The rectangular theme is composed of squares and rectangles that establish 90-degree relationships between all shapes and lines. This theme may be used in either a formal or an informal fashion (Figure 10-44). The rectangular theme is normally oriented parallel to the sides of a house, thus complementing and reinforcing the typical rectangular layout of many houses. For some people, this type of theme may seem to be foreign to the desired pastoral outdoor environment dominated by living and changing plant materials. Although numerous straight lines in a site may take time to get used to, they are nevertheless able to structure pleasing outdoor spaces. Remember, most people live in pleasing indoor spaces consisting of rectangular forms.
When using a rectangular theme in a design, consideration should be given to (1) the variety of sizes, (2) the scale of the forms, and (3) the amount of overlap among the forms. A variety of sizes of squares and/or rectangles should be used in a rectangular theme. This establishes visual interest and a hierarchy of spatial importance within the composition. The more important spaces of the design should have larger and bolder forms, and the less important spaces should have smaller, less prominent forms (Figure 10-45).
The scale of the forms or areas within the composition also needs thought. Too many short lines and small forms (Figure 10-46) will make a design busy, disjointed, and often difficult to maintain.
When overlapping two or more forms in a design, one guideline is to limit the overlap to one-fourth, one-third, or one-half of the dimension of the adjoining shapes (Figure 10—47). This will allow each shape to maintain its individual identity and be an adequate size and configuration for the intended use. Again, this is only a guideline and not a rule.
The rectangular theme is very appropriate to use when developing exterior spaces as extensions of indoor living spaces. This can create a strong relationship between the house and its surrounding site. A rectangular design theme is also appropriate when the site area is narrow (Figure 10—48) because such a theme is able to make efficient use of space, unlike the curvilinear theme discussed previously (see Figure 10—43).
Some individuals feel that a rectangular theme is often too boring or too formal because of the predictability of the right angles. This can happen if the third dimension is not handled appropriately. However, a well-designed rectangular theme, including one organized on a central axis, can be every bit as exciting as any other design theme if the third dimension provides proper enclosure and variety (Figure 10—49). And it should be remembered that plant materials will add natural softness and a bit of irregularity (if they are pruned in a natural fashion) to a rectangular design theme, making it more attractive in actuality than it might appear on paper.
A rectangular theme can be enjoyable to experience if the third dimension provides variety of enclosure.
When considering landform, a rectangular theme, like a circular theme, is best located on either level ground or on sloped ground where the different areas and forms of the design can be terraced in relation to each other.
Two variations of the diagonal theme used on a residential site are the pure diagonal and the modified diagonal.
Pure Diagonal The pure diagonal theme is essentially a rectangular theme turned at an angle in relation to the house (Figure 10—50). Thus, the compositional guidelines for the pure diagonal theme are similar to those for the rectangular theme. Although many angles can be selected for the relation of the diagonals to the house, it is suggested that either a 60-degree or 45-degree orientation be selected. Both of these angles are directly related to the geometry of the circle and the square and help to minimize acute angles.
When the lines of a pure diagonal theme connect to a house, angular spaces may be created that are not totally functional. This situation can be handled in two ways. First is to allow the angular relationships to form between the house and site (left side of Figure 10—51). This is permissible as long as the angular spaces are kept away from doors or other traveled areas and do not create awkward visual or functional relationships. Second, a designer may use transition lines between the house and the diagonal lines in the site (right side of Figure 10-51).
Modified Diagonal The modified diagonal theme is a combination of the rectangular theme and the pure diagonal theme (Figure 10-52). When diagonal emphasis is preferred without the strength of the pure diagonal theme, the modified diagonal theme offers a pleasant combination. This theme can easily be related compositionally to the 90-degree lines of a house yet offers boldness with the angled lines in the site.
There are several advantages and uses for both the pure diagonal theme and the modified diagonal theme. One possible use is on sites where there is a need to emphasize an orientation other than a direct 90-degree relationship with the house and/or property lines. With the facades of most houses in a neighborhood directly facing each other, there is often a desire to establish a different orientation that eliminates a forced view of the neighbors’ houses. This is especially true when the depth of the surrounding yards is very shallow and/or the neighboring houses are rather close. An angled orientation can provide a more desirable view to some other point of interest within or off the site (Figure 10-53).
A diagonal layout is also advantageous for alleviating the perceived narrow dimensions of a small site. Diagonal lines and spaces may actually provide longer
dimensions than possible with lines and spaces that have a 90-degree relationship with the site property lines (Figure 10—54). The result is that the spaces appear larger, giving the site a more spacious feeling. There may also be a desirable view, favorable orientation to the sun, or good exposure to cool summer breezes that calls for a diagonal direction. When it is suitable to emphasize a diagonal orientation, the diagonal theme offers a feasible compositional alternative for reinforcing and enhancing existing site potentials. The landform could be terraced into flat areas to reinforce the straight-line character of diagonal themes.