WARMERWALL by PolySteel is probably the most energy efficient building block you can use to build the walls of homes, apartments, hotels, commercial units, property extensions, basements, pools and also ideal for retaining walls including basements and strip foundations.I supply our insulated building block WARMERWALL to self builders, builders and property developers throughout the UK. WARMERWALL is manufactured in the UK and is ideal for self builders and property developers to build homes quickly and efficiently. Our homes are stronger than a standard traditional build and more importantly have a lower energy requirement to keep warm in the winter.