Building performance is an attribute of a building that expresses how well that building carries out its functions. It may also relate to the performance of the building construction process. Categories of building performance are quality (how well the building fulfills its functions), resource savings (how much of a particular resource is needed to fulfill its functions) and workload capacity (how much the building can do). The performance of a building depends on the response of the building to an external load or shock. Building performance plays an important role in architecture, building services engineering, building regulation, architectural engineering and construction management. Furthermore, improving building performance (particularly energy efficiency) is important for addressing climate change, since buildings account for 30% of global energy consumption, resulting in 27% of global greenhouse gas emissions.[1] Prominent building performance aspects are energy efficiency, occupant comfort, indoor air quality and daylighting.