A question of standards; forensic technical investigation and reporting

Carlos Turizo of HKA outlines the ground rules for instructing lawyers, clients and experts, when property damage claims rely on technical evidence.

In a dispute over damage to a building or another structure, technical experts may disagree – not only over the cause, but even the extent of the physical damage. Therefore, the facts on the ground must be measurable and comprehensible to everyone – the parties and their technical experts, insurers, insureds and brokers.

There are various reasons why these – often avoidable – conflicts over technical evidence occur. The most common factors revolve around: the importance of expert impartiality; the different technical standards that apply to designing structures and evaluating existing structures; and how the technical evidence is analysed and then reported.

Here we outline the crucial importance of each of these factors in any claim or dispute over damage, whether caused by natural events, faulty construction or design error.

THE IMPORTANCE OF EXPERT IMPARTIALITY

First, a fundamental principle not always clearly understood is that technical experts must be independent and impartial. It is common for brokers to express doubts about the independence of an expert retained by the insurance company. In turn, the insurance company may suspect that a broker’s expert is manipulating the data to get full coverage on a given claim.

Any technical expert – who respects the ethics of the role, their profession, and the value of the knowledge they have acquired over their career – must be guided only by the forensic evidence and its analysis. Conclusions reached in this way cannot be influenced by the client. When a retained expert’s opinion does not favour its client, the client should be advised on other avenues available to solve the dispute, while avoiding the cost of commissioning a full technical report.

Professionals acting as experts, drawn from academia or industry, can be technically very strong yet fail to grasp these ethical imperatives fully. They may also deviate from the standards that must be followed when gathering, evaluating and presenting technical evidence. Experts must be selected not only on their capacity to investigate the technical matters in dispute, but also on their ability to apply the appropriate standards in their analysis and reports.

QUESTIONS A TECHNICAL EXPERT MUST ANSWER

There are two essential questions the technical expert must answer: what is the extent of the damage; and what was the cause?

Disputes over damage often involve cracks in concrete or deflections on structures. Any definition of damage and its extent must determine whether the cracking or deflections are excessive or not. For example, after several months of concrete placement, it is possible for concrete to develop cracking as a result of shrinkage and temperature changes. Additionally, in a steel building, the supporting beams for a floor are horizontal, but when the contractor pours the concrete floor, the slab will deflect. The owner of the structure, the designer and contractor responsible for its construction – and their insurers – may differ on what constitutes damage. A technical expert’s opinion must be based on the appropriate standards in each of these cases.

Structural design and construction standards provide guidelines to assure the integrity and durability of a built structure by defining the specifications for materials and how they are used to support its weight and withstand external forces. Structural engineers must ensure their designs meet the safety, resistance and performance requirements of the relevant international and/or national standards and design codes.

Based on the designer’s calculations, the design may meet the code’s requirements. However, a forensic technical expert does not only take account of design and construction codes. When evaluating existing structures, other standards must also be employed, such as the ACI 562 and ASCE 41. There is a significant difference in methodology between standards for designing and measuring a built structure.

DIFFERENT STANDARDS APPLY TO DESIGN AND MEASUREMENT

Design codes and standards use factors of safety to account for the unknowns. These unknowns include variability of loads, properties of materials, and changes in dimensions that commonly occur during the construction process.

The required factors of safety used in design codes are not necessarily applicable when evaluating an existing structure. This has to do with the fact that most of the uncertainty has been removed. The properties of the existing structure can be measured. Variances in the strength of materials used can be assessed and the established geometry can be measured. Experts must then calculate the actual, as opposed to the theoretical, loads experienced within the structure. For example, we have seen experts incorrectly use allowable deflections defined in design standards to evaluate measured deflections on existing buildings.

Various codes set limits for serviceability acceptance criteria. One of these limits relates to allowable deflections within structures. The standards set by the ASCE (American Society of Civil Engineers), for example, are widely used not only in the US but internationally. Initially, the ASCE standard specified a total value for the allowable deflection. It was then agreed upon that one limit could not cover all scenarios. The ASCE-7 is a modified standard that includes the evaluation of serviceability of a structure by stating that it refers to a structure’s ability to function as intended, avoiding excessive deformation, vibration or deterioration that could disrupt its use or cause occupant discomfort. In other words, when a structure’s functionality is impaired by the deflections, then this can be considered damage.

HOW TECHNICAL EVIDENCE IS ANALYSED AND REPORTED  

Another potential pitfall lies in how technical analysis is conducted and how it is reported. Standards of best practice must apply.

When evaluating technical data, experts must follow the scientific method. This is set out in a previous standard called the US ASTM E678 standard. Although this standard was withdrawn three years ago, the scientific principles it outlined are still widely accepted by the technical expert community. Instead of a direct replacement, guidance on evaluating scientific or technical data in forensic investigation can now be found in the US ASTM E1188 and E1020.  

Within the US ASTM E678 standard, there are six essential steps detailed as follows: identify the problem; perform inspections, to include gathering measurements and other supporting data such as photographs and aerial or satellite images; generate hypotheses for the potential causes of the damage, which could be extreme rainfall or other weather events or errors in construction and/or design; evaluate each hypothesis in turn, experimenting as necessary – by testing sample materials in a laboratory, computer modelling and/or load testing; analyse all the resultant data to determine which hypotheses can be eliminated and which are valid; and draw final conclusions. These findings provide a solid evidence-based foundation for the expert’s opinion.

Having followed a scientific process in evaluating the data, this approach should be reflected in the final product – the technical report. Experts often ignore the value of analysing and considering alternative hypotheses to determine the cause of the damage. In such cases, reports are centred on the expert’s opinions, which could be interpreted as partiality in favour of the expert’s client.

CONCLUSION

It is important that clients receiving a report confirm that it has followed standard practice for reporting the opinions of scientific or technical experts. The ASTM E620 standard, for example, outlines the essential elements and structure of a technical report. Its aims are to ensure the recipient will understand the report and that its technical aspects are relevant and focused on its intended purpose.

A technical report starts with a brief description of what is being analysed. It then describes the methods used to investigate the different issues, clearly defining the problems. Additionally, the competing claims and relationship of the parties in dispute must be set out. Each plausible hypothesis must be examined and evaluated. Finally, the expert reaches a conclusion based on analysis of his respective data.

A well-structured report provides clarity about the topic at hand and takes its audience into account. Claims handlers, insurance companies and lawyers, while experts in their respective fields, have limited basic knowledge on technical matters. Therefore, technical experts need to practice and develop the writing skills necessary to provide a concise and clear technical opinion for the reader at hand. Experts have a responsibility to their audience to concisely explain the rationale and logic used in arriving at each conclusion in their reports. 

Carlos Turizo is a professional engineer and director at HKA in New York.