The second principle of design that should be considered during the preliminary de­sign is unity. Unity is the harmonious relationship among the elements of a design composition. Whereas order establishes the overall organization of a design, unity provides an internal feeling of oneness within the design. The principle of unity influ­ences how the size, shape, color, and texture of any element of a design will appear in the context of other elements of the design. When unity is achieved in a composition, all the elements of the design will feel as if they were meant to go together.

In the previous section, it was described how order is established in trees, ani­mals, and buildings. Using these same examples, unity in a tree can be seen in the sim­ilar size, shape, color, and texture of the leaves. In other words, the similarities among the leaves on a tree give it the appearance of being “one” tree. Hair and skin color are unifying elements on animals; specific building materials and door/window types provide a sense of visual unity in a building.

Unity in landscape design is established using the principles of dominance, rep­etition, interconnection, and unity of three.

Dominance Dominance is created in a design composition by making one element or a group of elements more prominent in comparison with others. The dominant el­ement is an accent or focal point of the composition. A dominant element establishes a sense of unity in that all other elements in the composition appear subordinate or secondary to it. These other elements are visually unified by their common subordi­nation because the differences among these secondary elements seem small in com­parison to their difference with the dominant element.

Without a dominant element in a composition, the eye tends to wander restlessly throughout the composition (left side of Figure 9—12). Here, no one element or portion of the design “holds” the eye. When a focal point is introduced into this same composi­tion, it functions like a visual magnet to pull the eye to it (right side of Figure 9—12).

ComposHion lades a Qcminarrt elemerf attracts

dominant element attention os a focal point.

Figure 9-12

Dominance should be incorporated in a design composition.

An element or group of elements in a design can be made dominant by contrast in size, shape, color, and/or texture (Figure 9—13). In creating a focal point in this man­ner, there are several words of caution. The dominant element should have some qual­ities that are in common with the other elements of the composition so it feels like it is part of the composition. Furthermore, although there may be more than one accent within a design, there should not be so many as to create a chaotic situation where the eye moves continually from one accent to another without rest (Figure 9—14).

The principle of dominance can be applied to landscape design in a number of ways. One way is in the spatial organization of a design. A common fault of many weak designs is the lack of a dominant space (left side of Figure 9—15). Without a dominant space, all the spaces seem rather equal in visual importance and function. A good landscape design typically possesses a hierarchy of spatial sizes with one or more spaces being dominant within the hierarchy. On some sites, a relatively large area of lawn establishes the dominant space (right side of Figure 9—15). On other sites, it is more appropriate for other spaces to be dominant, such as the outdoor entry foyer space (Figure 9—16) and the outdoor living and entertaining space (Figure 9—17).

Dominance can also be created on the residential site using an attractive water feature, a piece of sculpture, a prominent rock, or a spot of light at night. Each can draw the eye’s attention in the landscape. In planting design, dominance can be cre­ated by shade trees, or by attractive plants such as ornamental trees, flowering shrubs, flowers, or other unique plant forms (Figure 9-18).

Repetition A second way unity can be created in a design composition is by repeti­tion. Repetition is the principle of using similar elements or elements with similar characteristics throughout a design composition. Figure 9-19 illustrates the ex­tremes of no repetition and total repetition in a design. As shown on the left side, all

the elements of the composition vary in size, shape, value (tone), and texture. This composition is too complex and consequently lacks unity. The right side shows all el­ements of the composition having similar size, shape, value, and texture. Here, there is a strong sense of visual unity owing to the commonality of all the elements.

No repetition or similarity results in a visually chaotic composition. Each ele­ment is seen as a unique item with no relationship to the other elements. On the other hand, total repetition, although providing unity, often results in monotony. The eye gets bored quickly when there is no variety. Therefore, the ideal approach is to re­peat some elements throughout the design for the sake of unity while others vary for

the purpose of maintaining visual interest (Figure 9—20). There should be a balance between variety and repetition. Unfortunately, there is no formula for providing this balance.

The principle of repetition can be used in residential site design in several ways. First, the number of different elements and materials should be minimized in any area of a design. For example, only one or two pavement materials should be used in an outdoor space because too many pavement materials can be visually disruptive. The designer should also limit the number of different plant materials used in any one area. A design resembling a botanical museum, containing many different types of plants, should be avoided regardless of the temptation to do otherwise.

Having limited the number of elements and materials used in a design, the next step should be to skillfully repeat these throughout the design. When the eye sees the same element or material placed at various locations in the design, visual recall is cre­ated. That is, the eye and mind make a connection between the two locations and mentally link them together. This, in turn, provides unity. One application of this is to use a particular material on the facade of the house and again on walls, fences, or pavement in the landscape (Figure 9—21).

A similar concept can also be applied in planting design. Although only five types of plants plus ground cover have been used in Figure 9—22, they have been woven throughout the composition. Note how the low evergreen shrub material (“A”) has been placed at three locations for visual recall. Also, not every plant has been re­peated. Some plants appear only once in the design for variety and accent. Thus, an attempt is made to strike a balance between repetition and variety.

Interconnection A third way unity can be established in a design composition is by interconnection. Interconnection is the principle whereby various elements or parts of the design are physically linked or tied together. When interconnection is used success­fully, the eye can move smoothly from one element to another without interruption.

There are several ways the principle of interconnection can be applied to resi­dential site design. On the left side of Figure 9—23, the different areas of the design are segmented. The plan lacks unity because it is fragmented into a number of isolated parts that have little or no visual relationship among them. On the right side of Fig­ure 9—23, the same elements of the design have been revised so that the diverse areas of the plan physically connect. The previously isolated parts of the design have now

Figure 9-21

The repetition of brick on the house, low wall, and pavement provides visual unity.

Figure 9-22

Selected plant materials should be repeated throughout a planting area.

been moved together to touch each other and new elements have been introduced to connect the separated ones. The revised plan has a continuity that helps to provide unity. This desirable approach to residential site design reinforces the need to consider the entire site or design area together as one large composition rather than as a num­ber of smaller, separated parts that are merely pieced together.

The same idea can be applied to planting design as well. The left side of Figure 9—24 shows a scattering of isolated plants in a lawn area. Again, this type of arrangement lacks unity and is difficult to maintain. When these same plant materials are placed in a common ground cover or mulch bed as depicted in the right side of Figure 9—24, the eye is able to associate the plants with each other more easily owing to the visual interconnection of the bed on the ground plane.

Interconnection can be appreciated in the third dimension as well. A mass of shrubs, fence, wall, and so on can be used to physically link what otherwise would be separate elements of a landscape composition (Figures 9—25 and 9—26).

Unity of Three The fourth means of achieving unity in a design composition is by unity of three. Whenever three similar elements are grouped together, a sense of unity is almost automatically achieved. Three of a kind, as opposed to two or four of a kind, provides a strong sense of unity. When the eye perceives an even number

in a grouping, there is a tendency to divide it in half (Figure 9—27). A quantity of three is not easily split in half and therefore is seen as one group (Figure 9—28). As a general rule of thumb, it is better to use odd numbers than even numbers of ele­ments in a single composition, although this is not a guideline to be applied thoughtlessly. For example, when there is a large number of plant materials in a composition, such as six, seven, eight, or more, the eye may see this as a group and not be able to detect whether there is an even or odd number. But when there are two, three, four, or five plants in a group, the eye can quickly depict even and odd amounts. However, there are some occasions when an even number of elements ac­tually functions better than an odd number of elements, especially when there is a desire to achieve symmetry.