td><td>1</td><td>4</td><td>€/unit</td></tr><tr><td>80104</td><td>Installatie van type ''VR-ketel+geiser'' naar type ''HR-combi''</td><td>2</td><td>4</td><td>€/unit</td></tr><tr><td>80204</td><td>Installatie van type ''VR-combi'' naar type ''HR-combi''</td><td>3</td><td>4</td><td>€/unit</td></tr><tr><td>80008</td><td>Installatie van type ''Lokaal gasverw.+geiser'' naar type ''WP lucht combi''</td><td>1</td><td>6</td><td>€/unit</td></tr><tr><td>80108</td><td>Installatie van type ''VR-ketel+geiser''  of ''VR-combi'' naar type ''WP lucht combi''</td><td>2, 3</td><td>6</td><td>€/unit</td></tr><tr><td>80408</td><td>Installatie van type ''HR-combi'' of ''HR-combi+zonneboiler'' naar type ''WP<br>lucht combi''</td><td>4, 5</td><td>6</td><td>€/unit</td></tr><tr><td>80030</td><td>Installatie van type ''Lokaal gasverw.+geiser'' naar type ''Hybride warmtepomp''</td><td>1</td><td>8</td><td>€/unit</td></tr><tr><td>80130</td><td>Installatie van type ''VR-ketel+geiser'' of ''VR-combi'' naar type ''Hybride warmtepomp'</td><td>2, 3</td><td>8</td><td>€/unit</td></tr><tr><td>80430</td><td>Installatie van type ''HR-combi'' of ''HR-combi+zonneboiler'' naar type ''Hybride<br>warmtepomp''</td><td>4, 5</td><td>8</td><td>€/unit</td></tr><tr><td>70000</td><td>PV Panelen naar type ''PV Paneel per m2''</td><td></td><td></td><td>€/paneel</td></tr></tbody></table>

#### Input schema

```
"cost_indicators": {
      {
        "custom_measure_costs": {"code":value, 
                                 "code":value
                                 }
      }}
```

#### Example

```
{
  "postcode": "2771DS",
  "housenumber": 87,
  "houseaddition": "",
  "cost_indicators": {
    "custom_measure_costs": {"10002": 41,
                             "20003": 72,
                             "30003": 86,
                             "40003": 86,
                             "60003": 2800,
                             "80408": 11151,
                             "70000": 182
                             }
                      }
}
```


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