To begin preparing a functional diagram, the designer should have a copy of the design program, site analysis, and base sheet. Each of these items will be used to develop functional diagrams. The designer should also have a roll of tracing paper and a supply of soft pencils. The use of drafting equipment (t-squares, triangles, templates, etc.) is not necessary, because everything will be drawn freehand during this step.
During functional diagrams, the designer locates all spaces and elements of the design program for the first time by using freehand diagrammatic symbols. Each space and element listed in the design program should be located on the site when the diagram is complete.
There are a number of design factors that can be dealt with during this phase of design. They are:
1. Size
2. Location
3. Proportion
4. Configuration
5. Internal subdivision
6. Edges
7. Circulation
8. Views
9. Focal points
10. Elevation change
Each of these factors is addressed individually in the following paragraphs, although each should be considered in conjunction with the others in actual practice.
Size
Before a functional diagram can be drawn, the designer should know the approximate sizes of the spaces and elements to be included in the design. In some situations, this information may already have been established in the design program. If size is unknown, the designer should consult references that identify the size of typical functions on a residential site. Some information is illustrated in Table 8—1. The sizes indicated are common standards; nevertheless, they may be adjusted as necessary to satisfy the particular needs of any given situation.
After determining the necessary sizes, sketch each space and element of the design program on a blank sheet of paper. Each should be drawn as a freehand bubble to approximately the correct size and proportion using the same scale as the base sheet. It is sometimes difficult to comprehend the size of scaled spaces when they are described only with numbers. For example, the area “100 square feet” may not mean much by itself. But when this area is graphically expressed as a freehand bubble at a given scale, the designer is able to see more clearly how much space it actually covers in the plan (Figure 8-2).
Once the spaces and elements have been sketched at their approximate scaled sizes, the designer should have a better understanding of where certain uses should be placed on the site. For example, the designer may need to look for especially open or generous areas of the site for spaces that are particularly large. Also, the designer should have a notion of whether or not all spaces and elements of the design program will fit on the site. It may be found that certain spaces or elements just don’t fit. If this happens, then there needs to be a change in the design program after consulting with the clients.
