Made to Measure Fire Doors: The Ordering Process

Standard fire doors are manufactured to a set range of sizes — typically 1981mm x 762mm or 1981mm x 838mm for single leaves, with FD60 doors available in slightly different dimensions due to their thicker construction. In new builds, structural openings are designed around these standard sizes. But in refurbishment, conversion, and heritage projects, the openings rarely cooperate. That is where made-to-measure fire doors come in, manufactured to the exact dimensions required for each individual opening.

How the Process Works

The ordering process begins with accurate measurement of the structural opening. This is not the same as measuring an existing door — you need the clear dimensions of the opening in the wall, minus the frame and the required gaps. Measure the width at three points (top, middle, bottom) and the height at three points (left, centre, right), and use the smallest measurement in each case. If the walls are not plumb or the opening is out of square by more than 5mm, note this on the order — the manufacturer may need to adjust the door or frame to compensate.

You will also need to specify the door construction (FD30 or FD60), the facing material (paint grade, oak veneer, etc.), the hanging side (left or right as viewed from the pull side), and the positions of any glazed apertures. If the door will receive a lock, latch, or viewer, provide the positions and types so the manufacturer can pre-machine them. Any site machining on a made-to-measure fire door risks voiding its certification, so it is always better to specify hardware positions upfront.

Lead Times and Costs

Made-to-measure fire doors typically take between 4 and 8 weeks to manufacture, depending on the complexity and the manufacturer's order book. Glazed doors and FD60 doors tend to sit at the longer end of that range. Costs are higher than off-the-shelf equivalents — expect a premium of 40-80% depending on the specification — but this is almost always more cost-effective and safer than attempting to modify a standard door to fit a non-standard opening.

Avoiding Common Pitfalls

The most common mistake in ordering made-to-measure fire doors is inaccurate measurement. A door manufactured to incorrect dimensions cannot be trimmed down significantly without compromising its fire rating. Double-check every measurement, and if possible, have a second person verify them independently. Also ensure that the frame specification matches the door — a made-to-measure door still needs a compatible fire-rated frame, and this should ideally be ordered at the same time from the same manufacturer to guarantee the assembly has been tested together.