This case study explores how Sandwell Metropolitan Borough Council were able retain their two remaining tower blocks that were constructed using Large Panel Systems (LPS). The council’s strong internal high-rise building safety team and engagement with external industry experts have led to the council managing and retaining the two remaining LPS tower blocks rather than pursuing demolition.
Introduction
The tragic collapse of the Ronan Point 22-storey tower block in East London in 1968 encouraged councils and landlords to review their stock of high-rise buildings that were built using similar construction methods. The construction method saw concrete panels bolted together on-site to form the structure of the building. The collapse at Ronan Point occurred on the eighteenth floor, where a gas explosion caused the failure of one of the precast concrete panels that formed the load-bearing walls. The explosion occurred when a tenant was using a gas stove, and the gas ignited, causing the panel to fail. The failure caused a progressive collapse of the floors above, leading to the partial collapse of the building.
The investigation into the collapse revealed that the design of the building did not account for the structural weaknesses of the prefabricated concrete panels. The panels were not strong enough to resist lateral loads, such as wind or an explosion, and there were no structural connections between the panels and the floors or the walls. As a result, the failure of one panel caused a chain reaction that led to the collapse of the building.
The results of the investigation asked large panel system (LPS) building owners, including local authorities, to carry out routine inspections of the buildings and to complete structural improvements to mitigate the concerns raised by the Ronan Point collapse.
Sandwell Metropolitan Borough Council were a large stakeholder in the review and actions required from LPS buildings, as they had 16 LPS premises within their housing stock. Over the years, 14 of the LPS tower blocks were decommissioned and demolished, not due to issues with the LPS construction, but to adapt to a more modern residential planning approach.
Sandwell Metropolitan Borough Council now have two LPS blocks remaining, Kynaston House and Russell House. The two remaining buildings are both 11 stories tall, are very similar in design and layout, and were built in the mid-1960s.
The council have completed extensive refurbishment and structural assurance works over the years on the two blocks to ensure tenants’ safety. This included structural safety works to address the concerns raised during the Ronan Point investigation. Regular visual inspection works are completed by a specialist building surveying organisation that reports any degradation of quality to the council. Any identifiable issues can then be rectified. This regular information gathering has enabled the council to act early on signs of deteriorating standards which have led to several structural improvements, including the replacement of external building ties which were demonstrating signs of rust.
The council have a strong and established internal high-rise building safety team, which includes a number of subject matter experts. This in-house team has established a robust set of policies and procedures that have enabled the council to have full assurance of the building’s safety.
The depth of internal knowledge has led the council to manage and retain the two remaining LPS tower blocks rather than pursuing demolition. This decision is supported by a range of safety measures that allow the blocks to continue to provide safe accommodation to the tenants.
The risk that needed to be addressed
The risks associated with LPS buildings are well known nationally with excellent information on construction safety provided by the Building Research Establishment (BRE). The BRE is a UK centre of building science that focuses on improving safety and raising the standards of the built environment. Sandwell Metropolitan Borough Council have regularly engaged with the BRE around their LPS premises providing external assurance to their improvement schemes. This collaboration saw the Sandwell LPS blocks being used as a pilot scheme by the BRE in the 1990s to assess and recommend safety measures in a national report provided to support building owners.
Operating a high-rise LPS building is not without its risks and Sandwell Metropolitan Borough Council have put in place a vast suite of risk mitigation measures to ensure the safety of the buildings.
Measures to ensure safety
Sandwell Metropolitan Borough Council have a range of specialist in-house resources but continues to engage with external experts to provide assurance on their risk mitigation measures. The collaborative relationship continues with the BRE, which supported the decision to install external cladding to the buildings in 2010, to improve both the aesthetics and the thermal efficiency of the premises, making the housing units easier to heat for tenants.
The 2017 Grenfell tragedy put a national focus on external cladding with several authorities and landlords being forced to remove cladding in response to new guidance and regulations. Sandwell Metropolitan Borough Council were able to retain the cladding on the LPS buildings as the purchasing decision was rooted in fire safety, with the support of the BRE the council selected cladding with enhanced fire safety rating in 2010.
The focus on fire safety within the LPS buildings is extended to the operational management and policy within the blocks, with a number of local fire safety measures helping to ensure tenants’ safety. Examples of these elevated fire safety measures are as follows:
- Regular fire risk assessment processes for the blocks, ensuring the existing measures are in place and operational and assessing the fire risk profile of the premises
- the removal of gas to the blocks; which includes a ban on the use of paraffin oil, petrol, bottled gas appliances or any other explosive, flammable or dangerous material in the property
- regular checking of fire safety measures by the council housekeeping team who check the operation of fire doors and their closures, the security of vulnerable areas and the condition and cleanliness of communal areas 365 days a year
- the installation of automatic smoke ventilation which is tested, inspected and maintained by a competent external contractor
- the premise has sufficient compartmentation to limit the travel and effect of smoke and flames in the event of a fire, to support a stay-safe policy. Therefore, residents are advised to remain in their flats unless the fire directly affects them
- FD30 fire doors throughout the blocks that are regularly assessed for damage or degradation
- a water drenching system is provided to the refuse chute bin store which is inspected and maintained by an approved contractor.
Due to the focus on fire safety the local fire and rescue service regularly engage with the council to discuss fire safety measures and gain assurance of residents’ safety. This collaborative relationship ensures the fire service is familiar with the premises, which supports the response to any emergency and helps to provide external assurance that the fire safety measures are appropriate.
Learning points
Owning and operating LPS premises is not without risk, but Sandwell Metropolitan Borough Council have assured themselves of the safety of the building through the strength of internal knowledge and collaboration with external subject matter experts.
Decisions have been made throughout the lifespan of the two buildings that had fire safety at its core. This helped to ensure the premises remained safe, and compliant with emerging fire safety changes.
Having an open and transparent relationship with external specialists has improved the national knowledge of LPS safety.
Engagement with the local fire and rescue service has improved their local knowledge of the blocks, improving any response to an emergency situation.