Which building rehabilitation category applies to the reconfiguration of a space, such as removing a wall between two rooms?

The appropriate category for the reconfiguration of a space, such as removing a wall between two rooms, is indeed a modification. This term refers specifically to alterations made to an existing structure that change its original layout or function without altering the fundamental use of the building.

In the context of building rehabilitation, modifications can involve changing internal configurations, such as removing walls, adding new partitions, or making structural adjustments that do not involve a complete overhaul of the building's intended use. This can help improve functionality or meet new requirements while still maintaining the original purpose of the space.

Renovation typically involves restoring or improving parts of the building without necessarily changing its structure or layout significantly, while change of use pertains to altering the building's primary function (for example, converting a commercial space into residential). Reconstruction would involve rebuilding parts of the building after damage or in situations where the structure is significantly altered beyond simple modifications. Thus, modification best captures the idea of reconfiguring spaces like the example given.