Whole Window U Value Calculator
Calculator for Windows and Doors
Our U Value Calculator is designed to calculate the accurate u-value of bespoke design windows and doors. It can be a single paned window/door, or one with a number of panes of glass.
Whole Window U Values
This is a whole window calculator that works out the combined u value of the glazing, the frame and the spacer. We do not just supply a u-value taken from the centre point of the glass or the centre of a window panel.
Why you now require u-values
Building Regulations 2021 edition, Approved Document L has been updated to cover limiting heat gains and losses. The new rules related to the standards for fabric performance of building elements came into effect in June 2022 and cover minimum U-value requirements. Windows in new dwellings now have to have a u-value rating of 1.6W/m2K or less.
Our calculator is designed to easily calculate the u-value of windows and doors to see if they comply with these regulations. Our calculator does not restrict you to using products from any specific manufacturer. nor do you not need to be a member of our site or download any additional software.
We can calculate the u value of single, double or triple glazed windows built with softwood, hardwood or accoya frames. If you can provide the u-value for any upvc frame then we can work out a u-value for that too.
We can make adjustments for window and doors with or without spacers and any thermal bridges used in the installation.
No Membership Required
You do not need to be a member of our website to make use of our calculator. It is open to use by anyone. You can use it as often or as little as you want. From one window to a thousand. Contact us for discounted rates where several windows are involved.
Conforms to European Standard EN ISO 10077
Our U Value Calculator will provide you with a calculation that is performed in accordance with the U-Value equation provided in European Standard EN ISO 10077 part 1 Thermal performance of windows, doors and shutters. It will provide an accurate u-value that will satisfy your building control.
U Value Certificate
On submitting the required details to us and on receipt of the necessary payment, we will calculate your U-value and send you a certificate with a unique serial number for that window or door. You can then use that certificate to demonstrate compliance with Building Regulations (depending on the U-values that were obtained).