Corbett House Retrofit

Project Overview 

Bristol City Council identified Corbett House, a 14-storey residential tower, as needing urgent refurbishment due to ageing and less effective external wall insulation (EWI). The previous insulation system was unreliable and provided poor thermal performance. This resulted in high energy bills for residents and uncomfortable living conditions.

To resolve these issues, K Systems, in partnership with Synergize Ltd, led the transformation of Corbett House. They ensured compliance with the latest fire safety regulations while dramatically improving the building’s energy efficiency and aesthetics.

Key Solutions

The project involved a full upgrade to the EWI system. The top priority was to improve the safety and energy efficiency for the residents. The transformation was achieved by: 

• Non-combustible 140mm Rock Mineral Wool Insulation: The outdated EPS insulation was replaced with rock mineral wool. This is a non-combustible material which improves fire safety and thermal performance.
• K Systems M VBriQ+ and K Systems M Silicone TC15: For the ground floor of the building, M VBriQ+ provided a real brick-slip finish. This combines the highest level of impact resistance with an A1 fire safety classification. 

From the first floor up, M TC15 was used. TC15 is a breathable and hydrophobic silicone render. M TC15 achieves an A2-s1,d0 fire test rating and protects the building from the elements.

• Direct Fix EWI System: Applied in specific areas where balconies had been removed prior to the works. The system was integrated with a Metsec design to increase the height of the windows for alignment. This ensured a seamless installation while maintaining high standards of safety and performance.

By the end of the project, the building's U-value improved to 0.24 W/m²K. This significantly increased energy efficiency and lowered the heating costs for residents.

Challenges and Tailored Solutions

The project presented a variety of challenges, all of which were handled with strategic planning and innovative solutions:

• Limited On-Site Storage: Given the tight urban conditions surrounding Corbett House, on-site storage for materials was minimal. K Systems managed this by implementing a just-in-time delivery schedule. This ensured materials arrive as needed without overwhelming the site. 
• Construction Consistency: The mix of steel frame and masonry construction required detailed technical designs. This ensured a consistent finish across different sections of the building.
• Material Supply Management: With long lead times for mineral wool insulation posing a potential delay. Weekly planning meetings ensured continuous material availability, preventing any project delays. 

These tailored solutions ensured the project stayed on track, meeting both safety standards and the client’s timeline. 

Results and Project Impact

By March 2024, the Corbett House refurbishment was completed successfully. The building now meets the highest standards of fire safety and energy efficiency. 

The project also contributed to Bristol City Council’s decarbonisation strategy. This helps the city move closer to its sustainability targets. Additionally, the building's new exterior provides a modern, refreshed look. 

The collaboration between K Systems and Synergize Ltd shows how expertise can overcome challenges in complex and high-rise projects. Corbett House now serves as a model for safe and efficient residential refurbishments.