An understanding of space, colour, light and pattern, and how they work together to create an effective design. In this article we explore some core interior design principles.


Balance is often found in nature, and is also a central aspect of effective interior design. Balance may be found by the use of contrasting or complementing colours, or by the use of several different elements, such as pattern, layout or texture.

Symmetrical balance is achieved when one side of the design is a mirror image of the other side. There is a distinct dividing line between the two sides. Equal lines, forms, textures or colours can be found on each side of a symmetrical design.

Asymmetrical balance uses different forms, colours and textures to obtain a balance of visual attraction. These opposing compositions on either side of the central axis create equal attraction. For example, mass may be opposed by colour or linear dimension by height.

Sometimes a deliberate lack of balance can be used to suggest spontaneity or to create visual impact.

Perfect symmetry, above, and an example of asymmetrical balance below.


This refers to the direction in which the eye travels and dwells when it first sees a room. This can be affected by a number of aspects, including the visual weight, colour, proximity, line, and layout of the space. For instance, a carpet with a pattern of straight lines leading along a hallway will compel the viewer’s eye to move in the same direction.

Curved lines are stronger when curved toward each other than when curved outward, while indirect focalisation is created by lines curved in the same direction.

Many rooms are designed around a focal point or central feature. In a living room this will often be a fireplace and in a bedroom, the bed. The focal point may be a natural result of the way the room is constructed, so it is decided for the designer before he or she even arrives – an example here would be a huge picture window or a fantastic view.

If a room does not have a natural focal point, the designer will usually introduce one. This might be a fantastic painting or a significant piece of furniture. It is also possible to create a focal space, for instance, a large rug over a natural wood floor, that defines where the furniture is positioned. Often the focal point of the room defines its function – for instance, an office desk, dining table or bed.

Other furniture is positioned in relation to the focal point. In social areas, furniture is often also positioned in a way known as sociopetal – which means in such a way as to encourage conversation. As a general guide, seating should be placed no more than 0.9m (8 ft) apart in order to facilitate conversation. Seats can either face one another or be at a slight angle to each other (for instance, in an L-shape). In situations where, for some reason, you might wish to create the illusion of privacy or where people might feel uncomfortable with the idea that they have to speak to one another (in a gallery or waiting room, for instance) seats are often placed back to back, or far enough away from each other that people do not feel obliged to talk. This is known as sociofugal.

Seats usually require a table within comfortable reach. Coffee tables should be 35 – 40 cm (14 – 16 in) in front of the seating, while end tables should be right next to the arm of the seat. The height of the end table should be as tall as the arm of the chair or sofa.


When a design is harmonious it means that the different elements are working together to give visual cohesion.

Closely related to the idea of harmony is unity. Unity is achieved when every element of the design works together in harmony to express a consistent style. Unity means that all parts of the design, including the furniture, wallcoverings, soft furnishings and floor coverings, fit together. Nothing jars or seems out of place. A room in unity will seem effortlessly well-presented and in tune. To achieve unity the designer must ensure that every element complements the central style or scheme.


This refers to the size of parts of the design in relation to each other and to the design as a whole. A large, dramatic sofa may fit beautifully into a sweeping, open-plan living area but would dwarf a small, traditional lounge. Proportion in interior design often relates to people and their activities, as well as to the way in which each feature of the design relates to other features and to the room or building as a whole. Scale is also a key aspect of proportion.


Rhythm is achieved when elements of a design create a feeling of motion which leads the viewer’s eye through or even beyond the designed area. Tools like colour schemes, line and form can be repeated to attain rhythm in interior design.

In a piece of music the underlying rhythm provides a repetitive, solid base for the other layers of melody. Similarly, in a room, rhythm can provide an important ‘base line’ which holds the room together, creating a sense of continuity or cohesion, and reducing confusion in a complex design. Rhythm may be created by repetition of colour, shape, texture or other design element. Sometimes, however, a lack of rhythm is an important aspect of the design.