Insulation

Meeting Part L is rarely about chasing the thickest insulation you can fit. It is about hitting the right thermal performance, keeping moisture risks under control, and spending money where it actually reduces heat loss.

If you are working on a new build, extension, conversion, or a refurbishment that triggers Building Control, the practical question tends to be the same: what thickness do I need for the roof, walls, and floors in the UK, and how do I avoid paying for insulation I do not need? This guide puts typical thicknesses into context and explains where the costs creep in.