U-value Calculations for Your Extension

Your assessment, explained

A U-value tells you how much heat passes through a wall, roof or floor. We calculate it from the materials and thicknesses in your proposed construction, giving you the figures and supporting calculations for building control.

This package covers three individual calculations: one wall, one roof and one floor construction. These describe the performance of each construction. If you need to balance extra glazing against improved insulation across an extension, that's an Area Weighted U-value check instead.