Figuring out the correct measurement for your entrance system can be a challenge sometimes. But first it is important to what components go on an entrance system and then you can determine what the size each of the parts will be need to be to fit around your door.
Click this link to download a guide to better understand each part of an Entrance System:
Entrance System Guide
Dimension “A” – Pilaster Width: These are the vertical components to the entrance system and act as half columns that go to the left and the right of the door. They are available in fluted, plain, and recessed panel and have varying widths and heights depending on the needs of the entrance system
Dimension “B” – Crosshead Bottom Width: This is the Horizontal piece that goes right above the door and above the two pilasters to the left and right of the
door. This width ALWAYS needs to be equal to or wider than the width of the door and the two pilasters. A small ¼” reveal is recommended but can be bigger.
Dimension “C” – Pediment Bottom Width: This is an added feature to the top of crosshead. This dimension needs to be a minimum of 5” wider than the “B” dimension of in order to properly fit on top of the crosshead.
Dimension “D” – Door width: This is width of the door plus any additional material that will be surrounded by the entrance system. This will include a brick mold trim if you elect not to remove and replace with the pilasters.
Step 1: Measure the Door Height. This will determine what length pilasters you will need to order. Standard sizes such as 90”, 108” and an adjustable pilaster are typically available in varying widths. A 14” plinth is made with each size and therefore the pilaster can be cut down onsite to accommodate most heights. For example, if your door height is 100” then order the 108” pilaster and cut the plinth down 8” to achieve the 100” height.
Step 2: Measure the width of the door plus any brick molding that surrounds your opening. This will determine the “D” dimension and then you will be able to figure out what pilaster and crosshead will be needed.
Step 3: Select your pilaster type. Choose a Plain, Fluted, or a Recessed Panel style and then see what widths and heights are available in each style. This will let you determine the width of the crosshead above.
Step 4: Select your crosshead type and pediment (if applicable). Choose the width of the crosshead is as simple as adding the door width (Dimension “D”) plus the width of each of the pilasters (Dimension “A” x 2). This will give you what the bottom dimension of the crosshead will be needed to cover the door opening and the two pilasters. A pediment can be added on top if the sizing is permitted. If a pediment is unavailable you can adjust the pilaster widths (wither wider or narrower) to help achieve the specific width.