Mostly constructed between 1947 and 1948, BISF houses were designed and produced by the British Iron and Steel Federation, BISF houses are metal frame clad dwellings with a profiled steel sheet on the first floor, with render supported on expanded metal mesh on the ground floor. Built cheaply and quickly after the war to deal with the massive housing shortage. BISF houses had a life expectancy of less than 50 years.
Corrosion can be a problem with the metal cladding on the first floor, and also the feet of the steel legs. But these faults can be easily corrected. The metal cladding can be removed if is suffering from excessive corrosion but if not can be retained as the sheathing on which to apply the external wall insulation. Once any corrosion has been dealt with the BISF house is simple to over clad with external wall insulation.
External wall insulation in the UK started with the insulation of system built properties over 30 years ago. Virtually all of these properties remain standing with very little or no further maintenance required to their external fabric, essentially doubling their life expectancy. It is only right that the industry should be proud of such an achievement and consider such a project for its heritage award
Fourteen years ago, SPSenvirowall supplied its EWI systems for a refurbishment scheme implemented by Dartford Borough Council. INCA members and installers, Retrofit, carried out the work to 20 BISF houses which extended their life for at least a further 25 years, allowing the tenants to remain in their homes. These are large 3 bedroom properties with nice sizeable gardens, in this part of the world, new houses have not anywhere near the space internally or externally. Probably a small patch of paving slabs or AstroTurf as a garden. Many of these houses have a large patio, sizeable lawn area and vegetable patch with a big shed and garage. The use of external wall insulation has created warm, attractive homes the like of which would be otherwise unattainable for most of the residents living in these properties.
SPSenvirowall’s Wall System 2 was utilised in this project, incorporating phenolic insulation with brick render to the ground floor and dash to the first floor, designed to provide a cost effective, attractive and robust system, ideally suited for this type of refurbishment. The alternative to insulating would have been demolition and rebuild. These houses are now warm, cheap to run, are attractive places to live and have aged very little since the installation 14 years ago. A perfect showcase for capabilities of external wall insulation.