Measurement Guide

HOW TO MEASURE

How To Measure

The information below is a guideline, but it will not apply to all projects. We can use approximate

dimensions to discuss pricing, but we will need precise dimensions to place an official order.

When it comes to doors there are four different dimensions that are typically referred to, the Brick

Opening/Masonry Opening, Rough Opening, Unit Size, and Slab Size.

We will always need the UNIT SIZE to

build a custom door and

we cannot calculate the UNIT SIZE for you

The person who is installing the

door is always responsible for determining the unit size.

Brick Opening/Masonry Opening • Rough Opening • Unit Size • Door Slab Size

BRICK/MASONRY OPENING OF THE FRONT DOOR

This is applicable to any door which is being installed in an structure made of materials which can’t be

adjusted. It’s not just for Brick or Stonework, it could also apply to Metal, Cement, and more.

This size the largest of the four, and one of the easiest to measure because it doesn’t involve removing any

material. We can narrow down pricing based on the Brick Opening, but we can’t determine the unit size, which

is the dimension you will need to place an ofﬁcial order.

The Brick Opening is measured from the exterior side of the door, side to side and top to bottom.

The Brick Opening is typically about 2-1/2″ wider and 1-1/4” taller than the Unit Size

. Example is 40

″

x 82-

3/4

″

. The recommended

unit size

for this door would be around 37-1/2

″

x 81-1/2

″

which would be a

slab size

around 36

″

x 80

″

TRAINING PORTAL

www.glenviewdoors.com  |  877.379.3667

PAGE 1
www.glenviewdoors.com | 877.379.3667 TRAINING PORTAL HOW TO MEASURE How To Measure The information below is a guideline, but it will not apply to all projects. We can use approximate dimensions to discuss pricing, but we will need precise dimensions to place an official order. When it comes to doors there are four different dimensions that are typically referred to, the Brick Opening/Masonry Opening, Rough Opening, Unit Size, and Slab Size.
PAGE 2
ROUGH OPENING OF THE FRONT DOOR The next size is the Rough Opening size of entry door which the 2nd largest dimension and typically widely talked about when referring to a new construction. The Rough Opening is the space between the two wall studs the door unit will be attached to. The Rough Opening is typically about 1-1/2” wider than the unit size and about a 1” taller. The space that is left over will be used by the installer to shim and square the unit into place. Example 39” x 821/2”.
PAGE 3
DOOR SLAB SIZE The slab size is the size of the door on it’s own without any frame. A typical frame is around 1-1/2” wider and 1-1/2″ taller than the nominal door slab size. Most manufacturers don’t make their standard doors exactly 36″ x 80″, some customers will think they need a custom door because their slab is just shy or proud of standard dimensions (eg 35-1/2″ x 79-1/2″), but that is rarely the case.