
How to Measure a Window
January 23, 2026
Choosing the Right Colour for Your Bifold Doors
March 16, 2026Why Accurate Measurements Matter
Getting your bifold door measurements right first time saves money, avoids delays, and ensures a draught-free, secure fit. All of our bifold doors are made to measure, so the dimensions you provide go straight to the factory floor.
Tools You’ll Need
- A steel tape measure (at least 5 m)
- A spirit level (1 m minimum)
- A pen and paper — or use our printable measurement sheet
Step 1 — Measure the Width
Measure the structural opening (brick to brick) at three points: top, middle, and bottom. Record the smallest of the three figures — this is your ordering width. Our factory will make micro-adjustments for a precision fit.
Step 2 — Measure the Height
Measure from the top of the opening to the finished floor level (or top of threshold if one is fitted) at three points: left, centre, and right. Again, take the smallest reading as your ordering height.
Step 3 — Check the Opening Is Square
Measure both diagonals. If they differ by more than 10 mm the opening may need building work before the doors are fitted. Our technical team can advise if you’re unsure — just send us your measurements.
Step 4 — Note the Threshold Type
Decide whether you need a low aluminium threshold (ideal for wheelchair access and flush floor transitions) or a standard UPVC threshold. This can be selected during the order process.
Step 5 — Choose Your Configuration
Bifold doors come in 2 to 7 panel configurations that fold left or right. Think about which way you’d like the panels to stack and where you want the traffic door. Our configurator lets you preview every option.
Common Mistakes to Avoid
- Measuring the old frame instead of the structural opening
- Forgetting to account for floor build-up (tiles, underfloor heating, etc.)
- Not checking the opening is plumb and level
If in doubt, drop us a message with photos and your rough measurements. Our team will double-check everything before production begins — it’s all part of the service.

