Three methods dominate: the comparison method (based on recent comparable sales), the capitalisation method (based on rental yield, for investment and commercial property), and the reconstruction-cost method (rebuild cost minus depreciation, for new or atypical buildings). A good agent picks the one that fits the property.
Professional valuation is not one formula but a choice between three, and knowing which applies tells you a lot about your property. The comparison method is the workhorse for ordinary homes: the agent finds genuinely comparable properties sold nearby in recent months and adjusts for surface, condition, energy rating and location. It works because a healthy market gives plenty of reference points.
The capitalisation method values a property from the income it can generate. You take the achievable annual rent and divide by the market yield for that segment to reach a capital value. It is the right tool for investment flats, apartment blocks and commercial premises, where a buyer is really buying a cash flow. Yields in Wallonia vary widely, from around 4.8% in Namur to 6.1% in Charleroi (source: hexuvium 2026), so the method is sensitive to the yield you plug in.
The reconstruction-cost method estimates what it would cost to rebuild the property today, then subtracts depreciation for age and wear and adds land value. It suits new builds and atypical buildings (a converted chapel, a one-off villa) where comparable sales barely exist. The counter-intuitive result: for a very unusual property, the “cost to rebuild” can be a more honest guide than a thin handful of loosely similar sales.
Most Walloon homes are valued by comparison, but the best figure often triangulates two methods. Which one leads depends on whether you are selling a home, an income stream, or a one-of-a-kind building.
At a glance
| Method | What it measures | Best for |
|---|---|---|
| Comparison | Recent comparable sales nearby | Standard houses and apartments |
| Capitalisation | Rental income divided by market yield | Investment and commercial property |
| Reconstruction cost | Rebuild cost minus depreciation, plus land | New builds and atypical properties |