What is a prescriptive approach?
For the building envelope, a prescriptive approach would list the minimum R-value or maximum U-factor requirements for each building component, such as windows, walls, and roofs. For lighting systems, a prescriptive approach would simply list the allowable watts per square foot for various building types. For mechanical systems and equipment, a prescriptive approach would list the minimum required equipment efficiencies. This approach is quick and easy to use, but you may find the approach somewhat restrictive because the requirements typically are based on worst-case assumptions and all requirements must be met exactly as specified.
