Members’ Area Hints and Tips: The U-value Calculator

The Celotex U-value Calculator is one of the most comprehensive online calculators in the industry and is used by thousands of small to large architects and specifiers all over the country. So for this reason we have we have just made this bigger and better for our users to improve your experience.

You can create detailed U-value calculations in pdf format, instantly with the click of a few buttons at

New Celotex U-value Calculator

Firstly, log in to your Members Area, click on the U-value calculator icon.

Step 1

If you have an existing incomplete calculation, you can choose to carry on by locating this in the list at the bottom, or…. if you are starting a new calculation, choose your construction type and press continue.

Step 2

Choose your construction details and press continue.

Step 3

At this point you can see pre-defined build up values at the top and bottom, and some customisable variables in the centre.

Start defining these details by either selecting the insulation you require, or by entering a target u-value to adhere to.

Define the other required variable values, and then specify an appropriate filename to make it easier to locate at a later date.

At this stage you also have the choice of changing the address that appears on the specification. So if you are doing this on behalf of a client or specific project, you can adjust it accordingly.

Step 4

You will be presented with a set of calculations on screen and your specification will have been physically created in pdf format, which you can find in the “My U value calculations” section.

At this stage, you can add the u- value calculation PDF, as well as other related documents to a new or existing project. Simply tick any additional files you need and add press “add to a project”.

Select your project or enter a new project.

Step 5

All your files are added to your project folder and you can choose to download the pdf spec, or email it to yourself or a colleague.

So in 5 simple steps, there you have it- you U-value calculation for your application and if you have more calculations to perform for your project, you can also start your next specification using the build-up icons at the bottom.

Check out this quick video for a visual introduction of the Celotex U-value Calculator:

At Celotex, we always like to make things easily accessible on your mobile, so the full calculator is responsive to mobile devices too.

But we haven’t stopped there – you can also perform on screen calculations whilst out and about, using the new mobile app which is coming soon! You can simply continue with the detail and access the pdf once you get back into the office.

Our app is exclusively available to members only and can be downloaded through Google Play and Apple Stores, for Android and Ios devices.

Sign up the members’ area today at or if you are already a member try the new look calculator today at

Thanks to all our members that have provided feedback for these new improvements, we hope you like them!