Changes

Definition and Scope of Changes#

In the context of the UK cladding industry, the term "changes" refers to alterations or modifications made to a building’s design, materials, or components. This encompasses both intended modifications during the initial construction phase—often recorded as "as-built" variations—and retrospective interventions during the lifecycle of a building, such as repair, remediation, or wholesale replacement of the external wall system.

A change is rarely an isolated event. Because the external building fabric is an integrated assembly of diverse components, a modification to one element—such as the specification of a rainscreen panel—frequently necessitates changes to secondary components, including insulation, cavity barriers, sub-frames, and fixings. In technical terms, a change represents a departure from the original design intent or the previously documented state of the building, requiring rigorous assessment to ensure the system continues to perform as intended.

Changes in the Context of External Wall Systems#

The external wall system (EWS) is a complex multi-layered assembly where thermal performance, moisture management, and fire safety are interdependent. When a change is introduced, it must be evaluated not just as an individual product substitution, but as a systemic alteration. For example, replacing a high-pressure laminate (HPL) or aluminium composite material (ACM) panel with a non-combustible alternative constitutes a significant change that may affect the wind-loading requirements or the hydrothermal performance of the wall.

In many high-rise residential buildings, changes are identified during the intrusive survey process. Professionals often discover that the materials installed during original construction differ from those specified in the original planning or building control applications. These "hidden" changes—substitutions made on-site without adequate documentation—form a primary focus of modern cladding remediation, as they may alter the presumed risk profile of the building fabric.

Regulatory Framework in England and Wales#

The regulatory environment regarding changes to building systems has undergone substantial refinement, particularly following the introduction of the Building Safety Act 2022. For buildings defined as "higher-risk" (typically those over 18 metres or seven storeys), the process of managing changes is governed by a stringent "Gateways" regime.

Any significant change proposed during the design or construction phase of a remediation project must be managed through a formal change control process. Under current regulations, changes are often categorised as either "major" or "notifiable." A major change requires approval from the Building Safety Regulator (BSR) before it can be implemented, whereas a notifiable change must be recorded and communicated to the BSR but may not require prior consent. This ensures that a digital thread of information is maintained, documenting exactly what was installed and why deviations from the original plans occurred.

Role in Testing and Remediation#

When cladding is tested—whether through small-scale material testing or large-scale system testing—the results are specific to the exact configuration of the test rig. Any subsequent change to that configuration in a real-world application, such as changing the width of the cavity or the type of mechanical fixing, can render the original test data inapplicable.

In the UK, the "Assessment in Lieu of Test" (often referred to as a desktop study) was historically used to evaluate these changes. However, current industry guidance emphasizes the necessity of robust evidence. If a change is proposed for a cladding system, a qualified fire engineer or building professional must determine if existing test data (such as BS 8414 results) supports the modification or if further physical testing or a new design approach is required.

Implications for Building Owners and Managers#

For Responsible Persons, such as Residents' Management Company (RMC) directors or managing agents, understanding "changes" is critical for long-term liability and insurance purposes. When a building undergoes remediation, the management of changes ensures that the final "as-built" information is accurate. This documentation is essential for the completion of EWS1 forms and for demonstrating compliance to insurers and mortgage lenders.

Failure to document changes can lead to significant difficulties during the "Golden Thread" handover. If the materials found on a building do not match the O&M (Operation and Maintenance) manuals, it suggests a lack of oversight during the construction or repair phase. Consequently, building owners must ensure that their professional team—including architects, surveyors, and contractors—operates a transparent change management system that captures every modification to the external wall.

Common Misunderstandings#

A frequent misunderstanding is that a "like-for-like" replacement does not constitute a change. In technical terms, even if a product is replaced with a similar item, differences in manufacturer specifications, batch variations, or updated fire classifications mean the replacement must be recorded as a change to the building's state.

Another misconception is that changes only refer to the visible outer cladding. In practice, some of the most critical changes occur within the cavity, such as the repositioning of cavity barriers or the introduction of new types of insulation. Because these elements are not visible after installation, they are often overlooked in informal change logs, despite having a fundamental impact on the system's performance.

Related Terminology#

The management of changes is supported by several related technical terms:

• As-Built Drawings: Documents that reflect the building exactly as it was constructed, incorporating all changes made during the build process.
• Material Substitution: The act of replacing a specified product with an alternative, which must be managed through change control.
• Golden Thread: The digital record of building information, intended to track all significant changes throughout a building's lifecycle.
• Design Variance: A formal departure from the original architectural or engineering plans.
• Remediation: The process of correcting defects, which inherently involves making changes to the existing building fabric.

Ultimately, the term "changes" signifies the evolution of a building's physical makeup. In the modern UK regulatory context, the emphasis is not merely on the change itself, but on the rigorous documentation and professional oversight required to ensure that every modification is accounted for and technically justified.