The Seven Basic Principles of Interior Design

Interior design is an art form that blends creativity with functionality to transform spaces. One of the main jobs of an interior designer is to create interior environments that protect the health, safety, and welfare of those who are users of the space. But the other major part of our job is to design a space that is beautiful, inviting, and creative. The part of our training we use most when thinking about interior design as an art form goes back to something we learned about in our formal education. These are the seven principles of interior design. In this blog, we’ll dive deeper into the seven principles and how their rules affect our process when designing.


Design Principle #1: Unity


Unity is the principle that refers to the cohesive relationship between all of the design elements within a space. Every paint selection, fabric, furniture piece, and accessory must work together seamlessly to create unity within a design. Achieving unity doesn’t mean everything has to match perfectly; rather, it involves finding a balance between variety and consistency. One way we like to achieve unity is by using consistent color palettes throughout the space. Having elements of color that repeat throughout a design can create a sense of unity throughout even if the spaces are separated by walls!


Design Principle #2: Balance


Balance is the distribution of visual weight in a space. There are three types of balance: symmetrical, asymmetrical, and radial. Each type of balance while technically being different relates to the feeling or sense of visual weight being evenly distributed. We use balance throughout the entire design process, but we put a huge focus on it during the space planning portion of our process.



Think of symmetrical balance like a book. If you open up a book. Each side is visually the same. We love to use symmetrical balance to create built-ins in a living space. While you may decorate each side of a built-in differently, each will carry the same visual weight because the main structure of the built-in was an exact copy, reflected. On the other hand, asymmetrical balance involves distributing visual weight unevenly but still having the overall sense of balance. Each side of a room carries the same visual weight even though the elements that make up each side may look different. We use this when creating living room arrangements. One side may be anchored with a large sofa while the other may have two chairs and a table. Both sides feel balanced with each other but are not exact copies. Radial Balance is when there is a central element in the space and other elements repeat around it, creating a main focal point in the center. We see this most commonly in a dining area with a round dining table. The light fixture above the table may be the main focus but the structure of the dining table and chairs radiate from that center point.


Design Principle #3: Emphasis


Emphasis, also known as focal point, is about creating a visual dominance in a space. The emphasis in a space is meant to draw attention to a certain element to make it stand out from the other elements in the design. A focal point can be anything from a statement piece of furniture to a bold accent wall or a stunning piece of artwork. A lot of times we work with clients to understand if there are any elements of a design that they want to call attention to. For example, if the client has a piece of art that they love, we may make it the emphasis in a room. All of the other elements of the design will be cohesive with the piece, but not take away from the drama or importance we want to give to the piece of art. We could place a brightly colored piece of art in a room with white walls to make the colors stand out. Then we could pull out colors from the piece to use when fluffing up the space with pillows and accessories to make sure the design is still cohesive.


Design Principle #4: Rhythm


Rhythm in interior design is about creating a sense of movement and flow throughout a space. Just like the main beat in a song, rhythm is achieved by having specific design elements repeat throughout a space. Rhythm is closely tied to Unity in the sense that we are repeating a certain design element throughout a space or spaces to tie a design together. This may be through using a specific color, pattern, or piece more than once or in a repetitive way that creates visual interest and harmony within a space. If a song gets off rhythm, everything feels off. This same concept applies to interior design.



Design Principle #5: Contrast


Contrast is all about creating visual interest by combining two vastly different elements in a space. One way contrast has become prevalent in interior design over the past few years has been its use in kitchens. When we design kitchens, it isn’t uncommon for us to use two, sometimes three cabinet colors that are in contrast from one another. Having this difference creates visual stimulation and interest. A kitchen with all the same colored cabinets is beautiful, but by adding a second or third color into the mix, we can step up the design without changing the functionality at all! The outcome is a visually dynamic space that captures attention and creates a memorable impression.



Design Principle #6: Scale and Proportion


Scale and proportion are about the size and relationship of elements within a space. This is another design element that we pay attention to during the space planning. To create a design that feels well-balanced, it is important to understand the size of the room and the furniture that would properly use the given space. Having a large room with an undersized chair would make a room feel empty, but having a small room with a way oversized sectional that overtakes the space would feel cramped. Both leave a person feeling uncomfortable, which is certainly not a feeling designers want their clients to have.  As designers, we are trained to have an eye for scale and proportion to properly plan a space so that all of the design elements work with a room’s size.


Design Principle #7: Functionality


Functionality is arguably the most important principle of interior design and it is what ties aesthetics back to the other job of an interior designer. As a reminder, an interior designer’s job is also to focus on the health, safety, and welfare of individuals in an interior space. If a space is not designed to function in a way that suits the needs of those living in or using a space, then a designer has failed to do their complete job. Understanding the way a client lives or uses their space is one of the best ways to start a design. Once you know their living patterns and needs, you can design a space based on that information. For example, a designer can arrange furniture to create better flow throughout a space, they can come up with creative storage solutions for a cluttered space, or they can even specify certain fabrics or pieces of furniture that would better suit a client’s lifestyle. By prioritizing functionality in your designs, a space will not only look beautiful but also enhance the quality of life for those who inhabit it.



The seven principles of design are the framework for creating a well-designed space. Working with an interior designer ensures that your space will be both well-designed and functional. Elizabeth Erin Designs works with these principles every day in our work to give our clients the greatest outcome. Schedule a 30-minute consultation with us today to get started on your project!