Volume –Some theaters are low and squat, making it difficult to suggest the spaciousness or vistas your play may need. 5.1 (Views through a window or over a wall can help.) In other spaces, hanger-like emptiness drowns the actor… That, of course, depends on the actor: in one production, one couple had a fight in the bedroom and seemed to flail in a limitless void; next scene, same bedroom, the next couple folded a bedspread and filled the space. (For the too much volume problem, dropping in a soffit, cornice, or chandelier can help.) Remember that solid and void and volume create shape and form.
Balance – The classic approach to balance in design is symmetry. A drawing of a symmetrical design can be folded in half and match: imagine a colonnade with three equal arches centered on the stage. Symmetrical arrangements are automatically balanced and pleasing, but, because they’re predictable, can be a bit dull. Classical logic also places the large or heavy object at the bottom and the small or light object on top, as a wise child stacks blocks. Symmetry can be suited to classical authors or periods. Mozart maybe or Moliere, the Greeks…
The other type of balance is asymmetrical balance. Now, instead of one side of the stage mirroring the other, imagine center stage as the pivot point of an old-fashioned see-saw. On one side, balance a single, blocky, visually heavy element, on the other, a couple tall, thin, light elements - maybe a bulky fireplace versus tall windows. Japanese prints perfected the asymmetrical.
As with arranging flowers, an odd number helps - a dozen roses look better in a vase if one becomes a boutonnière – so place 3 or 5, not 4 roses or windows. Balanced asymmetry is harder than symmetry, but may arguably better represent the modern world. Maybe Harold Pinter sees the world thus lop-sided?
5.1 As Shakespeare once put it, “Can this cockpit hold the vasty fields of France?”