Replacing the entrance door is a simple method to make a stark difference in the visual attractiveness of your property. It's simple to replace your front door or select one for a building project, but it helps to be familiar with the appropriate terminology.

There are many different types, designs, and styles of doors for buildings. Every door and door frame has the same essential construction components. Stiles, rails, and panels are the key and crucial parts of a standard door found in buildings.

There are various other components that you might not be familiar with. So you can easily communicate with construction professionals about installing or replacing windows, patio doors, or front doors, I'll share a guide to know the different parts of a door!

About Door Frames

A door frame is the horizontal and vertical pieces that surround the door and are fastened to the wall. Also known as the "Door sash," It is the skeleton or structure that holds onto the door.

Sill, jamb, mulls and head are all door frame components. But of course, the door frame isn't just a border that holds the door in place; it also adds to the door's visual appeal. Commonly used in residential construction, wood was the primary material for door frames.

But now, you can get many alternatives, such as aluminum, granite, fiberglass, WPC, and composites, to match the design of the rest of your home. The size of a door frame will largely depend on how big the doorway is. The price of a door frame might vary greatly depending on its dimensions. The larger the item, the more it will cost.

Parts of a Door Frame

Several components make up a door frame, and all serve an essential purpose. The parts of a door frame include:

1. Door Jamb

The door jams are the inside faces of a doorframe. The French term “Jambe” is the origin of the word "jamb," which directly translates to "leg." Thus, many also refer to door jambs as the "legs" of a door.

On either side of a door, there are two jambs: one holds the mounting hinges, and the other has the striking plate for the latching. The only components referred to as jambs are the two pieces on the sides of a doorframe.

2. Header or Head

Many mistakenly refer to the header of a door frame as the "top jamb." However, "head" or "header" refers to a door's topmost section.

It's a crucial component of the door frame, much like the jambs. It is an entirely different door component than a door jamb because it's on the top rather than the side.

3. Casing

Door casings, also known as door linings, consist of a door frame's head, sill, and jambs. It's just another way of talking about the structure that holds the door. A casing or lining is one way to cover up the bumps where a door frame meets a wall.

4. Sill

The sills of a door are its lowest frame part. They're the door's finishing touch before it's nailed to the ground. Only external doors—those leading outside or to garages—have sills.

5. Threshold

A threshold is a space between the door sill and the room floor. It's a piece of decor that can be as basic or complex as your tastes demand.

The threshold must be sturdy and of good quality to resist the weight and pressure of passing feet. It typically only comes with exterior doors.

6. Sidelights

Tall, narrow windows that can be located on either side of a door are called sidelights. You can install sidelights to brighten up entryways, enhance visibility, and provide a better first impression.

7. Stop Moulding

The decorative molding lines the inside of a door's stiles and rails, keeping the door from swinging inward.

Rebutted jambs, which are door jambs with different sections, serve the same function. In such cases, a doorstop would be unnecessary.

8. Transom

It is an ornamental piece that we can find over a door. If the piece includes glass, it can be called a transom window.

9. Door Trim

It's a decorative piece nailed above the door frame to hide the transition from the jambs and header to the raw opening. Without it, there would be a noticeable space between the door and the wall.

10. Mullion

A mullion is a connection between two discrete units (or mull). A mullion is a window treatment that spans the space between a door's frame and a sidelight, transom, or other decorative glass inserts.

11. Brick Mould

It's decorative molding that goes around outside a door and hides the space where the frame meets the wall. It is more thick than standard home paneling. The brick mold uses different materials, including wood, aluminum, polyvinyl chloride (PVC), fiberglass, or a composite.

12. Weatherstripping

A weatherstrip is a thin piece of rubber, foam, or silicone that fills the space between a door's frame and its panel when you close the door.

13. Panel

It is the central portion of the door and swings back and forth, covering the center of the door. Different door designs may feature one or more panels.

14. Rough Opening

The doorframe is located inside the wall's rough opening. Wedge shims hold the door frame in place once it has been fastened into the space.

15. Rail

Door panels have these thin horizontal pieces called rails. A door has three rails: a top rail, a bottom rail, and a lock rail at the door's center.

16. Stile

Stile is the little, vertical portion of a door panel on either side. Both the lock stile and the hinge stile serve to secure the door. Stiles frame the door panels.

17. Astragal

In a double-door configuration, the astragal is the vertical member that connects the sill with the head.

Hardware Parts of a Door

The term "lockset" describes the collection of components—locks, handles, latches, strike plates, etc.—that make up the hardware that secures a door. Handlesets and hardware are two more names for locksets. The essential hardware parts of a door include:

1. Hinge

This piece of hardware allows the door to slide open and closed. Doors of standard size typically have three hinges; however, oversized doors may have more.

2. Strike Plate

It's a metal attachment that goes into the lock jamb and keeps the latch in place. The latch engages the strike plate when we slam the door shut. This part prevents the latch from damaging the door jamb.

3. Door Handle or Doorknob

A door handle, or doorknob, is a piece of hardware we use to unlock a door. You can open a door with a handle can by pressing down on it. On the other hand, you open a door with a doorknob by turning the knob.

4. Latch

A door latch is a bar or rod made of metal that extends from the edge of the door panel into the frame to hold it firmly in place. It moves back when the door handle is turned, allowing access.

5. Borehole

A door's borehole is the hole drilled into it to accommodate a lockset.

6. Deadbolt

It's an essential component of the locking mechanism, although it's missing from some doors. Like a latch, it provides further protection. It usually has a different mounting hole because it is separated from the handle setup. You can turn the key, which forces the bolt into the mortise, preventing the door from swinging open.

7. Mortise Plate

A door jamb has a mortise plate next to the latch or deadbolt. The latch or deadbolt goes into the mortise plate when the door is closed. It makes latches, deadbolts, and door panels more durable, which helps deter burglaries.

8. Thumb turn

A thumb turn allows a door to be opened and closed electrically from inside a building. It also allows you to open a door mechanically with a key from the outside.

9. Escutcheon

Escutcheons are ornamental plates installed around door knobs, levers, and lock cylinders to prevent damage to the panel's finish.


If you are starting a project to replace or build a door and are confused by the technical jargon, this write-up should have cleared everything up by now! Doors are much more complex than they seem. And it is a must for every craftsman to have an in-depth idea of their parts before working with them.

January 13, 2023 — Della Wang