Aard- en nagelvast

In Dutch civil law, an asset qualifies as being fixed by its nature or by nailing where, by reason of its nature or the manner of its attachment (such as by nails, screws or masonry), it is inseparably connected to immovable property and cannot be removed without damage. Examples include walls, floors, fixed installations and built-in equipment.

This classification determines whether an asset is regarded as movable or immovable and is therefore relevant to the transfer of immovable property, the granting of mortgages, enforcement proceedings and insurance. Assets that are fixed by their nature or by nailing automatically pass with the immovable property and cannot be separately pledged or sold.

In practice, the term is frequently used in the context of renovations, leases and disputes concerning what does or does not form part of the immovable property.