In 2024 I was looking to buy a house, and in my search I was compiling information from many sources such as Kadaster and Funda. Kadaster is the Dutch parcel management agency, and they publish data on prior home sales, as well as estimated house valuations called WOZ. Funda is a unified housing search website that most of the real estate agents (makkelaars) publish their listings on. 

In late 2025, as part of my push to learn Streamlit by doing, I made Huisjager, a tool to compile all this information into standardized and easy to use tables. 

The tool has many features:

• Extract Kadaster Koopsominformatie PDFs into a table
• Maps out the houses found in the Koopsominformatie table
• Has a form for structuring Funda house listings
• Maps house listings from Funda
• Automatically looks up WOZ valuations and plots the WOZ history versus the Funda asking price
• Automatically geocodes addresses using the PDOK Adres API