Receive email notifications by changing your settings.
Click on your picture in the top right corner, go to Preferences and select your notification preferences.
Thank you for contributing to our forum!
Please keep in mind:
1. To only comment on the topic where the discussion is about. Do you have a new question or topic? Please start a new discussion.
2. Be kind to other users!

How to create a Construction year overlay

edited February 16 in Data

On this forum are some topics about visualizing the construction year in an Overlay. With the new Combo Overlay it is possible to do this. Such an overlay can give insight into a neighborhood.

The construction year comes from the BAG (Basisregistratie Adressen en Gebouwen) data and is shown in the General tab of a building. This attribute is also displayed in the CONSTRUCTION FINISH DATE attribute. The construction finish date is the time in milliseconds relative to the (unix) epoch. If a building has a construction year from the BAG, the time in milliseconds from the epoch to the construction year is calculated, therefore it could be a negative number. Since the BAG is a Dutch dataset, the steps below are only for projects of a location in the Netherlands.

The steps to create the Construction year overlay:

  • Add an Average overlay which shows the BAG ID attribute
  • Add the Combo Overlay, in where the CONSTRUCTION FINISH DATE overlay is Grid A en the BAG ID overlay is Grid B.
  • Then add the following formula to convert the construction finish date attribute to a human readable year: MUL(ROUND(ADD(DIV(DIV(A, 86400000), 365.25), 1970)), GT(B, 0))
  • Change the legend to a more readable one for the map.
  • Update the overlay if Auto Update is off.

End result:

Tygron support team

Sign In or Register to comment.