Cladding Safety

Definition and Scope of Cladding Safety#

In the technical context of the UK built environment, cladding safety refers to the systematic assessment and management of risks associated with external wall systems. While the term is often used colloquially to denote the absence of immediate hazard, in a professional and regulatory sense, it describes a framework of engineering, surveying, and administrative processes designed to ensure that the building envelope performs in accordance with applicable functional requirements.

The scope of cladding safety encompasses the entire external wall assembly. This includes not only the outer rainscreen panels but also the insulation, cavity barriers, fire stops, sub-frame systems, and the method of attachment to the building’s primary structure. The objective is to evaluate how these components interact under various conditions—principally in relation to the spread of fire and structural integrity—to determine whether the assembly meets the standards set out in national building regulations.

Role in Testing and Remediation#

Cladding safety is the central objective of professional site investigations, such as those conducted under the PAS 9980:2022 code of practice. During the testing phase, surveyors and engineers collect data on the materials present within the wall system. This often involves intrusive inspections, where small sections of the cladding are removed to reveal the internal composition and the presence (or absence) of fire-stopping measures.

Where a building’s external wall system is identified as not meeting current standards, the term frames the subsequent repair or replacement work. In the UK, this process typically follows a specific sequence:

• Initial Assessment: Qualitative and quantitative data collection regarding the building’s construction.
• Risk Appraisal: Determining the proportionality of the risk posed by the existing system.
• Design and Specification: Identifying suitable replacement materials or remedial actions.
• Execution: The physical removal of non-compliant materials and the installation of tested, appraised systems.

Building Fabric and External Wall Systems#

The term is inextricably linked to the 'building fabric'—the physical components of a building that separate the internal environment from the external. The external wall system is a complex, multi-layered assembly where the performance of one component is dependent on the installation of another. For instance, even if the outer cladding panels are of limited combustibility, the overall safety of the system may be compromised if cavity barriers are missing or incorrectly positioned, as this could allow fire to bypass the protective layers.

In the UK, the technical understanding of cladding safety has shifted from a component-based view to a holistic system-based view. Professionals now evaluate the 'as-built' condition rather than relying solely on the theoretical performance of individual products. This takes into account factors such as the height of the building, the proximity of other structures, and the presence of specific features like balconies or recessed windows, all of which influence the technical assessment of the wall system.

Regulatory Context in England and Wales#

The regulatory landscape governing cladding safety has undergone significant transition, primarily through the Building Safety Act 2022 and the Fire Safety Act 2021. These pieces of legislation provide the legal basis for how external walls are managed throughout the lifecycle of a building. In England and Wales, the Building Safety Regulator (BSR) now oversees the safety and performance of high-rise residential buildings (HRBs), typically defined as those at least 18 metres tall or with at least seven storeys.

Central to this context is the concept of 'functional requirements.' Building regulations do not always mandate specific materials but instead require that the external walls adequately resist the spread of fire over the façades and from one building to another. For buildings over 18 metres, current regulations in England have introduced stricter limitations on the use of combustible materials, effectively requiring most components of the external wall to achieve a European Class A2-s1, d0 or A1 rating, subject to specific exemptions.

Responsibilities for Building Owners and Managers#

Building owners, managing agents, and directors of Resident Management Companies (RMC) or Right to Manage (RTM) companies hold significant responsibilities regarding cladding safety. Under the current regime, these parties are often designated as 'Accountable Persons' or 'Principal Accountable Persons' for high-rise buildings. Their primary duty is to assess and manage 'building safety risks,' which specifically include the spread of fire and structural failure.

Understanding cladding safety at a board or management level involves navigating the following technical requirements:

It is essential for these stakeholders to recognise that cladding safety is not a one-time certification but an ongoing management requirement. Maintenance of the external wall, including ensuring that no unauthorised alterations are made by residents (such as the installation of satellite dishes or vents), is a critical component of long-term risk management.

Common Misunderstandings#

A frequent misunderstanding is that cladding safety relates solely to the presence of Aluminium Composite Material (ACM). While ACM was a primary focus of initial remedial efforts, the technical definition covers all types of rainscreen, rendered systems, High-Pressure Laminate (HPL) panels, and timber cladding. Any material that contributes to the external wall assembly falls under the remit of safety assessments.

Another misconception is that an EWS1 (External Wall System) form is a statutory safety certificate. In reality, the EWS1 is a valuation tool created to assist the mortgage market; it does not replace the legal requirement for a Fire Risk Assessment of the external walls under the Fire Safety Order. Furthermore, a 'passed' assessment does not imply the building is fireproof; rather, it indicates that the risk posed by the external wall system has been appraised as being at an acceptable level according to current professional standards and guidance.

Related Terminology#

The vocabulary of cladding safety is dense and technical. Closely related terms include:

• Combustibility: The measure of how easily a material will burn or contribute to a fire.
• Cavity Barrier: A piece of fire-stopping material placed within a wall cavity to prevent the passage of flame and smoke.
• Limited Combustibility: Materials that provide a low contribution to fire, typically classified as A2 under BS EN 13501-1.
• Mitigation: Actions taken to reduce the severity of a risk when total removal of a material is not immediately possible or required.
• Competent Person: An individual with the necessary skills, knowledge, and experience to carry out a specific technical task or assessment.

Professional assessment of these factors is mandatory to determine the specific requirements of any individual building.