The plan

Plans are simply maps, a vertical bird’s-eye view of a space. As described earlier, they are drawn to scale and therefore show a proportionally accurate representation of the space and associated walls without the linear perspective that we usually experience when viewing an object. Plans generally try to show no more than the extent of one floor or level within a building, and may only show a single room. Separate plans will show other floors or levels. They show detail within the room that can be easily drawn at scale, and many details are coded into symbols that should be easily recognisable to anyone with a little experience of reading plans. The convention is to show on plan all detail that would be visible if the space was cut horizontally at one meter above the floor level, with the top section removed. All structure and objects that are wholly or partially below this level are shown on the plan drawing in their entirety. For example, a two-meter-high cabinet that sits on the floor is drawn as if viewed whole from above, and not as if it has been cut in half horizontally by the one-meter cut. Objects that are wholly above one-meter level may be shown on the plan, but will be delineated in a different style of line to objects below the one-meter level to aid the legibility of the drawing (usually a broken or ‘dashed’ line).

The one-meter cut is not, however, absolute; common sense should prevail when deciding what is and what is not shown in the plan. For example, it would be unreasonable and misleading to omit windows from a plan just because the windowsill was at a height of 1100 mm (1.1 m) above floor level. It would be just as inappropriate, though, to include clerestory-style windows that were, for example, 600 mm (0.6 m) tall, and which were positioned directly below ceiling level. You should take care to show everything that you think appropriate; however, you shouldn’t expect that the plan by itself can tell the whole story. When two-dimensional drawings are used to describe three-dimensional space, a combination of plan (representing the horizontal plane) and elevations and/or sections (representing the vertical plane) will be used to portray all the features of that space, and they must always be read concurrently.

Drafting (the process of drawing) can employ different conventions of line weight and style to try and convey information; wider lines can be used to delineate structure, and lines can be softened by freehand drawing to represent upholstered furniture, for example. Annotations can also be added to drawings to highlight features that would not otherwise be entirely clear. North points are shown to aid orientation and drawings are carefully titled (for example, plan or east elevation) to instantly identify them. These small points are important; carefully crafted and easily legible drawings promote confidence and convey a sense of professionalism to your colleagues and clients.

Plans have an important role to play in architecture and interior design in that they are usually the first tool used during space planning. However, in the same way that plans should not be read in isolation, the planning process must work in the vertical as well as the horizontal. A study of plans that show furniture layouts and structural elements will soon show that plans in themselves can be drawn entirely correctly but can still be misleading in their representation of space. The process of space planning must consider the impact of the vertical almost as soon as work on the horizontal plan is begun, and for that it is necessary to draw elevations and / or sections.

This survey drawing for a flat in London shows a floor plan and an elevation of one of the walls. Note the title block, showing all the relevant information such as scale and date of drafting.

This elevation drawing shows part of the bar area of a hotel in Bangalore, India. The rendering shows material finishes and proposed lighting effects, and figures have been added to animate the drawing of what should in real life be a bustling and lively space.