The Essential Principles of Interior Design: A Conclusive Guide

Interior design is about more than choosing a paint color and arranging furniture. It's about creating a fully-realized aesthetic through every individual component of a room.

And if you want to use every part of your new room with purpose to your advantage, you have to understand the basic principles of interior design.

Here, we're breaking down each component in detail and providing a few tips that you can use to apply these principles to your next kitchen, bathroom, or other remodeling project!

Balance

Your design choices have a significant influence on your subconscious. It goes down to the simplest features, like the way that you employ symmetry or balance.

Balance in interior design is all about equalizing the approximate visual weight of objects. This is only achieved by distributing objects from a central axis. This can be real (a fireplace in the center of the room) or imaginary.

There are three kinds of balance:

1. Symmetrical or formal
2. Asymmetrical or informal
3. Radial

Let's take a closer look at each.

Symmetrical/Formal

Traditional interiors often use symmetrical balance. This type of balance splits the room in half between two sides that mirror each other.

The easiest example of this is two chairs on either side of a coffee table or two couches of equal visual weight facing each other across a fireplace.

The human brain loves this kind of design, as our brains often boil down separate pieces of information into a single, cohesive pattern. We love balanced, symmetrical designs because it keeps the required information down to a minimum.

Asymmetrical/Informal

Then, there's an asymmetrical or informal balance.

Asymmetrical design isn't about a total imbalance of the room. Instead, it's about lines, patterns, and visual weights that don't replicate across a room but are, nonetheless, relatively balanced.

This type of design is much more common in modern rooms, as it can make a space more visually interesting and complex.

Let's go back to our chairs and coffee table example. An asymmetrical design would instead call for a sofa facing two chairs across a coffee table.

Radial

Finally, there's radial symmetry, which is when elements radiate around a central focal point.

This form of design involves a large central piece, like a statement chandelier over a dining table with other pieces arranged around it, like dining chairs arranged around a circular dining table.

This style of balance involves a lot of repetition of color, texture, and form, but since it's based around a central point rather than an exact reflection, it gives you much more freedom than a simple symmetrical design.

Emphasis

A key component of balance is knowing how to use emphasis.

We spoke earlier about visual weight, which guides your eye in establishing the focal point of a room and the relative importance of various components of the room.

In interior design, emphasis refers to how you select and arrange objects and furniture in a room. This gives visual priority to one component over the other. It's also vital in making a room visually interesting. If all the furniture in a room has equal visual weight, the eye has no anchor and will find the room boring.

You've likely appreciated emphasis without realizing it, like when you walk into a room and are immediately drawn to the beautiful view from a window. That's because the room emphasizes the view, giving your eye an anchor to rest on.

Unity

However, while a room without emphasis is boring, you do need a clear sense of unity to tie the whole room together.

Unity can refer to two things:

1. Unity, or the repetition of particular elements throughout your design
2. Harmony, or the sense that the elements of your design complement each other

The major difference between professional designers and the average homeowner is that professional designers look at an entire house to create a unified theme connecting every room, rather than creating an individual theme in each room.

This is important because cohesion makes it easier for our brains to break down a room. If you've ever walked into a room and found that it was too much to handle, chances are it lacked cohesion.

You can achieve unity in a number of ways, from a common style of furniture to more subtle elements like repeated shapes, colors, and textures.

For example, let's say you have a beach house and you love coastal design. One way to create unity through the whole house is to use an overall coastal theme and color palette.

Rhythm

We tend to think of rhythm in connection with music, but the truth is, rhythm has just as much to do with interior design as the beat of a drum.

Rhythm is a design principle that encourages your eye to move through a room in an organized way. It engages your eye to provide a sense of cohesiveness and variety all at once.

Imagine a kitchen. Let's say you have a particular pattern or color in tile backsplash. And let's say that you echo that color and pattern in a painting on the wall, or recall the texture of the curtains in the kitchen/dining area in an accent piece or decoration on the kitchen countertop.

This is how you create rhythm--by echoing a pattern, color, shape, or theme throughout a room to guide the eye. We find this pleasing to see because it makes it easy for our mind to process the room as one complete unit.

Space

Space is a fundamental concept in interior design--after all, you're working with three-dimensional space, so you have to understand how to use various components to make the room attractive.

The physical proportions of a room cannot be easily changed, but you can change the way you use the space.

It has to do with positive and negative space. Positive space has stuff in it and negative space is empty. Positive space is the an island or the fixture or an ornate over-the-range fume hood, while negative space is an empty patch of rug placed in the dining area.

If you wanted to break up negative space--like, for example, an empty counter--you could put a decoration on it, like a bowl of fruit.

It might seem pretty basic, but you have to strike a balance between positive and negative space in order to make a space appealing. If you have an imbalanced space, the room will look overcrowded in one section and empty in another. It stresses and distracts your viewer rather than appeal to them.

Line

Lines are one of the easiest ways to guide the eye and create unity (or contrast). If you leave them out, you'll struggle to bring your room together.

Humans prefer clean lines and angles. After all, we build houses, furniture, and objects using precise angles and lines because it's easier for us to construct them that way. Because of this, we've come to expect clean lines in some form or another.

There are three types of lines you could use in design, whether they're sight lines or lines created by furniture or the room itself:

1. Horizontal
2. Vertical
3. Dynamic

Horizontal lines help provide a sense of stability in a room (remember, we walk on flat surfaces every day!) They can also make a room appear wider and longer when used correctly. These are created using tables and other flat surfaces.

Vertical lines can make a room seem taller, and are usually provided by windows, doors, upright walls, and other similar features. Psychologically, they evoke a sense of freedom and strength--after all, without the walls and doors, the room would be completely flat.

Finally, there are dynamic lines, which are zigzag, curved, or diagonal lines. Horizontal and vertical lines naturally occur in a room due to architecture, but dynamic lines serve to make a room more visually exciting. Be careful not to overuse them, though, or dynamic lines will distract a viewer.

Form

Form refers to the physical form of anything three-dimensional. It can cover the room, your furniture, the objects in it, almost anything really.

Because of this, form is easy for the amateur designer to overlook. But it makes a significant difference in how your room is visually interpreted.

Form generally falls into two categories:

1. Natural
2. Geometric

Natural or organic forms resemble forms we might encounter in nature, whereas geometric forms are sharp edges and hard lines more commonly found in man-made objects. A sectional is geometric, while a lamp made to resemble a tree is organic.

Color

Color has a remarkable effect on our mood and perception of a room--and even the smallest difference in the shade can change our interpretation.

White, for example, tends to evoke a sense of cleanliness, simplicity, or brightness, so white kitchen cabinets are a great way to open up a dark kitchen while calling to mind a sense of cleanliness.

However, when overused or used in the wrong context, white can also bring to mind a sense of sterility, blandness, coldness, and isolation.

When you consider color in interior design, ask yourself how you want to feel in a space. Do you want to feel calm? Cool colors, especially blue, are a great choice. Do you want to feel energized, bold, or excited? Warm colors like red and yellow are a great choice.

You should also consider color throughout the whole home. A unified color scheme is one of the easiest ways to create a cohesive design.

Texture

Texture is the tactile surface of an object--like the feel of wood grain on a table or the smooth cool top of a countertop.

The textures you choose (and how the mind interprets them) will change the level of visual interest in a room and your psychological response to a given space.

For example, let's say you have a fluffy, brightly-colored cushion on a couch. That cushion conveys a sense of comfort because your mind can envision the comfort of touching and feeling the cushion. It also provides visual interest by breaking up the uniformity of the couch.

Now let's say that you decorate primarily with metal furnishings using clean lines and sharp edges. That will make your space feel less inviting unless you add other elements to dial back the harshness that the metal evokes.

Pattern

Decorating with a pattern is the fun part that many designers look forward to. It's one of the easiest ways to take basic elements and turn it up a notch.

You can find a pattern in almost anything, from fabric designs to paintings to rugs. But if you want to use a pattern to achieve unity, your best bet it to echo patterns throughout various elements of the room.

For example, if you have a counter top with a subtle wave pattern in the grain of the granite, you can echo that pattern in the curtains or towels in the kitchen.

The key with any pattern is knowing when to be subtle and when to go all in. Otherwise, you'll overwhelm the eye.

Ready to Use the Principles of Interior Design?

If you're looking to apply the principles of interior design to your own home, whether you want to create a great home coffee bar or redo your whole house, you've come to the right place.

We'v designed for our customers in almost every room of the house, from mudrooms to kitchens to bathrooms to master bedrooms. Whatever your idea might be, we're ready to help you bring it to life.

If you'd like to see examples of our work, click here to take a look at our portfolio.