When designing a residential site, one design theme will probably prevail throughout the site. Although the same design theme may be used in the front, sides, and back of the site, it is also possible to use one design theme in the front of the house and a different theme in the back of the house (Figure 10—60). This approach is appropriate for two reasons. First, the designer may wish to create environments of different character. For example, it may be desirable to create a formal setting for the house in the front yard while providing a casual or natural feeling in the backyard. Second, because a person can be in only one area of the site at one time, spaces can have different characters without clashing or conflicting with each other. However, when designing adjacent spaces with different design themes, sensible and comfortable transitions between the two should be considered.
There are times when a designer may choose to create an overall composition that combines two design themes. For instance, Figure 10—61 shows a design that incorporates a rectangular theme for the structured elements (terraces, decks, walkways, and fences), while a curvilinear theme is used for all the planting areas. The straight lines of the rectangular theme reinforce the lines of the house, and the curvilinear theme is associated with the softer character of plant materials. This approach works especially well when the straight lines are placed near the house and the curved lines are located away from the house, establishing a transition from structure to informality as one moves away from the house.
When two similar design themes are combined, the result is not always successful. For instance, a rectangular theme and a modified diagonal theme are so similar to each other that neither will seem to be of major importance when used together. Also,
if the modified diagonal theme is used in a subordinate fashion, the design will most likely be perceived as a rectangular theme with a few corners angled in a weak manner (Figure 10-62).
Another way to combine themes together is to add an accent form to a selected design theme. For example, Figure 10-63 illustrates a rectangular theme with a special circular feature as an accent. This accent could be a fountain or a bed of ground cover with a sculpture displayed in it. Specific shapes furnishing a strong contrast to the overall theme can add interest to a composition.