INCA Case Study: Millbank And Ergon House, London​

This large and prestigious high-rise project entailed the refurbishment of a historic building in the centre of London – Millbank House and also the construction of a new building to replace the existing – Ergon House.

The Sika Parextherm EWI system was comprised of non-combustible Stone Wool, and the high-performance Sika Parex Siloxane render finish. The system was installed to the entirety of the huge, central courtyard.

The project was complicated, and a number of challenges had to be overcome to ensure the successful completion of the scheme. There were six different specifications written for the project and all of these six variants were used within the finished project.

There were three differing thicknesses of Stone Wool insulation used within the EWI system and a number of differing substrates that these were installed to.

• 150mm Stonewool system with Siloxane Render finish onto SFS and incorporating a 25mm drained cavity, some of which was also required to be installed onto masonry.
• 30mm Stonewool system with Siloxane Render finish onto sheathing and also, directly fixed to masonry.
• 90mm Stonewool system with Siloxane Render finish onto SFS and incorporating a drained cavity and also fixed to masonry.

The complexity of the project meant a heavy involvement at the design stage with the client (St Edward – Berkeley Group) and their architect, this ensured that the detailing and interfacing was robustly designed and the thermal performance requirements were achieved. Furthermore, this also ensured that potential detailing issues were addressed at the earliest stages.

The site itself posed several challenges as the access to the building was extremely limited, due to the site being within the heart of Westminster. This meant that the delivery of the Sika Parextherm materials had to be meticulously managed, in collaboration with the registered Sika installer.

Due to the technical complexities of the project there was heavy involvement with Sika’s technical team, who also carried out numerous site visits to support the registered installer and to ensure that the complex requirements of the project were being met through the correct application of the Sika Parextherm system in accordance with the relevant specifications.

The finished project looks incredible, the varying EWI specification requirements have been met and the end result belies the complexity of the project – as it looks seamless, clean and entirely in accordance with the architects’ vision.