External Wall Insulation Alumasc’s BBA approved, fully warranted external wall insulation systems are available with a choice of insulating material and render facings, providing design and specification options across many building types including commercial, retail, education, leisure and residential markets. New Build - External Wall Insulation Alumasc’s Swistherm and Swisrail External Wall Insulation systems are primarily suited to new build applications. Swisrail is NHBC compliant and features a drainage cavity between the insulation and the structural frame. Select System: Swistherm Swistherm with Cork Swisrail Refurbishment - External Wall Insulation Alumasc Swisslab and Swisspan External Wall Insulation systems are primarily suited to refurbishment applications, with an impressive track record in transforming poor quality housing conditions into warm, dry, energy efficient homes. Select System: Swisslab Swisspan