The designer creates the sets with the minimum of information needed to convey the period of the play and give the necessary space for the particular scene. The 'Gothic' architecture is sufficient to suggest the medieval period of St Joan. Minimum sets can have the advantage of not being difficult to change, hence eliminating long intervals between scenes, but equally they can be a sign of a limited budget.
Although theatre designs are often considered works of art and are sought after by museums and private collectors, their artistic worth or decorative qualities are secondary to whether they 'work' on stage. The success of a set design cannot be judged until it is translated into three dimensions by the set painters or builders.
It is often difficult from a set drawing to see how the design will be realised. The designer usually conveys an impression which is then translated into detailed scale drawings and set models. Some designers build their own set models, others are realised by specialist model makers or set builders.