What is Casing?

Casing is a type of trim used around doors and windows to cover the gap between the wall and the frame.


In interior design, casing plays a crucial role in the finishing touches of a room. This type of trim, which frames door and window openings, serves both a functional and aesthetic purpose. Functionally, casing covers the gap that exists between the wall and the frame of a door or window. This not only ensures a smooth transition from the wall to the frame but also hides any imperfections or rough edges that might be present, contributing to a polished look.

From an aesthetic perspective, casing can greatly influence the style and character of a room. Available in a variety of designs, materials, and finishes, casings can be selected to complement the interior design theme of a space. Whether you're aiming for a modern, minimalist look or prefer a more ornate, classical aesthetic, there's a casing style to match. Moreover, the details of the casing, such as its profile, width, and finish, can add depth and texture to walls, enhancing the overall visual interest of a room.


Casing is commonly used in residential and commercial interiors. In a home, you might find intricate wood casings around the doors and windows of a traditional living room, or simple, clean-lined casings in a contemporary kitchen. In commercial settings, casings are often used to create a welcoming and professional appearance, such as in hotel lobbies or office entrances.


  • Can casing be used on both interior and exterior doors and windows?

    Yes, casing can be used on both interior and exterior doors and windows, though materials and styles may vary depending on the location and desired aesthetic effect.

  • Do I need to match the casing with other trim in the room?

    While it's not a strict requirement, matching the casing with other trim in a room, such as baseboards, crown molding, and chair rails, can create a cohesive and harmonious look.

  • How do I choose the right casing for my room?

    Consider the overall interior design theme of your space, the visual weight you want the casing to carry, and the compatibility with existing trim. Look for styles that complement your room's aesthetic and decide whether you want the casing to be a subtle accent or a bold statement piece.

Practical Application

When selecting casing for your doors and windows, take into account the overall design style of your room. Choose a material and finish that complements your interior, and consider the size of the casing in relation to the door or window it frames, as well as the room's ceiling height. Installing casing requires precision, so it may be best to hire a professional if you're not confident in your DIY skills. Additionally, think creatively about how you can utilize casing to enhance your room's style and character.