The model compares the home with similar homes sold nearby and the prices buyers really paid, as registered with the Kadaster (Land Registry). From that it calculates the expected sale price and your chance of getting the home at every bid.
Kadaster
Funda and other listing sites
CBSExample: Karel Doormanlaan 378, Hilversum
Each source fills in what the others leave open. An asking price tells you little without the final sale price, and a sale price tells you little without knowing the home.
What buyers paid
The Kadaster is the Dutch Land Registry. In the Netherlands, ownership passes to the buyer at the office of a notary (notaris). After that transfer, every sale is registered with the Kadaster, together with the sale price. That is the amount the buyer really paid, including any amount bid above the asking price. The model learns from these sales, so it works with what homes actually sold for.
Home details
Funda is the main Dutch listing site. From the listing, the model takes what is known about the home: living area and plot size, type, year built, rooms, garden or balcony, its condition and recent renovations. It also takes the asking price and how long the home has been for sale.
Put the asking price next to the sale price and you see how much buyers in the area bid above the asking price.
EP-Online is the national database with every registered energy label in the Netherlands. We take the label and the date it was issued from there, not from the listing. The model takes the label into account, and solar panels too.
Your report also shows how many kWh per m² the home is away from the next label.
Neighbourhood figures
CBS is Statistics Netherlands, the national statistics office. For every district and neighbourhood it records how many people live there, how densely populated it is, what households look like and how many homes are owned or rented. These figures help the model explain why the price per m² is different two streets away.
The figures for your neighbourhood and municipality are in your report too.
A sale from last year happened in a different market than a sale from last month. That is why the model uses the date of sale, the mortgage interest rate, the number of homes for sale and the trend in WOZ values. The WOZ value is the official value the municipality sets for every home each year.
This way the model takes into account whether a sale happened in a tight market or a quiet one.
You can also enter an address. The model looks up the details of the home.
Sold homes in the area that are similar in type, size, year built and location. For each home it weighs hundreds of characteristics. At least five of those sales appear in your report, with address and sale price, so you can check for yourself whether they are similar.
The amount this home will most likely sell for. In the example from Hilversum, that is €361,687, 3.3% above the asking price.
From 10% to 99%. If you bid with an 80% chance, you would have got the home in 8 out of 10 comparable cases. You decide how much risk you take.
At 50% you bid the expected sale price. Every step up costs money and raises your chance.
See the full sample report
Niek specialises in data science and worked on the model for ten months. He started when he was looking for a house himself and had to guess what to bid on every home. Every report carries his name.
With my dream home I had no idea what to bid, and it went to someone else.
Dion makes sure you understand the report without any background in data. Not sure about a number or about your bid? Then you message Niek and Dion themselves on WhatsApp, in English or Dutch.
Dion on LinkedInRead how Biedadviseur.nl started on our about us page.
A model looks at what is recorded in data. A few things you only see at the viewing, or hear from the seller's agent (verkoopmakelaar).
That is why the report gives a range of chances. Which bid you make is your decision. For more help with the rest of your bid, read our tips for bidding on a house.
No. A valuation report (taxatierapport) is made by a certified valuer (taxateur), for example for your mortgage. Our report is bidding advice: it shows what comparable homes sold for and how big your chance is at every bid. If your mortgage lender asks for a valuation, you have one done as well.
The WOZ value, the official value the municipality sets for your home, runs behind the market. The value for 2026 is based on prices on 1 January 2025. The model works with recent sales and uses the trend in the WOZ value as one of its characteristics.
Nobody knows in advance what other buyers will bid. With a chance for each bid, you see how much risk you run at every amount. At 50% you bid the expected sale price. If you really want the home, you pick a higher bid with a bigger chance.
From the same sales the model works with: homes in the area that have already been sold and registered. For each home you see the address, the asking price, the sale price and the date of sale, and on the map where they are. The model also works with many more sales than the five you see.
Then you get your money back. Let us know via WhatsApp on +31 6 13975548 or email info@biedadviseur.nl.
Paste the Funda link and within two minutes you see which bid gives you a chance. One report costs €24.95. You pay securely with iDEAL or credit card, and if you are not satisfied, you get your money back.