13 Types of Interior Design Terms & Definitions You Need to Know

Andrea Tru
by Andrea Tru

I'm going to be sharing with you some interior design terms and vocabulary you should know if you're into interior design. I will be breaking this glossary of definitions up into 13 different categories. I first want to talk about the very basics, which are interior design categories.

Residential spaces

1. Residential spaces

There are different types of interior spaces that interior designers can design. The most common ones are residential spaces. These spaces are designed for people to live in. Residential spaces can be either single-family homes or multi-family homes.

Single-family home (detached house)

A single-family home, also called a detached house, is a freestanding residential building that accommodates only one family. This type of building does not share any walls with other buildings.

Multi-family home

Unlike single-family homes, which only contain one dwelling unit, multi-family homes contain somewhere from two to four dwelling units. This means that within one building, there could be one, two, three, or four families living within the same building, and because it is one building, the walls between them are shared between units.

Duplex, triplex, and quadplex

If there are only two homes, that is called a duplex. If it is three homes, it's called a triplex, and if it is four homes, that is called a quadplex.

Townhouse (townhome)

Another very common residential type of property is townhomes or townhouses. These types of homes also share the walls between them.

2. Non-residential spaces (commercial or contract spaces)

The other interior space category is non-residential, also called commercial or contract spaces. These types of environments are related to the business world, which means that they are public spaces.

I'm now going to talk about the interior design terms you should know regarding the structural elements within buildings.

Non-residential spaces

3. Walls


A partition, in interior design terms, is a wall.

Curtain wall

A curtain wall is a non-structural exterior wall made of lightweight materials, typically glass or aluminum.

Load-bearing wall vs non-loading-bearing wall

A load-bearing wall is a wall that supports the weight of a building. A non-load-bearing wall is a wall that does not bear any weight and is used to separate rooms.

Staff vs beam

A staff is a vertical framing member that makes up a wall, and a beam is a horizontal member that withstands a vertical load.

4. Windows

Single-pane vs double-pane window

A single-pane window is a window with one layer of glass only, and a double-pane window is a window that has two layers of glass.

Clerestory window

A clerestory window is a window that is placed at the very top of a wall.

Stained glass window

A stained glass window is a window made from colored glass.

Curved window

A curved window wall is a curved window, and it takes up a large space of the wall.

Deep-set window or a window nook

A deep set window or a window nook is a window with a seating area.


A mullion is a vertical beam that divides up a window.

Window sill

A window sill is a flat piece at the base of the window, and it looks like a mini shelf.

Bay window

A bay window is a window made out of three windows, two of which are placed at an angle.

Bow window

A bow window is a window made out of four or five windows that create the type of a curved structure and appearance.

Awning window

An awning window has a hinge at the top of the frame and swings outward from the bottom.

Examples of ceilings

5. Ceilings

Vaulted ceiling

A vaulted ceiling is a ceiling that angles up towards the roof.


A dome is a curved structure shaped as half of a sphere.

Covered ceiling

A covered ceiling consists of a grid framework that creates recessed panels.

Different types of doors

6. Doors


A hinge is a mechanism that allows a door to swing open.


A threshold is a wood piece that is placed under the door.

Door casing

A door casing it's the frame of a door.

French doors

French doors are two doors that swing open, typically made out of MDF, PVC, or even wood.

Lighting fixtures

7. Lighting

Pop light

A pop light is an under-cabinet recessed lighting fixture.


A sconce is a lighting fixture placed on the wall.


A pendant is a lighting fixture suspended from the ceiling.

Cove lighting

Cove lighting creates indirect illumination by hiding the lighting fixture.

Lumens vs watts

Lumens indicate the brightness of a lighting bulb, and watts are the energy a bulb uses.

Stair terminology

8. Stairs

Stair riser

A stair riser is the vertical space between one stair and the other.

Stair tread

A stair tread is the horizontal section of the stair where you step onto it.

Railing vs handrail

A railing is a structure made out of vertical bars which prevent people from falling to lower levels, and the handrail is the section that you hold on to when you're going up or down the stairs. It's very important not to confuse handrail and railing because these terms are sometimes used interchangeably, but they are different.

Bathroom vocabulary

9. Bathroom

Vessel sink

A vessel sink is a sink that sits on top of a countertop.

Under-mount sink

An under-mount sink is a sink installed under the countertop.

Whirlpool tub

A whirlpool tub is fitted with water jets to provide hydro-massage.

Air tub

An air tub is filled with jets of air to deliver air bubbles for massaging.

Woodwork in interior design

10. Woodwork


A baseboard is a piece of wood that hides the gap between the wall and the floor.


Millwork refers to any woodwork that is installed in your home. This would typically be your built-in cabinets and your doors.


Wainscoting is a wood panel design installed on the lower part of the wall.

Crown molding

Crown molding is a decorative piece of wood placed between the ceiling and the wall.

Different room types

11. Room types


An alcove is a small recessed section of a room.


A mudroom is a room located at the entry of the house or very close to the garage, and it is used to store clothes and shoes before entering the home.

Great room

A great room is a large space that combines a dining room or a family room with a living room.

Powder room

A powder room is a bathroom without a shower.


A foyer is an open area at the entrance of a home or building that connects the home entrance with the rest of the interior.

Furniture vocabulary and definitions

12. Furnishings

Murphy bed

A Murphy bed can be stored vertically against a wall or inside a closet.


A rod is a tube your curtains hang from.


An ottoman is an upholstered seat or bench. Some of them have storage, and some of them have legs.

13. Sustainability interior design terms

Life cycle assessment

Life cycle assessment is a process used to determine whether a material is sustainable.

Sick building syndrome

Sick building syndrome is when people experience acute symptoms by spending a lot of time inside a building.


VOCs are volatile organic compounds, and they are not good. They are like toxins contained within some products inside your home, such as paints and stains, and they are super harmful to your environment, so you always want to avoid any product that contains VOCs. Asbestos is a type of mineral used back in the day for the construction industry, and it is no longer used today because it is highly toxic.

Interior design terms

Which interior design terms are new to you? Comment below to share terms not included in this list that you feel are crucial to interior design.

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