The next step of the design process, preliminary design, converts the loose freehand bubbles and diagrammatic symbols of the functional diagrams into outdoor rooms that have general shapes and character. The result is an illustrative preliminary plan that can be presented to the clients for their review. There are three important aspects of preliminary design that are considered simultaneously to create the preliminary design:
• Design principles
• Form composition
• Spatial composition
Design Principles. Design principles are aesthetic guidelines that help the designer create a visually pleasing design solution. They aid the designer in making aesthetic judgments about the overall design layout as well as the composition of design elements such as plant materials, walls, and pavement patterns. The three design principles covered in this text are order, unity, and rhythm. Order is the overall framework or visual structure of the design. Unity is the visual relationship among the individual elements within the design. Rhythm concerns itself with the factors of time and movement. All three of these design principles are considered together when preparing the preliminary design. Chapter 9 explains each of the design principles and their application in residential site design.
Form Composition. Another key aspect of preliminary design is form composition. This step establishes specific shapes for all the spaces and elements developed in the functional diagram phase (Figure 4—6). For example, a bubble that represents an outside living space on the functional diagram is now given a definite form that may be composed of a series of specific shapes. Similarly, the edge of a lawn area is drawn with a definite line, such as an attractive curve. This development of forms establishes a visual theme, which furnishes an overall sense of order in the design. During form composition, the designer needs to consider the layout of the functional diagram as well as the appearance and geometry of forms. Form composition is elaborated on in Chapter 10.
Spatial Composition. To develop three-dimensional outdoor rooms, the designer uses grading (landform), plant materials, walls, fences, and overhead structures to
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Form composition study.
define the three planes of spatial enclosure. This spatial composition must consider the height and volume relationships among the various design elements to create a design that is practical and pleasing to the eye. Spatial composition is discussed more in Chapter 11. Preliminary design concludes by drawing the preliminary plan (Figure 4—7), which is then presented to the clients for their review.