Reporting renovation work: how does it work?

Renovation work and assessed value

A cadastral income is recorded for all real estate in Belgium. This is a notional income representing the annual net rent you could receive if you were to rent out the property. The amount of this income depends on various factors, such as the number of rooms, the living area, the comfort of the home, and its location. The cadastral income is used to calculate property tax. Although the income is fictitious, it does affect how much tax you pay.

That’s why it’s so important to report renovation work. Many renovations can affect your home’s assessed value. If you report your renovation work, the property tax can be calculated based on the correct amount. If the value of your home increases and you don’t report the renovation work, you risk a fine. Failure to report a renovation can, in fact, be considered tax evasion.

For which renovation projects do you need to report remodeling work?

Now you know why it’s so important to report renovation work, but in what cases are you required to do so? This is mandatory in two situations: when you increase your living space or when you improve the comfort of your home.

Reporting renovation work involving additional living space

The assessed value is partly based on the number of rooms and the living space available in your home. Therefore, if you decide to expand your home, this will affect the assessed value. You must therefore report the renovation work in the following situations:

• When you expand your home by creating additional living space, such as by adding a porch

• When you convert an attic or basement into living spaces, such as creating an extra bedroom

• When installing a carport

Report renovation work for greater comfort

The assessed value also depends on the comfort level of your home. This is determined by various factors, such as the home’s amenities. If you choose to make your home more comfortable, you must report these improvements. This applies to the following situations:

• When you have central heating installed

• When you're building an extra bathroom

For which renovation projects is it not mandatory to report remodeling work?

There are certain home improvements that enhance the comfort of your home but do not need to be reported to the land registry. These are energy-saving upgrades. They do not affect the assessed value of the property and therefore do not increase the property tax you owe. These upgrades include the following:

• Insulating Your Home

• Replace single-pane glass with double-pane glass

• Replace your old boiler with an energy-efficient model

• Have solar panels installed

• Installing a heat pump, micro-cogeneration system, or solar water heater

• Installing thermostatic valves

When do you need to report renovation work?

Renovation work must be reported to the Land Registry in a timely manner to avoid a fine. This means that renovation work must be reported no later than 30 days after the renovation is completed. A Land Registry inspector may then visit your home to inspect the renovation work. Based on this visit, the assessed value will be recalculated.

Where should you report renovation work?

You must report renovation work to the Surveying and Valuation Department. This department is also known as the Land Registry. It has several regional offices, each covering a specific area of Belgium. You must report the renovation work to the regional office serving your municipality. You can do this by filling out a form titled "Reporting Changes – Renovation Work."

Are you planning to carry out renovation work that requires a permit? In that case, it is usually not necessary to also report the renovation work to the Land Registry. Once your permit is approved, the new information will be automatically forwarded to the Land Registry.

Penalty for failing to report a renovation

If you fail to report renovation work when you’re required to, the fines for failing to do so will remain strict in 2025. Fines can reach up to €3,500. The amount depends on the increase in value resulting from the renovation work. You also run the risk of criminal prosecution. That is why reporting renovation work is so important. Be sure to do this in a timely manner when you renovate your home.