Why the difficulty estimating the cost of forensic engineering investigation?

Why indeed?

You’re the expert and should know how to accurately estimate the cost of your work, you say.  But we don’t know in every instance, and for every investigation and task.  We know a lot in our respective fields but we don’t know it all.  There are just too many unknowns.

Similar, would be counsel’s difficulty estimating the cost of the role of the expert at the different stages of the civil litigation process (Ref. 3 and 5 to 14).  These costs are quite separate from the cost of the steps in the forensic engineering investigative process.

Summary of reasons for the difficulty estimating costs

Accurately estimating the cost of forensic engineering investigation is difficult because:

1. Identifying all the investigative tasks at the start of the process is difficult, occasionally impossible:

  • The tasks that must be completed in the standard investigative process. (Ref. 4)  Sometimes all of them.  Sometimes we find we can skip some.
  • The unknown follow-up investigations that must be carried out

2. The unknown magnitude and complexity of some of these investigations and tasks

3. The possibility of changed conditions.  For example, in the office, an unknown research question or, in the field, changed foundation soil conditions.

4. Some tasks depend on the data from previous tasks and we don’t know the nature of that data until we gather it.

5. Some investigations and tasks are carried out well in the future when circumstances may have changed.

Detailed explanation of the reasons for the difficulty estimating costs 

The following is a detailed explanation of why we have difficulty accurately estimating the cost of each task in a forensic engineering investigation.  I have included some examples in the following.  There are other examples in the Appendix.

The main reasons are in a bulleted list.  I elaborate a little on the list in accompanying text.

The explanation is based on my engineering experience investigating the cause of failures in the built and natural environments, and the cause of accidents resulting in property damage, personal injury, and/or death.  My experience is in Atlantic Canada, northern and western Canada, the Caribbean, and overseas in Australia and the U.K.

Previous blogs described the different steps in a forensic engineering investigation (Ref. 4) and the degree of difficulty estimating their cost (Ref. 15).

The main sections in the following, 1., 2., 3…, are the main tasks in a forensic engineering investigation The sub-sections, 2.1, 2.2, 2.3…, are a breakdown of these tasks.

1. Document review


It’s easy to accurately estimate the cost of this initial task because:

  • You have the documents in front of you
  • For a simple reading, you count the pages, calculate time based on your reading rate, and multiply by the appropriate fee to get a quite accurate estimate of cost
  • Actually studying the documents, abstracting data, and making notes adds difficulty to the estimating but it’s still relatively easy

Estimating the cost of this initial step in the process is easy because you have the documents in front of you - they have been given to you by counsel.

For a simple reading you can count the pages and estimate time according to your reading rate.  Then apply the appropriate fee to get an estimated cost.

Actually studying the documents – as compared to a simple reading - abstracting data, and making notes would add a level of difficulty to accurately estimating costs.  Still, this step is relatively easy.

For example, I recently read the documents on an accident.  They consisted of the lengthy transcripts of the testimony of the three parties involved.  I read them to get a feel for the situation preparatory to a possible site visit.  Two transcripts were easy to read.  One was difficult which reduced the accuracy of my cost estimate a little - a difficulty I did not know about at the start, but still the estimating was fairly easy.  

2. Visual assessment

A visual assessment can involve the following three main tasks:

2.1 Visit and visually assess site

Fairly easy

Accurately estimating the cost of this task is fairly easy because:

  • You know the location of the failure or accident site and the time to get there
  • All you’re going to do is walk around the site – kick the tires in a sense, poke around a bit, and pick up general impressions and make notes on future tasks
  • While a catastrophic failure adds difficulty, you can still schedule a few hours initially and estimate costs for this time – and schedule a more detailed, follow-up visit and visual assessment if necessary

Estimating the cost of this task is fairly easy because you know where the site is located and the time to get there.  You also know you are simply walking around and looking – picking up visual impressions, making notes on what you’re seeing, and identifying future tasks.  There is some difficulty because you don’t always know what you’re going to see, particularly with a catastrophic failure.

2.2 Photograph and videotape site

Fairly easy

Estimating the cost of this task is fairly easy because:

  • The general intent of the photographs is to refresh the memory of what was seen
  • Simple distance and middle-distance photographs/video achieve the purpose
  • While labelling the photographs adds difficulty – it actually adds the difficulty to the easy photographing, it doesn’t take so much from the fairly easy cost estimating of this task

This task is also fairly easy to estimate particularly when the type of photograph/video is distant and middle distant, rather than a lot of close-ups, and the intent of the photographs is to refresh the memory of what was seen.

There’s difficulty, however, when labelling the photographs, putting captions on them.  These must be carefully and accurately worded in a forensic investigation and that takes time – the picture may become an important document at a later date.

2.3 Interview witnesses


Accurately estimating the cost of this task is difficult because:

  • You don’t know how many witnesses there will be
  • Nor the amount of time needed to locate the witnesses
  • Or the duration of the interviews

The difficulty estimating the cost of this task is real easy to understand.  It’s difficult because you don’t know how many witnesses there will be, the difficulty locating them, and the duration of the interviews.

3. Field investigations

Any number of different field investigations might be carried out depending on what failed and how – inadequate performance of a structure, a damaged but still serviceable structure, or complete collapse of a structure, or the type of accident that occurred.  The following investigations are an almost certain requirement:

3.1 Describe the failure or accident

Fairly easy

Estimating the cost of this task is fairly easy because:

  • The documents usually contain a description that you can simply read
  • Confirming the description in the field and taking a few measurements doesn’t greatly affect the difficulty of estimating the cost of this task

The documents usually contain a description, so, you would just read the existing description.  This means estimating the cost of this investigation would be fairly easy.  However, the description must be confirmed in the field and add detail by examining the failed structure further.  Some measurements might be taken.

3.2 Survey and document damage to the structure

Fairly difficult

Accurately estimating the cost of this investigation is fairly difficult because:

  • It often involves taking a lot of measurements and carefully plotting the data
  • This takes time and you don’t know what you got on your hands until you get into it

It is fairly difficult to estimate the cost of this investigation because it often involves a lot of measuring then plotting the data.  This takes time and you don’t know what you’ve got on your hands until you get into it.

Carefully plotting the data is often quite important in a foundation failure where the structure is damaged but hasn’t collapsed completely.

For example, the plot can quantify and characterize the magnitude and location of the damage, particularly if the latter is only slight.  The plot sometimes can actually give an indication of the cause of the failure.

3.3 Determine how the structure was built

Easy to difficult

The effort in estimating the cost of this task can be quite variable, from easy to difficult, because:

  • The estimating depends on the availability of construction or as-built drawings – easy to estimate if available, difficult if not
  • It also depends on the age of the structure – difficult because of the unlikely availability of drawings for old structures, a little easier if drawings exist for an old structure
  • And, if drawings are available, whether or not the new or old structure was erected according to the drawings

Estimating the cost of this task is easy, if there are construction or as-built drawings available.  You gather the drawings together and have them readily available for reference during the analysis of the cause of the failure.

The estimating gets difficult if there are no drawings or if the structure is old.  It’s also difficult if the structure is said to be constructed one way and turns out to be different.

For example, – this is quite an example - I investigated the construction of a structure one time that was said to be uniformly supported on a concrete floor slab.  It was also said to have been temporarily supported on concrete columns on a five foot grid during underpinning work.  The cost estimate here would seem to be for a simple confirmation of what was said to be case.

Problems started as soon as a precise elevation survey found the supposedly level structure was sloping and off level by one foot from one end to the other.  Turns out - well along in the forensic engineering investigation, that it had been built that way.

Then it was found that the columns were separated at random distances of two to seven feet rather than on a five foot grid.  And that some of the columns were steel jack-posts, and that some of these were supported on rotting timber.

Finally, it was found that the ‘temporary’ columns were actually the permanent support of the structure, and that it was not a uniformly supported concrete floor slab - information that guided the original cost estimate.

Needless to say, my cost estimate to investigate construction of this structure was very inaccurate.

3.4 Determine the site conditions

Very difficult

Estimating the cost of this investigation is very difficult because:

  • At best, you only have the most general understanding of what you might find - what you are investigating.  That is because most of it – the most important part of it, lies below the ground surface out of sight

Estimating this cost is very difficult because site conditions include, in addition to the surface terrain, which you can see, the nature and condition of the underlying soils, rocks, and groundwater, which you can’t see.

How do you estimate the cost of investigating something the nature of which you can’t see?  Except to know a little in the most general way based on published information.

4. Laboratory investigations

Very difficult

It’s very difficult to estimate the cost of these investigations because:

  • Laboratory testing – the number and the kinds of tests, is very dependant on the findings of previous investigations
  • You don’t know the different kinds of materials you will be testing, the type of tests you will be doing, and the physical properties in which you will be interested

These investigations are very difficult to estimate costs for because they depend on the findings – the evidence from your previous investigations, particularly materials from the damaged structure and the terrain beyond.

5. Research

Research can involve a lot of investigative work the nature of much of which just wouldn’t be known until other investigations are completed.  Hence estimating research costs at the start of a forensic engineering investigation is generally difficult.

A lot of the unknown investigative work would fall under the catch-all task of desk studies.  The need to research the codes and the standard of care in connection with an engineering failure or an accident is an almost certain requirement.

5.1 Desk studies and leg work


It’s difficult to estimate the cost of these studies because:

  • You just don’t know what the unknown studies are until you are well along in the forensic investigation, or, if you do know certain standard studies will arise, you might not know their particular magnitude or complexity

The cost of these studies is difficult to estimate because in some cases you just don’t know what they are until you are well along in a forensic engineering investigation.  Or if you know that a certain study will follow from previous investigations – certain standard follow-up studies, you may not know the magnitude or complexity of the particular study.

For example, I found during one case that I had to investigate the shrinkage and fluid properties of a construction material used in the underpinning of a structure.  This involved literature and internet searches – desk studies, and interviewing suppliers of the material – leg work.  I did not know there was such a material at the start of the forensic investigation.

5.2 Identify codes

Fairly difficult

It’s difficult to estimate the cost to identify codes and guidelines because:

  • While we know or suspect the existence of certain standard codes, we can’t assume we know about all the relevant guidelines, which are different from codes

Estimating the cost to identify and study the applicable codes and guidelines is fairly difficult, particularly guidelines.  Codes we know about; they’re usually issued by national and provincial bodies and large organizations.  Useful guidelines are less well known and can vary for different components of a structure, therefore difficult to estimate costs to identify.

5.3 Identify standard of care

Fairly difficult to very difficult

To summarize, estimating the cost to assess the standard of care can be difficult because:

  • You don’t know at the start of an investigation if the industry involved in development of the structure or component that failed is well defined or not, how many parties comprise the industry, and how many interviews are needed to be satisfied about average practice
  • If you do know – like the design and construction of conventional buildings, it might almost be fairly easy

The difficulty in estimating the cost to identify the standard of care is closely related to how well defined the industry is that developed the structure, or the component that failed or didn’t perform as required, and how many parties comprise the industry.

Assessing the standard of care involves gaining a very good understanding of the industry, the parties comprising the industry, and how they interact and work together.  Difficult sometimes, easy other times.

For example, sometimes it’s fairly easy to estimate costs as in the case of the design and construction industry.

Then once you know the industry, identifying the standard of care involves interviewing representatives of the different parties involved in the industry and in development of the structure or component that failed, as to their work practices.  You interview until you feel satisfied you understand the average practice (Ref. 16) for each party and from that the average practice for the industry as a whole – the standard of care.

Sometimes it’s difficult to estimate costs as in a poorly defined industry.  How such an industry works only comes into focus after you interview a number of representatives of different parties that seem to have a role in the industry.

For example, I assessed the standard of care in one case earlier this year.  I soon learned that the industry was poorly defined resulting in the difficulty outlined above.  At one point, I identified 11 parties comprising this industry.  In addition, there were a number of codes and guidelines to be assessed as to their relevancy.

Interviewing one to three representatives of each party resulted in 15 to 20 interviews and e-mail enquiries in an effort to be satisfied I understood how the industry worked and its average practice.  It’s very difficult to accurately estimate the cost to assess the standard of care in a situation like this.

6. Follow-up investigations 


It’s impossible to estimate the cost of follow-up investigations because:

  • The nature and the number of follow-up investigations is just not known at the start of a forensic engineering investigation.  For that matter, whether or not there will even be a need for such investigations

It’s impossible to estimate the cost of follow-up investigations because we don’t know what they are – what evidence we may need to follow, until we are well into the forensic engineering investigation.

7. Data analysis and forming an opinion 

Very difficult

To summarize, it is very difficult to estimate the cost of this task because:

  • You don’t know at the start of a forensic investigation how much data you will have to analyse
  • Nor do you know it’s nature – the kind of data, and its complexity
  • Or the amount of reasoning, crosschecking, and corroboration required
  • Nor even if another visit to the site is necessary
  • At the start of an investigation, you just don’t know how many hours, days, possibly even weeks will be required for the analysis

The cost of this task is very difficult to estimate because you just don’t know at the start of a forensic engineering investigation how much data you’ve got to study, it’s nature, and it’s complexity.  Nor how much reasoning, cross checking, and corroboration you’ve got to do.

Sometimes at this late stage of an investigation it may be necessary to go back to the site and check one thing or another.  Depending on the nature of the failure or accident the data analysis could take hours, days, maybe even weeks.

8. Repair and remediation 


It’s difficult to estimate the cost of repair and remediation because:

  • You don’t know the cause of the failure at the start of a forensic engineering investigation when you’re estimating costs
  • Fixing the unknown cause is part of the cost of repair and remediation

You can’t fix something until you know what’s wrong with it and why making it difficult to accurately estimate costs at the start of an investigation.  This is particularly the case for a foundation failure where the unknown cause often lies below the ground surface.  You can’t see and don’t know what’s below the ground surface at the cost estimating stage at the start of a forensic investigation.

9. Report


It’s difficult to accurately estimate the cost of a forensic report because:

  • While it can be a bit mechanical – fairly easy, writing a simple report, it can be difficult if there is a lot of data to gather together, tabulate, and analyse
  • Estimating the cost of a report can be particularly difficult if there is a lot of data to actually plot, drawings to produce, and graphics to include and label with accurately worded captions
  • Involved analysis can be difficult to describe in simple terms
  • The data from unexpected follow-up investigations needs to be reported and analysed
  • Unexpected evidence (‘follow the evidence’) must be reported and analysed

It’s difficult but not impossible to estimate the cost of writing a report on the forensic investigation, before the investigation has been carried out.

The report describes what has been done, gathers together from the file and reports the data, describes the analysis of the data, notes the conclusions, and states the opinion.  To some extent it’s a bit mechanical.

It gets difficult to estimate costs when there is a lot of data to tabulate, plot, and describe in a report.  This can reduce the accuracy of the cost estimate.

Describing an involved and difficult analysis in easily understood terms can be time consuming – an involved analysis not anticipated at the start and allowed for in the cost estimate.

Unknown follow up investigations, and evidence that leads off in unexpected directions, can also add to the estimated cost of writing a forensic report.


The foregoing assessment of difficulty was taken from a posting to this blog site on July 15, 2013 entitled, “Steps in the forensic engineering investigative process with an Appendix on costs”.


  1. What is forensic engineering?, published, November 20, 2012
  2. Writing forensic engineering reports, published, November 6, 2012
  3. Steps in the civil litigation process, published, August 28, 2012
  4. Steps in the forensic engineering investigative process with an Appendix on costs, published July 15, 2013
  5. The role of a professional engineer in counsel’s decision to take a case, published June 26, 2012
  6. The role of a professional engineer assisting counsel prepare a Notice of Claim, published July 26, 2012
  7. The role of a professional engineer assisting counsel prepare a Statement of Claim, published September 11, 2012
  8. The role of a professional engineer assisting counsel prepare a Statement of Defence, published September 26, 2012
  9. The role of a professional engineer assisting counsel prepare an Affidavit of Documents, published October 4, 2012
  10. The role of a professional engineer assisting counsel during Discovery, published October 16, 2012
  11. The role of a professional engineer assisting counsel during Alternate Dispute Resolution (ADR), published November 16, 2012
  12. The role of a professional engineer assisting counsel prepare for a Settlement Conference, published November 29, 2012
  13. The role of a professional engineer assisting counsel prepare for a Trial Date Assignment Conference, published December 12, 2012
  14. The role of a professional engineer assisting counsel prepare for Trial, published, December 19, 2012
  15. Difficulty estimating the cost of forensic engineering investigation, published July 23 2013
  16. ASFE, Expert: A guide to forensic engineering and service as an expert witness, Association of Soil and Foundation Engineers 1985


We have our standard investigative protocols for guidance when estimating costs but we know we may end up skipping tasks or adding follow-up tasks.

Some examples

For example, in an alleged major flooding problem I skipped from an oral briefing of the problem to a visual assessment on site to an oral report on my findings, that brought an expensive case by others to a quick close.

We also know that a standard task in a forensic investigation may take on a quite unsuspecting magnitude and/or complexity.

For example, assessing the standard of care to do with a matter in the built environment can be fairly straightforward – you identify the usually few parties involved – the designers and construction people, and interview them.

But what happens if you gradually learn that a certain industry is poorly defined and there are maybe a dozen or so parties involved in the task for which the standard of care is being assessed and you must interview two or three from each party to get an average?  Then estimating the cost of doing this is difficult, particularly at the start when you didn’t know the industry was poorly defined and made up of so many parties.

We also know that the evidence – if we follow it - a follow-up investigation - may take us down an unknown path to an unknown task.

For example, I found myself in one case needing to determine the physical properties of a quite different construction material, one used infrequently in Atlantic Canada.  But as it turned out a material extremely relevant to the cause of a construction problem.  This was a cost I had no idea I would have to incur on behalf of the client, the plaintiff in this particular case.


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