What Is the Difference Between Casing and Trim?

Giovanni Valle is a licensed architect and LEED-accredited professional and is certified by the National Council of Architectural Registration Boards (NCARB). He is the author and managing editor of various digital publications, including BuilderSpace, Your Own Architect, and Interiors Place.

When redoing your house, you’ll likely come across terms that you may not have heard before, such as casing and trim – and if you want your house to look its best, you’ll need to understand the difference between these terms.

Casing is a type of trim. Casing tends to refer to the trim around windows and doorways in a home. But trim can also refer to other types of molding, like baseboards or crown molding. Both are important for home design.

Whether you’re working on a DIY home remodeling project or just curious, you’ll want to familiarize yourself with these common, but distinct terms. Read on to learn more.

What Is Trim?

To understand the differences between casing and trim, let’s first take a look at what trim is. Trim covers any type of wood or other material that creates a line in a room. The trim can be on the ceiling, near the floor, or anywhere along the wall that makes sense.

You can choose from different types of trim based on the aesthetics of the room. That way, the room can look more polished without sacrificing the design.

Using trim can make the room feel more finished, and it’s an easy addition to your home. Consider a few popular types of trim and which one is best for a particular room.

Crown Molding

Crown molding is probably one of the most popular types of trim. You can use it where walls and ceilings meet. The trim goes in at a 45-degree angle, so there is a small amount of hollow space behind the trim.

It’s most popular in public rooms in the home, like living rooms and dining rooms. But you can also use it in a bedroom to add some flair to the ceiling. One of the benefits of using it is that you don’t have to worry about the finish behind it.

Unfortunately, it can be hard to cut gap-free angles with crown molding. If you want to use it and make it look good, consider hiring a professional to cut and install the molding.

Baseboard

Baseboards are another common trim that you’ll find in many homes. They’re the opposite of crown molding because they meet the floor and the wall. A baseboard can serve both a practical and aesthetic purpose.

It can cover any gaps between the flooring and the wall, so it can help keep out bugs and other small critters. A baseboard can also create a clear visual differentiation between the wall and floor.

You can use baseboards in any room of the house. However, they can develop gaps, so you may need to replace them occasionally.

Chair Rail

Chair rail trim gets its name from its height, which is about the same as a chair. This type of trim isn’t too common, but it can look good in a dining room. Its original use was to keep chairs from damaging the surrounding walls.

You can still use the trim for that purpose, but you can also use it more for decoration. Typically the chair rail and the wall below it will be one color, and the upper part will be a different color. That can be a great way to add some color to a dining room.

Picture Rail

Picture rail looks like chair rail, but it’s usually higher on the wall. This type of trim is great if you need something to hold the hooks you use to put up pictures. You can move pictures around, and the picture rail is great for that.

It can also help in rooms with tall ceilings by breaking things up. That can help the room look better and less one-dimensional. However, consider its position in relation to windows if you don’t want the two to interfere.

Picture Frame Molding

If you want a more formal look, you can use picture frame molding. It uses four pieces of molding to create what looks like a picture frame. You can use groups of these “frames” to fill a wall in your home.

This molding looks best in dining rooms and other formal spaces, and it’s easy to install. However, it doesn’t do anything functional. If you want to put up pictures, it could affect where you can do that.

What Is Casing?

Casing is yet another type of trim, though it’s different from the previous types. It usually covers trim that goes around doors and windows. Door casings can add more visual appeal and make doorways look better than those without casing.

Consider a few popular types of casing if you want to redo the trim around your doors.

Mitered Casing

Mitered casing has three parts, two for the sides and one for the top. These casings have 45-degree angles so that two pieces meet and fit nicely together. The top piece has the angle on both sides, while the two side pieces have one angled edge each.

Mitered casing is great because it’s versatile. You can make the door casing simple and flat, or you can add a more fancy design. Consider a couple of mitered casing options.

Ripple Effect

A casing with the ripple effect starts at the inside of the door jam and goes outward. It uses multiple layers of different sizes to give the casing more dimension. The ripple effect is an easy option if you want something more interesting but not too complicated.

You will need to cut different pieces of wood, so you may want to hire help. But it’s a great option if you don’t want something too boring or overwhelming. This casing style is also great if you want to base your home design on the Victorian era when this casing was popular.

Colonial Style

Colonial style casings are even more basic than the ripple effect. They combine a one-piece baseboard with back band molding to create a simpler version of the ripple effect style. So you can still add some depth to your door casings without too much extra fluff.

It’s a great option to try if you’re doing the casing yourself. You don’t need to worry about making complex woodcuts, and you can put the casing together. Then, you can make your doorway look smooth and sleek.

Butted Casing

If you don’t want to worry about cutting angles in the casing, consider a butted casing. Instead of using angles, the top piece sits right on the two side pieces. You can cut each of them as rectangles that meet the right dimensions to fit your door.

Then you can set up each side piece so that they’re parallel to each other. After that, you add the top piece on top for a simple and easy finished look.

The top piece is usually wider than the two side pieces. If you have high ceilings, you can make the top piece as thick as you want. You can even add more decorative pieces to it to make the door stand out.

The Main Difference

You can refer to any of these shapes as trim, and you would be correct. However, casing usually refers to the trim around doors and windows and nothing else. Still, you may meet people who use both words interchangeably. If you’re unsure which word to use, you can always use the term trim to be on the safe side.

Final Thoughts

Casing and trim are two common terms you’ll come across when remodeling a home. While some people use the terms to mean the same thing, that’s not always the case. Trim is more all-encompassing, while casing is for door and window openings.