Plan for the précompte immobilier (Walloon property tax), building insurance, non-recoverable common charges, maintenance, any management fee, and a provision for rental vacancy and unpaid rent. Together these usually consume 25% to 40% of gross rent, which is why net yield sits well below gross.
Owning a rental in Wallonia carries a predictable set of annual costs, and budgeting for them is the difference between a paper yield and a real one. The largest recurring charge is usually the précompte immobilier, the regional property tax. It is calculated from the indexed cadastral income (revenu cadastral) at a base rate, multiplied up by substantial municipal and provincial surcharges (centimes additionnels), so the amount owed is often several times the base figure (wallonie.be).
Insurance is the next essential. Building (fire) cover is standard and, in a co-ownership, part of it flows through the common charges. Those non-recoverable common charges, the share a landlord cannot pass to the tenant, cover the syndic, lifts, shared cleaning and building upkeep, and can be significant in an apartment block.
Then come maintenance and management. Even a sound property needs upkeep, and a prudent owner sets aside a maintenance provision each year. If you delegate letting and management, a management fee applies. Finally, a provision for rental vacancy and unpaid rent recognises that no property is let 100% of the time and that arrears occasionally happen.
The counter-intuitive figure is how much these add up to: commonly 25% to 40% of gross rent, which is exactly why a 5% gross yield can become a 3% net yield (estate-value.be, 2026). Investors who plan only for the mortgage and forget the précompte, charges and rental vacancy consistently overstate their return. A realistic net-yield model prices in every line below.
At a glance
- Précompte immobilier: Walloon property tax on the indexed cadastral income, base rate plus municipal and provincial surcharges (wallonie.be).
- Building (fire) insurance: essential cover, part often within co-ownership charges.
- Non-recoverable common charges: syndic, lifts, shared upkeep in an apartment block.
- Maintenance provision: annual set-aside for repairs and wear.
- Management fee: where letting and management are delegated.
- Rental vacancy and unpaid-rent provision: for empty periods and arrears.
- Rule of thumb: costs of 25% to 40% of gross rent, so net yield sits well below gross (estate-value.be, 2026).