A major residential refurbishment project in Glasgow has highlighted Sto’s ability to provide a fully integrated insulation and render solution for major projects. The company’s high-quality StoTherm Mineral external wall insulation and StoLotusan render have been used on three large 1960s apartment blocks which are located on the Cedars development in the city’s north-west Woodside district.

“This was a very high-profile project which posed its own particular challenges from an insulation point of view,” says project architect Rupert Daly of Collective Architecture. “Our aim was to target the ultra-low energy Passivhaus EnerPHit standard for refurbished buildings, so we were keen to specify high-quality products for the insulation and system components. By seeking to improve the thermal performance of the buildings well beyond current UK building standards we aimed to reduce space heating demand by as much as 80%, significantly improve occupant comfort and mitigate fuel poverty.”

The StoTherm Mineral system features mineral fibre boards which provide highly durable external wall insulation and unrivalled fire protection. “These were important features as we wanted a high-quality system which would provide longevity, but which also delivered the appropriate fire protection performance for multi-storey buildings such as these,” adds Rupert. “The Sto system was able to deliver in every area.”

On refurbishment projects such as this, the efficient single-leaf construction of the StoTherm Mineral system allows a building’s thermal performance to be significantly improved without reducing the interior spaces, whilst minimising disruption to occupants.

“The StoTherm Mineral boards were mechanically and adhesively fixed to the substrate and feature specific Sto starter-track profile detailing to prevent cold-bridging – ideal for a project such as this where reliable insulation performance is a crucial requirement,” adds Daniel Mackie of insulation specialists Hamilton (BC) Ltd who installed the Sto system.

Given that the height of the buildings makes access for regular cleaning extremely difficult, the choice of the external render applied to the insulation was important. Once again, Sto provided a solution which met all the requirements in the form of its StoLotusan render, which is the only render with the patented super hydrophobic Lotus-Effect®. The surface of the StoLotusan features a unique microstructure similar to that of a lotus leaf. This prevents dirt particles from adhering to the render, and allows rainwater to simply remove the particles as it rolls off the façade. This provides excellent protection against the growth of algae and unsightly staining, and will allow the Cedars buildings to retain their attractive appearance well into the future.

“The new insulation was one of a long list of improvements made in order to create warm and comfortable homes for residents,” explains John Boyle, Head of Property Services, of Queens Cross Housing Association, which owns the properties. “This complex project’s aim was to transform outdated 60s properties into high quality city homes and improving the thermal performance was key to achieving that.”