Replace Cladding

Definition and Scope of Cladding Replacement#

To replace cladding is the process of removing an existing external wall system and installing a new one. In the context of the UK built environment, this term typically refers to a comprehensive remedial strategy where the original rainscreen, insulation, and often the supporting subframe or fire cavity barriers are decommissioned and substituted with different components.

The scope of a replacement project is dictated by the specific deficiencies identified during a professional assessment. While the term is often used colloquially to refer only to the outermost decorative panels, a technical replacement usually encompasses the entire build-up from the structural substrate outward. This ensures that the new system functions as an integrated unit, meeting contemporary performance standards for moisture management, thermal efficiency, and fire performance.

The Role of Replacement in Building Remediation#

Replacement is generally considered when a building’s existing external wall system is found to be unsuitable for its intended purpose or fails to meet the standards set by current building regulations. In the UK, this often follows a detailed intrusive inspection, such as an EWS1 (External Wall System) assessment or a PAS 9980 appraisal.

Unlike localized repairs or minor maintenance, replacement is a wholesale capital work. It is typically recommended when the components of the existing wall system are deemed fundamentally incompatible with modern safety requirements or when the cost of piecemeal repair exceeds the value provided by a full system upgrade. The decision to replace is based on the professional judgment of fire engineers and building surveyors who evaluate the risk profile of the building’s specific configuration.

External Wall Systems and Building Fabric#

An external wall system is a complex assembly of multiple layers. When a replacement is undertaken, the relationship between these layers must be carefully managed to maintain the integrity of the building fabric. The replacement process usually involves:

• Rainscreen Panels: The visible outer layer, which may consist of aluminium composite material (ACM), high-pressure laminate (HPL), metal trays, or terracotta tiles.
• Insulation: The thermal layer, which must be assessed for its reaction to fire and its compatibility with the new rainscreen.
• Subframe and Fixings: The rails and brackets that secure the cladding to the building structure.
• Cavity Barriers and Fire Stops: Critical safety components designed to prevent the spread of fire and smoke within the cavity.

Replacing one element often necessitates the replacement of others to ensure the system’s tested performance remains valid. For instance, installing a heavier cladding material may require a more robust subframe, while changing the insulation thickness may necessitate a redesign of the cavity barrier layout.

Regulatory Context in England and Wales#

The regulatory framework for cladding replacement in England and Wales has undergone significant transformation, primarily through the Building Safety Act 2022 and updates to the Building Regulations (specifically Approved Document B). For buildings over 18 metres (or seven storeys), there are stringent requirements regarding the combustibility of materials used in the external wall.

Any cladding replacement must be submitted for Building Control approval. For high-rise residential buildings, the Building Safety Regulator (BSR) acts as the building control authority. The process requires a thorough demonstration that the proposed new system complies with all relevant functional requirements of the Building Regulations.

Considerations for Building Owners and Managers#

Building owners, managing agents, and directors of Residents' Management Companies (RMC) or Right to Manage (RTM) companies must navigate the legal, financial, and logistical complexities of cladding replacement. A primary concern is the identification of the 'Accountable Person' or 'Principal Accountable Person' under the Building Safety Act, who holds the legal responsibility for ensuring the building’s safety risks are managed.

The replacement process begins with the procurement of a competent professional team, including a lead consultant, a fire engineer, and a facade specialist. This team develops a specification for the new system, manages the tender process, and oversees the construction phase. It is essential for stakeholders to understand that replacement is not merely an aesthetic choice but a technical necessity driven by safety and compliance. Financial considerations, including the potential for government funding through schemes like the Building Safety Fund, also play a significant role in the planning stages.

Common Misunderstandings#

A frequent misunderstanding is the belief that replacing cladding only involves swapping the outer panels. As noted, a compliant replacement often requires a full redesign of the internal cavity and insulation layers. Another misconception is that all cladding systems on buildings of a certain age or height must be replaced by default. In reality, the requirement for replacement is determined by a risk-based assessment (such as PAS 9980) which considers the building’s unique context, including its occupancy, height, and existing fire safety measures.

There is also confusion regarding the term "like-for-like" replacement. In the current regulatory environment, replacing a system with an identical but non-compliant system is not permitted. The new system must meet the standards in force at the time the replacement work is carried out, which often means moving from a combustible or limited-combustibility system to one that is strictly non-combustible.

Related Terminology#

Understanding the term "replace cladding" requires familiarity with several related technical concepts:

• Remediation: The overarching process of correcting defects in a building's construction or fire safety systems.
• Re-cladding: A term often used interchangeably with replacement, though sometimes used to describe the addition of a new layer over an existing one (over-cladding).
• Mitigation: Temporary or permanent measures taken to reduce the risk posed by a building’s external wall system while awaiting full replacement.
• Combustibility: The measure of how easily a material or system will burn, often categorized by Euroclass ratings (e.g., A1, A2-s1, d0).
• Intrusive Survey: A physical inspection where sections of the cladding are removed to examine the internal components and construction quality.

The distinction between these terms is vital for clear communication between building owners, regulators, and contractors during the lifecycle of a remediation project.