Sustainability API
Querying the Sustainability API for a Dutch home gives the sustainability measures and Ecovalue market value increase.


With the Sustainability API, Altum AI creates unique insights into sustainability measures, investments, savings and correlated property value consequences ​​for homes in the Netherlands based on the new Energylabel norm NTA 8800. The Sustainability API provides the necessary measures, combined with the investments and savings in Euros and CO2 per measure.

Demo Sustainability API

NTA 8800

The method to come to an estimated energy label has been done by simplifying the input parameters to the most important and influential parameters. In this way, an estimation of the energy label has been made possible for the new norm. In some cases there are installations present in the building not present in the model, or the inner surface area differs largely from the standards. For these cases, it is expected that the model is not accurate in determining the label. Out of 100 cases, we are able to predict the energy label exactly correct in 55 times and in 91 cases only with a marginal difference of one label. This is mostly found in the range of labels C, D and E where the bandwidth of the norm is quite small. The same goes for estimates which differ in two labels, this is mostly found in a difference between C and E where D is has the smallest bandwidth of the energy label classes.

Target energy label

The target energy label to be inputted is now a minimum instead of a maximum. When querying for energy label A, it is possible to get A+ and higher in return depending on the criteria. To mitigate, it is possible to limit the outcome by adding a maximum budget or change the search criteria to the lowest investment costs.

How to use

To be able to deliver sustainability measures, the Ecovalue, the investments, and savings, we need to identify the object based on the zip code and house number. It is then possible to give more input, such as a budget to be able to return the most optimal investments, the desired target energy label to know what needs to be done to reach this label. Enter the current gas usage to give a better estimate and give measures that already have been taken by the homeowner, which needs to exclude in the response. These are not required to generate a response.
Depending on the object, house-type, and input, we generate a response. This response covers the details about the home, such as the address, building type, building year, inner surface area, and if available current energy label. Then we show a full financial statement based on possible measures (depending on if items are locked and if it fits within a specific budget) with the expected investment, total savings, and how many months it takes to earn it back if applicable. Besides that, we calculate the possible Ecovalue home value increase after these measures apply. It also covers the cost of a monthly loan to cover the costs of the investment. We give an estimate of energy and gas usage. After that, we generate a breakdown of the measures in terms of total expenditure and expected yearly savings. Per measure, we show an impact on CO2 reduction in kgs and wattage output. We do not incorporate subsidies into the financing of the measures.

BENG 2.0 norm

Primary fossil energy usage in kWh/m2/year
Smaller or equal to 0
0,01 - 50.00
50.01 - 75.00
75.01 - 105.00
105.01 - 160.00
160.01 - 190.00
190.01 - 250.00
250.01 - 290.00
290.01 - 335.00
335.01 - 380.00
Bigger than 380.00

Customer journey optimization

The Sustainability API uses defaults to give an output based on minimal input. To increase the accuracy of outcome in regards to the current situation of the object you can provide more information. If necessary or desired it is also possible to include or prefer some measures over others to adjust the outcome.
Object & goal
Current situation
Adjusted outcomes
  • Postcode & house number details
  • Target energy label
  • Budget (default: unconstrained)
  • Inner surface area (default: source BAG/Kadaster)
  • Inhabitants (default: 2)
  • Gas usage (default: RVO calculation)
  • Locking of measures (default: ventilation)
  • Output variant (default: medium)
  • Replace boiler possible (default: no)
  • Heat pump allowed (default: yes)
  • Search criteria (default: highest financial ROI)
  • Search options (default: same or worse allowed)
  • Solar panels surface (default: roof maximum covered)


The Ecovalue is the expected market value increase after sustainability measures apply and an energylabel change is present. For example a house which goes from D to A with solar panels, a heat pump and insulation. The Ecovalue takes into account local variety in and whether the label changes to B or A. Changing to energylabel A increases the market value more than changing to B.
The source for calculating the Ecovalue of a home is the so-called Automated Valuation Model (AVM) of Altum AI. This model works with more than 150 variables per house that update in real-time. Consider known variables such as year of construction, inner surface area, volume, parcel area. The Ecovalue is the delta value of a home after specific sustainability measures apply, correlated with an Energy label increase.

Input & input

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