1. The area of a room or building that can actually be used for its intended purpose, excluding walls, pillars, and other structural elements
The apartment has 80 square meters of usable space.
O apartamento tem 80 metros quadrados de espaço útil.
2. In real estate and construction, the net floor area that is available for occupancy or use
The office building offers 5,000 square meters of usable space per floor.
O edifício comercial oferece 5.000 metros quadrados de espaço útil por andar.