How to Read Uprichard Door Sizing Without Losing Your Mind
The Uprichard Size Guide is one of those documents that looks comprehensive until you're standing in a doorway with a tape measure and realizing the numbers don't match what's actually on your wall. I've gone through this process maybe a dozen times across different projects, and it still catches me out occasionally. Here's how to make it work. Start by understanding that Uprichard, like most UK door manufacturers, lists doors in two ways: the nominal size and the actual cut size. The nominal size is what you see on the spec sheet — 1981mm by 762mm for a standard internal door, for example. The actual cut size is usually 2mm to 3mm smaller on each dimension to allow for fitting. If you order based purely on the nominal size and your rough opening matches that exactly, you will not be able to get the door into the frame. Always subtract roughly 25mm from your rough opening width and 20mm from the height when working backward from an existing opening.
Uprichard Size Guide: What the Numbers Actually Mean
The guide breaks their ranges into a few main categories — internal doors, external doors, French doors, and patio doors. Each has its own sizing logic. Internal doors are the most straightforward, typically ranging from 686mm to 914mm in width and 1829mm to 2193mm in height. External doors follow a similar pattern but account for thicker profiles and different framing requirements. The trick with external doors is that the size guide assumes a certain wall thickness, and if your walls fall outside that range, you're dealing with special orders or additional trimming. For French and patio doors, the sizing gets more complicated because Uprichard uses paired configurations. A 1524mm French door isn't just two 762mm doors side by side — there's a central meeting rail and weather-seating consideration that affects the actual cut. The size guide will give you the overall aperture size, not the individual leaf dimensions. I once ordered what I thought was a standard 1524mm French door replacement and arrived at the site to find the new unit was 12mm narrower than the existing one because the guide calculates the overall rough opening, not the individual leaf width. I had to trim the reveal slightly on both sides to make it fit, which cost me about forty minutes and a trip back to the DIY store for filler. Thickness is another area people get wrong. Most Uprichard internal doors come in 35mm or 40mm thickness. External doors are typically 44mm. If you're replacing an existing door and the new one is the wrong thickness, you'll need to adjust the rebates in the frame or deal with gap issues around the edges. The size guide doesn't always make the thickness options crystal clear for each product line, so check the detailed spec sheet rather than assuming.
One thing the guide doesn't emphasize enough is the difference between hole size and door size when you're working with prehung units. A prehung door comes fitted in its frame, and the overall package size is what matters for the rough opening. If your existing opening is 2032mm high, a prehung door with an overall height of 2060mm simply won't go in, even though the door slab itself might be listed as 2048mm. Always check the prehung package dimensions, not just the slab size. The material also affects things. uPVC doors expand and contract with temperature. I've seen installations where a door that fitted perfectly in a cool warehouse sat flush at 18 degrees Celsius and then started binding against the frame at 28 degrees because the uPVC had expanded enough to eliminate the weep space. It wasn't a sizing error — it was a thermal movement issue that the guide doesn't really address. The workaround is leaving a slightly larger tolerance at the top and bottom when fitting in environments that see significant temperature swings, or specifying a door with an adjustable frame system if available. For measure-yourself accuracy, here's the process I use now instead of relying on the guide alone: measure the width at the top, middle, and bottom of the existing opening. Measure the height on both sides and diagonally. Take the smallest measurement from each set and work from there. This catches out-of-square openings that the size guide can't account for. If your measurements vary by more than 5mm across the opening, you're dealing with a non-standard situation and should probably contact Uprichard's technical support before ordering rather than guessing.
Get the Full Details
The size guide is a starting point, not a guarantee. It assumes your opening is square, plumb, and within standard tolerances. Real buildings aren't like that. Use it to narrow down your choices, verify with actual measurements, and build in a small adjustment margin. That's how I avoid the returns and the extra trips to the builders' merchants.
