24 The Basics The need for a measured survey It is important when designing an interior, particularly one that involves complex subdivision of an existing space, to know the exact dimensions of that space because decisions about the location of new elements inevitably depend on the particularities of the original structure. While drawings of existing buildings may frequently be found and referred to, there are some for which no records exist, and others for which the drawings do not inspire confidence in their own accuracy. In such cases it therefore becomes necessary to carry out a measured survey and to produce an accurate version of plans, sections and significant details. Even for recently constructed buildings it is worth checking the accuracy of dimensions on drawings because variations and discrepancies almost inevitably occur, and go unrecorded, during the building process. A very small discrepancy can often cause problems and embarrassment. When no drawings exist it is normal to draw a plan on site, usually by hand, and good practice to record