This article analyses the influence of various variables defined in the initial stage of the design of a single-family
dwelling on its energy efficiency. It also studies the possible contribution of a computer tool in this initial phase
to improve energy efficiency. To this end, an experiment has been conducted. The design of detached single-
family dwellings subject to individual specifications was proposed to 49 novice designers on the Projects VII
course at the M´alaga School of Architecture. To assess the contribution of the computer tool, the novice designers
were divided into two groups: the experimental group, which used the computer tool, and the control group,
which did not. Within each group, half of the students were assigned a cold climate zone and the other half a
warm climate zone. The results show that: a) in the cold climate zone, the greater the compactness, the lower the
energy demand; b) in the warm climate zone, the best energy efficiency is achieved by the confluence of several
variables, namely total openings, orientation and (to a lesser extent) compactness; and c) the designs that have
been supported by the tool are more energy efficient. Finally, ten passive design strategies have been identified
for the reduction of energy demand in single-family dwellings based on the interaction of the variables.
