windows and doors

How to Measure for New Windows

If you want to put up some new timber-framed windows in your home, the first thing you’ll have to do is measure the area. This involves more than simply getting out the tape measure and a pencil and pad.

You need to make sure you measure the space accurately because otherwise you’ll end up with windows that don’t fit. And if this happens, the only solution is to order new windows at additional expense.

Here is a guide to how to measure for new windows and ensure they are the correct size.

Always Measure in Millimetres

First of all, make sure you’re measuring in metric. Forget about inches – for windows, you need to keep the measurements in millimetres. This will provide you with more accurate measurements, and there is also no need to convert inches to millimetres later on, which could lead to mistakes.

Ignore Your Frame

When you have your measuring tape ready, know which part of the window to measure. You will want to ignore the old frame because this is irrelevant for the measuring process. It’s an easy mistake to make, but the fact is the frame might have warped, and if so it will not give you an accurate measurement.

Head Outside

To take the measurement accurately, go outside. The area you want to measure for your new window is the outside opening, or the masonry opening as it’s referred to. You might have to go up a ladder, so be careful if so and get someone to foot the bottom.

Take a Number of Measurements

Next, you’ll want to start measuring. The area you want to measure is from brick to brick, top to bottom and side to side. This will provide you with accurate measurements for the height and width of the windows.

Aim to take three or more measurements of the height and width in case the opening is not exactly square or rectangular. Write down all the measurements as you go. Even better, draw a picture of the window and write down where you are measuring.

You want to measure the opening at the bricks. If you have a windowsill that will be removed, you must measure from underneath this. If your window has a lining, measure its width. This will be removed, so you will want to add it to the measurement you took for the opening.

Are the Sides the Same Length?

Measure from one corner to the opposite corner, and then again on the other side. Are they the same length? This will tell you whether it is square, rectangular or neither. If these measurements are different, let your manufacturer know.

Take Off Space for Fitting

While you should provide the exact measurements to the manufacturer, make sure you also account for fitting. You will need to take off 10mm from each measurement from the height and width to account for the fitting. This is used to make sure the window can be levelled and square. If any gaps are left, these can be filled later.

Measure the Depth of the Window

You should also measure the depth of the window, otherwise your new window might be too deep to fit the space. Simply measure from the outside to the inside of the frame, and again do this in a few different places.

Do It All Again

Always make sure you have accurate measurements. You can do this by measuring them a second time to double check. If you have got them wrong, you will have to buy another window, so it’s worth getting the measurements right the first time round.

Pass on Your Measurements to the Manufacturer

Once you are sure of your measurements, pass them to the manufacturer. Again, a drawing showing the measurements can help so there is no misunderstanding. Always make sure that your drawings are as viewed from outside, and that arrows point towards the hinges. If everything is in order, your manufacturer will use your measurements to provide you with your new windows, and you can then enjoy getting them fitted.

Another option, of course, is to contact the window manufacturer and ask them to take the measurements on your behalf. Here at Timber Windows, we are highly experienced at taking window measurements that are accurate and correct.

Sometimes it really is best to leave things to the professionals.