Value research is the heart of the comparative method: the systematic collection of data on properties similar to the subject, available on the market or recently transacted.
Where to collect samples
- Online real estate portals.
- Agencies and brokers active in the area.
- Databases of transactions registered at the registry office.
- Direct contact with owners and advertisers.
- Auctions and other forms of sale.
Treating the data (homogenization)
After collection, samples undergo homogenization — adjusting the differences between the researched properties and the subject. The main adjustment variables:
Unit values and range
Values are converted to a unit value (price per m²) that allows direct comparison between properties of different sizes. From the samples, you compute the simple average, the weighted average (weights based on similarity) and the value range (minimum and maximum consistent with the market).
Value variation: it is accepted practice to consider a percentage variation — generally ±15% — around the central value, reflecting the natural dynamics of real estate negotiations.