Jointly owned building: deduction of costs for the professional part

If a self-employed person uses a jointly owned building for professional purposes, the costs and depreciation should not only be limited to the professional part, but subsequently also to his or her share of the property. There is a special administrative tolerance for buildings in the matrimonial property.

Double restriction?

If you use a building for professional purposes, the costs (including depreciation) are deductible. If you use the building only partly for professional purposes, the general costs are of course limited to that professional part. But what is sometimes forgotten is that the deduction must then be limited to your share in the property if you are not the owner, but 'only' a co-owner of the building.


Suppose you, as an employee, are furnishing a study that makes up 5% of your home. You and your partner own the home. If you prove your actual costs and you bring in the depreciation, the depreciation is limited to 5% of your half of the home….

Suppose you and a business partner have a business in an ordinary home. The home is used 100% by both of you for professional purposes… Then you are both entitled to deduct half of the costs. Otherwise the costs would be 200% deductible...

Suppose you and your brother own a house. You have the ground floor, where you run a business, and your brother lives on the floor above, but he has nothing to do with the business... Then it makes sense that the costs related to the home are only half deductible.
And if you do not use that ground floor entirely for professional purposes (for example, you live in the rooms behind the shop), then your share must also be limited to the professional part.

A double restriction? So yes.

Matrimonial property

A marriage creates 3 types of assets: the assets of each of the spouses, plus the common property. You can play with that joint property through a marriage contract: you can limit the joint property or even block it completely. In the latter case we speak of a total separation of goods. The goods are then co-owned either by one or the other partner, or by both partners together. A matrimonial property goes a little further than co-ownership, because then there is a complete mixing of the property.

As it turns out, the tax authorities have always been of the opinion that the double limitation above (occupational part x ownership share) should not be applied if the building in question is a common property of the married couple.

Only the limitation to the professional part then plays a role. So if you run your business as a self-employed person in a building that is part of the matrimonial property, you only have to take into account the limitation to the professional part to determine the deduction.

A parliamentary question confirms … or not

The federal finance minister was asked about an employee who is starting to use part of his home for teleworking. And, as was to be expected, the minister confirms that
A. teleworking entitles you to depreciation of the home, and
B. the double restriction applies.

What he does not confirm is the administrative position that no ownership restriction is applied to buildings that are in matrimonial property.
Should we attach consequences to that? The question that was asked related to a concrete case in which the partners were not married. So they were co-owners. In fact, it was not asked whether the tolerance still existed.

On the other hand, it must be admitted that the administrative tolerance is somewhat dated. Different treatment between married people and cohabitants (whether or not legally) is a discrimination that will not stand up to any court.

The question is therefore whether the minister consciously or unconsciously avoided tolerance for the property in the matrimonial community of property…

General versus specific costs

In conclusion, it is certainly appropriate to clarify that the double limitation only applies to costs that relate to the entire building. The depreciation of the acquisition or manufacturing cost of the building is the most obvious example of this.

Costs that specifically relate to the business part of the building (such as heating, electricity, furnishings, etc.) are of course 100% deductible, because they are also 100% professional. In such case, the restriction in relation to ownership does not apply.