Getting your door measurements right from the start saves time, stress, and potential fitting issues later on.
Whether you’re replacing an existing door or starting from a blank space, this guide takes you through measuring in millimetres with confidence, including helpful advice on clearances, sizing, and bespoke options.
How to Measure the Opening
When replacing a door, always take measurements from the frame rather than the old door itself, as doors can warp or change shape over time.
If you’re working with an empty opening, measure brick-to-brick using a metal tape measure.
Take three width measurements (top, middle, bottom) and three height measurements (left, centre, right), and make sure to note the smallest of each to ensure a snug fit.
Clearances and Finishing Touches
For smooth opening and closing, allow around 3mm of clearance at the top and sides and approximately 9mm at the bottom.
Most new doors include a solid lipping edge, giving your installer flexibility to trim slightly for a perfect finish.
Always check trimming limits from the manufacturer’s guidance to make sure your new door performs exactly as it should.
Standard Sizes and Bespoke Solutions
The majority of UK internal doors come in standard sizes, with 1981 × 762 × 35 mm (6’6” × 2’6”) being the most common. Other regular options include:
- 1981 × 686 × 35 mm (6’6” × 2’3”)
- 1981 × 838 × 35 mm (6’6” × 2’9”)
Fire doors (FD30) are slightly thicker at 44 mm, offering extra protection. If your doorway falls outside these measurements, a bespoke door will provide the most accurate fit and the best overall finish.
A sturdy metal tape measure, a pencil, and a notepad are all that’s required. Before you begin, remove any obstructions and trims to get a clear view of the opening.
Record all measurements in millimetres and take the smallest dimensions for accuracy.
Don’t forget to measure the depth of the frame and rebate to guarantee the perfect alignment for your new door.
If you’d rather leave the measuring to someone who does it every day, Budget Windows’ experts are here to help, and we’ll take care of it as part of our professional service.
LOOKING FOR A NEW REPLACEMENT DOOR?
From French and patio to bi-folding, we offer an incredible variety of doors inlcuding the latest front and back door designs, all of which are made to measure for the perfect fit to your home.
LOOKING FOR A NEW REPLACEMENT DOOR?
From French and patio to bi-folding, we offer an incredible variety of doors inlcuding the latest front and back door designs, all of which are made to measure for the perfect fit to your home.
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