This opening chapter presents the primary elements of form in the order of their growth from the point to a one-dimensional line, from the line to a two- dimensional plane, and from the plane to a three-dimensional volume. Each element is first considered as a conceptual element, then as a visual element in the vocabulary of architectural design. As conceptual elements, the point, line, plane, and volume are not visible except to the mind’s eye. While they do not actually exist, we nevertheless feel their presence. We can sense a point at the meeting of two lines, a line marking the contour of a plane, a plane enclosing a volume, and the volume of an object that occupies space. When made visible to the eye on paper or in three-dimensional space, these elements become form with characteristics of substance, shape, size, color, and texture. As we experience these forms in our environment, we should be able to perceive in their structure the existence of the primary elements of point, line, plane, and volume. # Point A Point indicates a position in space. Conceptually, it has no length, width, or depth, and is therefore static, centralized, and directionless. As the prime element in the vocabulary of form, a point can serve to mark: • the two ends of a line • the intersection of two lines • the meeting of lines at the corner of a plane or volume • the center of a field Although a point theoretically has neither shape nor form, it begins to make its presence felt when placed within a visual field. At the center of its environment, a point is stable and at rest, organizing surrounding elements about itself and dominating its field. A point has no dimension. To visibly mark a position in space or on the ground plane, a point must be projected vertically into a linear form, as a column, obelisk, or tower. Any such columnar element is seen in plan as a point and therefore retains the visual characteristics of a point. Other point-generated forms that share these same visual attributes are the: - circle - sphere - cylinder Two points describe a line that connects them. Although the points give this line finite length, the line can also be considered a segment of an infinitely longer path. Two points further suggest an axis perpendicular to the line they describe and about which they are symmetrical. Because this axis may be infinite in length, it can be at times more dominant than the described line. In both cases, however, the described line and the perpendicular axis are optically more dominant than the infinite number of lines that may pass through each of the individual points. Two points established in space by columnar elements or centralized forms can define an axis, an ordering device used throughout history to organize building forms and spaces. In plan, two points can denote a gateway signifying passage from one place to another. Extended vertically, the two points define both a plane of entry and an approach perpendicular to it. # Line A point extended becomes a line. Conceptually, a line has length, but no width or depth. Whereas a point is by nature static, a line, in describing the path of a point in motion, is capable of visually expressing direction, movement, and growth. A line is a critical element in the formation of any visual construction. It can serve to: • join, link, support, surround or intersect other visual elements • describe the edges of and give shape to planes • articulate the surfaces of planes Although a line theoretically has only one dimension, it must have some degree of thickness to become visible. It is seen as a line simply because its length dominates its width. The character of a line, whether taut or limp, bold or tentative, graceful or ragged, is determined by our perception of its length–width ratio, its contour, and its degree of continuity. Even the simple repetition of like or similar elements, if continuous enough, can be regarded as a line. This type of line has significant textural qualities. The orientation of a line affects its role in a visual construction. While a vertical line can express a state of equilibrium with the force of gravity, symbolize the human condition, or mark a position in space, a horizontal line can represent stability, the ground plane, the horizon, or a body at rest.  An oblique line is a deviation from the vertical or horizontal. It may be seen as a vertical line falling or a horizontal line rising. In either case, whether it is falling toward a point on the ground plane or rising to a place in the sky, it is dynamic and visually active in its unbalanced state. # Plane A line extended in a direction other than its intrinsic direction becomes a plane. Conceptually, a plane has length and width, but no depth. Shape is the primary identifying characteristic of a plane. It is determined by the contour of the line forming the edges of a plane. Because our perception of shape can be distorted by perspective foreshortening, we see the true shape of a plane only when we view it frontally. The supplementary properties of a plane—its surface color, pattern, and texture—affect its visual weight and stability. In the composition of a visual construction, a plane serves to define the limits or boundaries of a volume. If architecture as a visual art deals specifically with the formation of three- dimensional volumes of mass and space, then the plane should be regarded as a key element in the vocabulary of architectural design. Planes in architecture define three-dimensional volumes of mass and space. The properties of each plane—size, shape, color, texture —as well as their spatial relationship to one another ultimately determine the visual attributes of the form they define and the qualities of the space they enclose In architectural design, we manipulate three generic types of planes: 1. Overhead Plane The overhead plane can be either the roof plane that spans and shelters the interior spaces of a building from the climatic elements, or the ceiling plane that forms the upper enclosing surface of a room. 2. Wall Plane The wall plane, because of its vertical orientation, is active in our normal field of vision and vital to the shaping and enclosure of architectural space. 3. Base Plane The base plane can be either the ground plane that serves as the physical foundation and visual base for building forms, or the floor plane that forms the lower enclosing surface of a room upon which we walk. # Volume A plane extended in a direction other than its intrinsic direction becomes a volume. Conceptually, a volume has three dimensions: length, width, and depth. All volumes can be analyzed and understood to consist of: • points or vertices where several planes come together • lines or edges where two planes meet. • planes or surfaces that define the limits or boundaries of a volume. Form is the primary identifying characteristic of a volume. It is established by the shapes and interrelationships of the planes that describe the boundaries of the volume. As the three-dimensional element in the vocabulary of architectural design, a volume can be either a solid— space displaced by mass—or a void—space contained or enclosed by planes. Plan and Section: Space defined by wall, floor, and ceiling or roof planes. In architecture, a volume can be seen to be either a portion of space contained and defined by wall, floor, and ceiling or roof planes, or a quantity of space displaced by the mass of a building. It is important to perceive this duality, especially when reading orthographic plans, elevations, and sections.