Design Elements and Principles of Interior Decorating

Design Elements and Principles of Interior Decorating. Interior designers use design elements and principles to develop interiors that are functional, interesting and aesthetically pleasing. Using the seven design elements as the building blocks of any design, they apply the principles as rules or guidelines to bring everything together. Understanding both the elements and principles is key to a successful design, although the designer may then choose to step outside these boundaries.

A monochromatic color scheme creates unity and harmony.

Design Elements

The seven elements of design are constant throughout the visual arts fields. They are the building blocks of any design. Line is created with a pen on paper or when two edges meet. Shape is enclosed by a line and may be geometric or organic. All lines have direction, either horizontal, vertical or diagonal. The relationship of one area to another is size. Texture is the surface quality of a shape, either physical or visual. Color and value are directly related. Color is the hue of any item, and value is the lightness or darkness of the color.

Design Principles

The principles of interior design are the ways in which the designer arranges the elements. The key principle is unity, in which the house is treated as one space, with a common design theme. Balance distributes the visual weight of all items within a room equally, with no part of the room appearing to be more important than any other. Linked to this is the focal point, a dominant feature of the room that draws attention, yet still must be in balance with the rest. Rhythm is the repetition of a design element, whether a shape, a texture or a color. The two design principles of scale and proportion each deal with size and shape. Scale refers to the size of one object in comparison to another, and proportion is the ratio of one design element to another. In interior design, color is a principle as well as an element and is used alongside the principle of details. Colors affect our moods and emotions, while details add continual interest to an interior.

Putting Them Together

Applying the design principles to the design elements creates a harmonious and interesting room. Unity can be achieved through the use of related colors, perhaps analogous ones next to each other on the color wheel. Rhythm and repetition through similar shapes in different sizes add energy to an interior while creating interest through variety. Balance also adds to the sense of harmony. Designers achieve symmetrical balance by placing similar objects in the same positions on either sides of a room feature. Asymmetrical balance is more contemporary, with dissimilar items of equal visual weight balanced in the room. Designers play with scale in relation to objects or to the patterns in a room's textiles.

Other Considerations

Although not design principles as such, contemporary designers include considerations of inclusive design and sustainable design in their work. Inclusive design considers people of different physical abilities, whether the ability is permanently altered by physical challenges or age, or whether it's temporary -- perhaps a mother with a child in a stroller or someone carrying heavy parcels. Sustainable design is concerned with using eco-friendly products that do not harm people or the planet in their manufacture and use. In addition, sustainable designers develop interiors that will last for years, with minimal attention.


  • John Lovett; Design and Color -- The Elements of Design; John Lovett; 1999
  • "The Fundamentals of Interior Design"; Simon Dodsworth; 2009
  • "The Language of Interior Design"; Alexa Hampton; 2010