Energy-efficient building design is a multiple-goal, knowledge-based, problem-solving process. Discusses the nature of the design process in an attempt to define the need for a new type of design support tool. A prototype tool has been developed to illustrate the application of the advanced technology known as knowledge-based systems to the computerisation of design guidelines contained in written manuals. Describes the implemented prototype and the characteristics that distinguish this type of tool both from other types of computerised design tools and from the manual design guide tool upon which it is based. An example consultation session is included to illustrate the flow of user/system interaction, the required input, and the design recommendations generated by the tool. The benefits and ease of using knowledge-based tools during early phases of building design to help to optimise energy efficiency in the resulting building are also discussed.

KEYWORDS: expert systems, computer programs, buildings, designing, prototypes, optimisation