Parts of a Front Door Explained

Published April 26, 2022
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Lake Washington Windows

When a person first looks at a home’s front door, it’s hard to imagine the number of parts involved in its construction. Each piece serves a unique purpose for the house to remain safe, welcoming, stylish, and energy-efficient. There are three major components to building a front door:

  1. Door frame
  2. Door unit
  3. Door hardware

Below is a glossary of all the parts of a door and their function in a home’s entryway.

Door Frame Anatomy

The first step in building a front door is constructing the exterior door frame.  This begins with an opening using the wall’s framing.  This is  where the door will reside and ends with the header, sill,  jambs, and trim. When it’s time to choose a new entry door, there are many factors to consider. For a great place to start the process, check out some of the popular front door styles we love. The most important decision is the type of material that you want your door to be made out of.


Brickmold is a type of trim designed to hide the gap between the frame of exterior doors and exterior walls. Brickmold is thicker than most interior casing trim made from wood, aluminum, PVC, fiberglass, or composite materials.

Door Frame

The door frame is the structure attached to the rough opening, which holds the door panel and sidelights. It consists of the header, sill, and two side jambs of wood, aluminum, or steel.

Door Jamb

Door jambs are the vertical components on either side of the door frame. Mounting hinges are installed into one jamb while the other contains the strike plate for the latch.

Door Trim/Casing

The door trim is the decorative pieces placed over door frames to hide the gap between the rough opening, jambs, and header. The casing is a trim used to conceal the frame and wall gap.

Head/header/head jamb

The head or door header, often mistakenly called a “head jamb,” is the horizontal section of the door frame that forms the top of the doorway.

Rough Opening

The rough opening is the opening in a wall that will hold the door frame that consists of standard framing materials built 2” wider and 2” taller than the size of the door unit.


Door sills are the bottom component of the door frame that fastens to the floor. A threshold, made of durable materials to withstand heavy foot traffic, is then placed over the door sill to provide weather protection.

Stop Molding

Stop molding is attached to the interior edge of door frames where the door rests and aligns to prevent it from swinging beyond its closed position.

Door Anatomy

Once built, the door frame is ready for the installation of the door unit. The parts of a door unit include everything from the door panel to the sidelights and all the decorative details surrounding it.

Bore Hole

The bore hole is drilled into the door panel for the lockset hardware.

Dentil Shelf

A dentil shelf is a decorative element of an exterior door usually installed under a panel’s quarter lite and considered a hallmark element of craftsman design.


The doorway is the opening people walk through when the panel is open and is the front door component that most people refer to as the door.

Door Panel

The door panel, also called the door slab, is the component that swings open and closed, which most people would refer to as the door itself. Often, a complete door slab consists of smaller panels set between stiles, rails, and mullions.

Fixed Panel

A fixed panel is the half of a double door which is often held in place by a flush bolt that unlocks to open both door panels.

Glazing / Glass

Glazing is the glass placed in a door panel, sidelight, or transom lite. Glazing typically consists of two glass panes with argon gas injected in between to provide additional insulation.


Grilles are small bars that divide or create the effect of divided lites. Grilles between the glass are permanently installed between panes, while regular grilles are placed over the top of a single pane to create the effect of divided lites.

In-Swing / Out-Swing Door

In-swing doors open toward the home’s interior, requiring pushing to enter from outside the house and pulling to exit. Out-swing doors open to the home’s exterior, requiring pulling to enter from outside and pushing to leave.


Mullions are vertical and horizontal components used to separate sections within a panel, window, or door frame, not to be confused with center stiles or mutins, the small strips of wood used to divide individual panes.


Panels form the primary surface of the door. Some doors consist of a single panel, while others consist of multiple smaller panels set between stiles, rails, and mullions.


Rails are the horizontal segments located within the panel to divide it into sections. A panel with rails usually includes a  top rail, a middle rail, and a bottom rail, while more intricate designs may also include a frieze (or intermediate) rail.

Sidelight (or Sidelites)

Sidelights are tall narrow windows installed on one or both sides of a front door to create a more decorative entryway and provide additional natural lighting. Usually, sidelights are fixed windows, although operable & vented sidelights are available.


Sticking is a decorative edge added to stiles and rails that hold the panels in place.


A stile is a vertical segment located on either side of a door panel. The hinges attach to the hinge stile, and the lockset attaches to the lock stile. Some door units may also include a center stile designed to provide extra support.


The transom is a horizontal beam at the top of a doorway that separates the door from an upper decorative window installed between the transom and header, commonly known as a transom window or transom lite.

Door Hardware Parts

Once the panel is ready for installation, hardware such as hinges, locksets, and weatherstripping will give a front door the functionality required to open, close, lock, and protect against changing weather.


An astragal is a strip of material and weatherstripping covering the seam between exterior double doors, such as front doors and patio doors, to prevent wind and water from entering the house.


A deadbolt is a thick metal locking mechanism that secures the panel to the door jamb when extended. Deadbolts are generally installed separately from the rest of a lockset as they’re considered an additional security measure.

Door Sweep

A door sweep is a form of weather-stripping installed on the bottom of a door panel to seal the gap between the panel and door sill to protect against wind and rain.


A door handle is a mechanism used to operate the door latch, allowing the panel to release from the frame to open and close. Handles come in various forms, including lever handles, thumb latches, and door knob that twist to retract the latch.


Door hinges are the mechanisms that allow the door to swing open and closed, with most front doors having three to four hinges depending on their size. Various hinge styles include a ball bearing hinge, radius hinge, strap hinge, and square hinge.

Hinge Pin

The hinge pin is a metal cylinder inserted between the interlocked hinge pieces attached to the frame and panel to keep the panel in place. Taking the door off its hinges requires removing the hinge pin so the panel can lift away.


The latch is the metal piece that protrudes from the lock stile and secures the panel in a closed position. When the doorknob or handle is turned or pressed, the latch retracts, opening the door.


The lockset is the collection of hardware that includes all the mechanisms required to lock the door, including the handle, locks, latches, strike plate, and any additional hardware needed for assembly.

Mortise/Strike Plate

The mortise plate is a metal plate installed on the door jamb where the latch and deadbolt will lock into place. They add additional strength to the latch, deadbolt, and door panel, which prevents intruders from being able to break through the wooden frame.


A doorstop is a metal cylinder or spring with a padded end attached to the panel or adjacent wall to stop a collision with the wall when the door swings open.

Weather Stripping

Weather stripping is a narrow strip of resilient material like silicone, rubber, or foam that helps seal the gaps between the exterior door panel and its surrounding frame. They are used to prevent draftiness and increase the energy efficiency of exterior doors such as front doors and patio doors.

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Written by Lake Washington Windows

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