The architectural design is considered to be a process in which policy is established. Policy in this respect is the allocation of values in the various areas of the architectural design field. An architectural element is a means to reach certain preconceived purposes. Energy-efficiency is one of the sub-goals to be reached in the design of an architectural artifact.
In each domain or even in a part of a domain an aspect-design can be made. In the durability-domain it is possible to distinguish a constructional design and, as a part of the constructional-design, an energy-design.