This case study explores how Leicester City Council were able to deliver an effective ‘de-build’ solution to Goscote House, a tower block that was constructed using a Large Panel Systems (LPS).
Summary
This case study explores how Leicester City Council were able to deliver an effective ‘de-build’ solution to Goscote House, a tower block that was constructed using Large Panel Systems (LPS). Goscote House faced unique site constraints that presented a high safety risk to traditional demolition, which required the council to consult industry specialists, Health and Safety Executive (HSE) and local fire and rescue services in order to pursue the demolition approach.
Introduction
Goscote House is one of five tower blocks on the St Peter’s Estate owned and operated by Leicester City Council. The other blocks on the estate have recently been refurbished as part of the council’s tower block refurbishment project. Another option had to be considered for Goscote House due to safety concerns around its construction.
The site was built in 1973, was 23 stories high and consisted of 134 one and two-bedroom housing units, with communal facilities on the ground floor. It was a challenging block with residents on the estate concerned about anti-social behaviour both inside and outside of the premises This made it a challenging block to let to potential tenants.
The tower was constructed by Taylor Woodrow using the large panel system (LPS) construction method. LPS was a popular construction method during the 1960s and 1970s involving the installation of prefabricated concrete panels, assembled on-site to form the structural walls and floors of multi-storey buildings. The LPS method promised to deliver cost-effective and speedy construction, but it was fraught with risks. One of the main risks associated with LPS construction was the potential for structural failure due to poor workmanship, lack of construction supervision, and inadequate structural testing. The Ronan Point disaster of 1968, in which a gas explosion caused the partial collapse of a 22-storey building, brought these risks to the forefront of public consciousness, and led to significant changes in building regulations.
The Ronan Point disaster was a turning point in the history of UK construction. It exposed the dangers of the LPS construction method and led to a complete overhaul of building regulations. The disaster highlighted the importance of ensuring that buildings were designed and constructed to be structurally sound and resistant to external forces. As a result, building regulations were tightened, and more stringent testing procedures were put in place to ensure that buildings constructed, using the LPS method, were structurally improved, however there have been multiple examples where the strengthening works were not completed adequately.
Leicester City Council commissioned a structural assessment report in 2017/18 on Goscote House. Alongside the known safety concerns with LPS construction, the report demonstrated that significant investment would be required if the building were to remain standing and so, a long-term future for the building could not be justified.
What triggered the project?
The risks associated with the LPS method were clear and posed serious safety and sustainability concerns for Goscote House.
After gathering information from multiple sources, including how other authorities were dealing with LPS safety issues nationwide, Leicester City Council determined that a comprehensive assessment of the future of the blocks was necessary.
Following the 2017 Grenfell tragedy, the fire brigade implemented several safety protocols that revealed the potential inadequacy of the building, emphasising the urgency for a new approach at Goscote House.
The risk that needed to be addressed
The specialist report highlighted a number of concerns that needed to be addressed to ensure the future safety of the block. The report was specifically designed to ensure that invasive testing was carried out. This important step ensured that several areas of the building were intrusively inspected to ensure that the condition of the wall and slab panels, the reinforcement, dry pack mortar and concrete quality were satisfactory. The report highlighted no initial concerns in the areas inspected. It was however noted that blocks constructed in the same way, in other areas of the county, are now starting to show signs of stress fractures, with landlords deciding to vacate the blocks as a precautionary safety measure.
In addition to the structural safety elements, the Leicestershire Fire and Rescue Service were particularly interested in the future of the block. Goscote House was subject to a recent prohibition notice requiring the council to carry out significant improvement works, including a wet riser on all floors, ensuring the fire and rescue service has access to water in the event of a fire. The cost for this work, alongside considerations for a sprinkler system, began to make any refurbishment plans financially difficult.
For the block to remain a viable, safe option for tenants, considerable reconfiguration work would be required to ensure the units are attractive to modern-day tenants. The structural safety report highlighted the need to restrict substantial reconfigurations including limitations to external cladding due to concerns of extra weight loading affecting the structural stability of Goscote House.
Highlighting the change
The cost of refurbishment was looking to exceed £20 million. With a refurbishment project not being able to provide guarantees on the lifespan and safety of the premises, a decision was made in 2018 to demolish the building with a view to redeveloping the site to provide a more attractive residential option in the future.
The demolition of Goscote House was particularly unique, the site constraints meant that a traditional demolition project was not safe, and the site was very closely located to a number of residents, businesses, and health and community centres which meant another option was required.
Due to the uniqueness of the site constraints, Leicester City Council engaged with industry specialists to ensure learning from national best practices was applied. This demolition specialists subsequently recommended a ‘de-build’ option; in which the building would be taken down, panel by panel, from the top using a tower crane. This option guaranteed the building was taken down safely, restricting the dust and debris and allowing for closer control of demolition stages. On this basis, the council chose to follow the specialists’ recommendation of a ‘de-build’
In addition to this, the Health and Safety Executive (HSE) was engaged at a very early stage and consulted on the demolition approach. Working with the HSE ensured safety, best practices were knitted into the demolition project from inception, creating a safe environment for local stakeholders and demolition contractors.
Goscote House was placed in the centre of the community making it necessary for the council to ensure local stakeholders were supported during its demolition. Leicester City Council adopted several principles that supported local residents and businesses to ensure their needs were met during the demolition process.
The council carried out an engagement process with local service providers, medical centres, community centres and housing associations that manage the residential properties in the vicinity of Goscote House. This process ensured the project plans were communicated to all stakeholders alleviating any concerns. The council put in place several planned activities and communication briefings, including a live webcam showing the progress of the demolition and a regular window cleaning service to ensure local premises did not suffer a build-up of dust from the demolition.
Further specialist collaboration was undertaken with Leicester Fire and Rescue Service such that once the block was empty, it could be used to train firefighters on how to deal with a fire in a high-rise block.
The de-build of Goscote House is approaching completion with two stories remaining as of March 2023. The demolition has been completed without incident, demonstrating the value of Leicester City Council’s planning and engagement with industry specialists.
Lessons learned
Early in the options appraisal process, the council recognised that the potential demolition of Goscote House was unique due to the site constraints presenting a high safety risk to the project.
The council engaged at a very early stage with industry specialists; including demolition specialists, the HSE and the local fire and rescue service to design a de-build option that would create a safe project for all stakeholders.
The decision on the future of the blocks was built using expert opinions to get a full view of the risks and opportunities of any potential scheme. The decision to undertake fully intrusive structural surveys provided enhanced assurance to visual inspections giving accurate information to make an informed decision.
The council communicated the issues with Goscote House to all stakeholders at an early stage of the project, ensuring that local businesses, residents and the wider community were aware of the future plans for Goscote House.