Open Data vs. Listings: How to Evaluate Property Using Both Sources

Why Compare Open Data with Listings?

For real estate evaluation, it is important to use both open data (historical transactions) and real estate listings. Each source provides its own perspective: open data shows what properties were actually sold for, while listings show what they are currently offered for. By understanding the differences and limitations of both sources, you can get a more accurate property evaluation.

What is Open Data (Market Data)?

Open data or market data are officially registered real estate transactions published in the Land Registry. This data includes information about each completed transaction: address, price, area, transaction date and other parameters. In market data platforms like Hesti, this data is compiled and structured to be easily analyzable. Open data is a reliable source because it reflects actual selling prices, not just asking prices.

What are Real Estate Listings?

Real estate listings are active offers where property owners or agents publish information about properties they want to sell or rent. Listings typically show the asking price, property description, photos and contacts. In various platforms you can find thousands of active listings. It is important to understand that listing prices are often a starting point for negotiations, not the final price.

Why Can Listing Prices Differ from Transaction Prices?

There are several reasons why the price listed in an ad may differ from the actual selling price:

• Negotiation room — sellers often start with a slightly higher price to leave room for negotiations. In practice, the selling price can be 5-10% lower than the price listed in the ad.
• Market dynamics — if the market changes quickly, listing prices may be outdated, while transaction prices reflect the current situation.
• Property condition — the listing may not accurately describe the property condition, which affects the final price.
• Additional costs — sometimes the price listed in the ad does not include all costs, which can affect the final transaction amount.

When Can Open Data Be Higher?

Interestingly, in some cases the price shown in open data may be slightly higher than might be expected when comparing with listings. This can happen in the following scenarios:

• Furniture and interior — if the transaction also includes the purchase of furniture, appliances or interior elements, the total amount will be higher, but this does not apply only to the property.
• Separate elements — sometimes the transaction also includes a basement, parking space, playground or other separate elements that are registered together with the final amount.
• Additional properties — the transaction may include multiple properties or land plots that together make up a higher amount.

Therefore, when analyzing open data, it is important to check whether the transaction includes only the property or also other elements.

How to Evaluate Property Using Both Sources?

To get the most accurate property evaluation, use this approach:

1. Start with open data — search for similar properties that were sold in the last 12-24 months. Look at the average and median price €/m².
2. Compare with listings — search for similar properties in active listings and compare their prices with historical transactions.
3. Consider negotiation room — if the listing price is 10% higher than the average selling price of similar properties, the seller may be ready for negotiations.
4. Check transaction details — investigate whether the transactions shown in open data include only the property or also other elements (furniture, basement, etc.).
5. Use both sources together — combine information from both sources to get a complete market picture.

Practical Example: Apartment in Center

Let's say you are looking for a 2-room apartment in the Center, 50 m². How to use both sources?

Step 1: Open Data Search for similar apartments that were sold in the last 12 months. Let's say you find 10 transactions with an average price of 1200 €/m². This means the average selling price was 60,000 €.

Step 2: Listings Search for similar apartments in active listings. Let's say you find 5 listings with an average price of 1300 €/m² (65,000 €).

Step 3: Analysis Listing prices are approximately 8% higher than actual selling prices. This indicates that:

• Sellers leave room for negotiations
• The market may be slightly hotter than historical transactions show
• A realistic price would be around 62,000-63,000 € (taking into account negotiation room)

Step 4: Detailed Check Check whether historical transactions include additional elements. If a transaction seems too expensive, it may have included furniture or other elements.

Common Mistakes and How to Avoid Them

When analyzing open data and listings, avoid these mistakes:

• Outdated data — do not use transactions older than 24 months, as the market may have changed significantly.
• Incorrect comparison — compare only directly similar properties (same district, series, area, number of rooms).
• Ignoring negotiation room — do not assume that the listing price is the final price; always consider possible negotiation room.
• Insufficient detail — do not check whether the transaction includes only the property or also other elements.
• Using one source — use both open data and listings to get a complete picture.

How Does Hesti Help Compare Open Data with Listings?

The Hesti platform allows you to simultaneously view both open data and real estate listings:

• Data map — view both historical transactions and active listings on a map to compare prices in one area.
• Transaction catalog — browse historical transactions in detail with filters by district, price, date and other parameters.
• Listings catalog — search and filter active real estate listings.
• AI price forecasts — get machine-learning-based market price estimates that take into account both historical transactions and current listings.

This combination allows you to get the most accurate property evaluation and understand the full market picture.

Conclusion

Open data and real estate listings are both important sources for property evaluation. Open data shows what properties were actually sold for, while listings show what they are currently offered for. By understanding that listing prices are often higher (preserving negotiation room), but open data can sometimes be higher (if they include additional elements), you can get a more accurate property evaluation. By using both sources together and analyzing each transaction and listing in detail, you can make informed decisions and avoid overpaying or setting an insufficient price.