Measuring guide

Measure brick-to-brick.

Your doors and windows are made to the exact sizes you enter. Follow these steps and your frames will fit first time.

1. 01

   Find the structural opening

   Remove internal trims or plaster beads if needed so you can see brick-to-brick. Measure the masonry, not the existing frame.

2. 02

   Measure the width three times

   Measure at the top, middle and bottom of the opening. Write down the smallest figure.

3. 03

   Measure the height three times

   Measure at the left, centre and right — from the underside of the lintel down to the bottom of the new cill's position. Your overall height must INCLUDE the cill: measure to the lowest point the cill will sit, not the top of the brickwork. Write down the smallest figure.

4. 04

   Deduct your fitting tolerance

   Take 10–15mm off both the width and the overall height (including the cill). This gives room for packers and expanding foam/silicone so the frame fits square.

5. 05

   Check it's square

   Measure both diagonals. If they differ by more than 10mm, deduct from the smallest measurement accordingly.

6. 06

   Remember the cill is part of the height

   Overall heights include the cill — so a 150mm cill means the frame itself is 150mm shorter. Doors sit on the finished floor level — allow for your flooring if it's not yet laid.

You are responsible for the dimensions you supply. If in doubt, ask your installer to survey the opening.