From Risk to Resolution: Taking a Holistic Approach to External-Wall Performance

Understanding external-wall risk is only the beginning.

Once the construction has been established, the available evidence considered and the significance of the identified risks understood, building owners face a different question: What is the right response?

For external-wall issues, the answer is not always straightforward. An identified fire risk does not automatically prescribe a single solution, and an intervention developed to address one performance requirement can have implications for other aspects of the façade.

This is why resolution needs to consider the external wall as a whole.

From Risk to the Right Response

The purpose of Resolution is to turn an understanding of risk into a response that is proportionate, technically robust and deliverable.

Depending on the circumstances of the building, this may involve remediation, targeted intervention, mitigation or other measures. The appropriate approach will depend on the nature and significance of the identified risk, the existing construction, the characteristics of the building and the options available.

The most extensive intervention is not necessarily the most appropriate. Equally, a solution that appears simpler or less disruptive is not necessarily proportionate if it does not adequately address the identified risk.

Developing the right response therefore requires more than identifying what needs to change. It requires an understanding of what that change means for the building as a whole. 

The External Wall as a System

External walls are complex systems in which individual components and interfaces contribute to overall performance.

An intervention intended to improve fire performance can therefore introduce other technical considerations that need to be understood and managed. These wider implications can sometimes be overlooked when an external-wall issue is considered primarily through a single performance lens.

Changes to insulation, cladding, cavity barriers, membranes, openings or interfaces, for example, may affect other aspects of façade performance, including:

• Thermal performance
• Condensation and moisture risk
• Weather resistance
• Structural interfaces
• Movement and tolerances
• Durability
• Access and maintenance
• Buildability

These considerations will vary depending on the existing construction and the proposed intervention. They should not be treated as a checklist to be applied identically to every building.

The important principle is that the external wall should be considered as a system rather than a collection of independent components.

A solution that addresses one issue in isolation but creates an unacceptable consequence elsewhere does not represent a complete resolution.

Bringing Fire and Façade Engineering Together

This is where bringing fire engineering and façade engineering closer together can add significant value.

External-wall fire risk may initially be identified through a fire-focused assessment. However, developing and implementing an appropriate response requires an understanding of how that response interacts with the existing façade.

Fire engineering can help establish the nature of the fire risk and the performance requirements that need to be addressed. Façade engineering can then help determine  how those requirements can be incorporated within the existing construction while maintaining the wider performance of the external wall.

Bringing these disciplines together allows the proposed solution to be considered holistically.

Rather than asking only, “Does this address the fire risk?” The question becomes, “Does this provide an appropriate solution for the building as a whole?”

This can be particularly important where existing construction is complex, information is incomplete or interventions need to be integrated with other façade systems and building components.

Designing for Delivery

A technically appropriate solution also needs to be capable of being delivered.

Existing buildings can present significant constraints around access, sequencing, interfaces, resident considerations, procurement and programme. The proposed solution therefore needs to be considered not only in terms of its technical performance, but also how it can be implemented in practice.

This is where early coordination between the relevant disciplines can help identify constraints and potential unintended consequences before they become problems during construction.

The objective is not simply to develop a technically sound detail. It is to develop a solution that can be understood, procured, constructed and maintained within the context of the building.

Documenting the Decision

As with Identification, a strong Resolution process should leave a clear record of how decisions have been reached.

Where different approaches are available, the rationale for selecting the preferred solution should be understood and documented. This may include the risks being addressed, the options considered, the constraints identified and the reasons why the selected approach is considered appropriate.

This helps building owners move beyond simply having a recommended solution to having a defensible position around why that solution was selected.

The objective is not to eliminate every uncertainty. It is to understand the relevant uncertainties, make informed decisions and clearly document the basis for those decisions.

Resolution is Not the End

Developing the right solution is a significant step, but it is not the end of the external-wall risk journey.

The technical intent established during assessment and design needs to be carried through into delivery, with appropriate evidence demonstrating that the intended solution has been delivered as designed.

That is where Resolution begins to lead into Assurance.

A Holistic Approach at Jensen Hughes

At Jensen Hughes, our façade and fire engineering capabilities allow these considerations to be brought together within a single approach.

Rather than considering external-wall fire risk independently from the wider performance of the façade, we can bring together the relevant technical disciplines to understand the implications of different interventions and develop solutions that are appropriate to the building and the risks identified.

Our approach is therefore not simply about resolving an individual issue. It is about understanding how the proposed response works within the façade as a whole.

Identification establishes the evidence and understanding of risk.

Resolution develops the appropriate response.

Assurance demonstrates that the intended solution has been delivered and supported by appropriate evidence.

This blog is a part of a series on cladding. Read blogs the other blogs:

External Wall Risk Management for Building Owners

Understanding External-Wall Risk: What Good Identification Looks Like