Principles of Design: Point, Line, Plane, and Volume

Hold up! If you haven’t yet read the introduction to this series, check it out before reading this post!

Point, line, plane, and volume are the four most basic spatial components to understand. In fact, most of the other design principles we will discuss later in the series are constructed by assembling these foundational elements in different ways or contexts. So, what are they?


Mathematically speaking, a point occupies one single location in space. In practice, a point is often referred to as a “focal point,” or one element that stands out against its background. In a landscape, a focal point may be a sculpture or statue, an eye-catching plant, a boulder or other natural feature, or any number of other things. To emphasize the focal point, its surroundings are usually more muted and uniform. For example, a homogeneous mass of evergreen shrubs surrounding a striking flowering tree makes the tree stand out more than if it were mixed in with a large variety of plants.

The wall pulls away from this forest pansy redbud to emphasize it as a focal point. From the lawn below, the greenery in the planting bed bed contrasts with the dark purple leaves of the tree.


Back to geometry. A line is a “one-dimensional continuous extent of length.” In landscapes, lines can be straight or curved, and they are often found in basic forms like pathways, fences, and walls. Points, such as plants, can also be arranged in straight or curved lines to achieve different effects. For example, straight lines look much more formal, while curved lines achieve a more naturalistic feel. The direction, length, and combination of lines direct the eye across a landscape, making this a really important feature. To develop a robust planting bed, for example, we don’t scatter plants randomly. Most of the time, plants are arranged in lines (or clusters-more on that in a future post). The way we combine and arrange  lines or “drifts” of plants depends on the desired effect and the site conditions, but the outcome is always something more cohesive and less visually confusing than a random explosion of plant material would be.

Lines of contrasting material can also help subtly divide space. For example, a flagstone patio with one area dedicated to grilling may utilize a brick inlay to separate that part of the space from the rest of the patio. Hardscape lines are somewhat restricted by the material we use, but especially with certain mediums, the possibilities are nearly endless.

The edge of the planting bed is parallel to the edge of the pool deck. There is an attractive contrast between the curvilinear line of the planting bed and the rectilinear angles of the patio.


In geometric terms, a plane is a two-dimensional feature with length and height but no depth. In the landscape, planes can be vertical or horizontal (or really anywhere in between). This isn’t just limited to patios and walls, though. Planes may be solid, but they may also be permeable. Oftentimes, lines can be identified and extruded into planes. For example, a line of trees create a permeable plane with their trunks and canopies. In the line example I mentioned above with a brick inlay separating two separate uses of a patio, you may subconsciously perceive a plane rising up from the brick to separate the two spaces like a wall. Horizontal planes may also be found overhead, like in a pergola or under the canopy of a tall tree with strongly horizontal branching.

The low wall here cuts through the dense liriope, creating an imaginary vertical plane that visually separates the upper and lower levels of the lawn.


A geometric volume consists of height, width, and depth. It’s easy to imagine a cube that has defined sides and contains a volume. The interesting thing is, for our brain to perceive a spatial volume, the “walls” (or planes) enclosing the volume do not have to be complete. In fact, entire planes can be merely implied and still create a strong sense of volumetric space. Consider a clearing in the woods, for example. It has a ground plane, but all the vertical planes are merely composed of scattered trees. At home, an awning over a patio creates a volumetric space beneath without any vertical separation between what is under the awning and what is beyond.

The walls of these two buildings create a strong volumetric space between them. When one crosses into the space, it feels like an outdoor room of sorts.

I hope you found these explanations and examples helpful! Check out the next post in this series to learn about scale, enclosure, symmetry/asymmetry, and axis.

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