Engaging Structural Engineers in the BIM Process

“………….. engineers work under a fairly structured environment, both in term of organisational structure and workflow….”

This is a sentiment that I have heard from architects again and again in Building Information Modelling case studies and presentations. It is basically a nice way of saying the traditional division of tasks in structural engineering offices is preventing the designs of senior engineer staff from being represented in the model at the appropriate time.

Seven or 8 years ago the same comment would have been would have been true about architectural firms. Senior staff weren’t able to interrogate or add to models, which meant that their ideas weren’t represented in the model in the early stages of design. This meant that the whole concept of the MacLeamy Curve was rendered useless. The design process wasn’t being shifted to an earlier phase, all that was happening was that junior staff were spending a lot of early time on projects, injecting their inexperience into the design, before senior staff produced their more thorough design at the same time as usual.


It became apparent, even from outside these companies that some senior staff were being ‘cut out’ of their own internal review process.

These days things have changed, the junior and mid-level architects who became involved with Building Information Modelling 10 years ago now hold senior design positions, and unlike almost every other industry, architectural firms actually laid off some senior staff who were unable to ‘digitally contribute’ post-global financial crisis.

Change of any sort is often unwelcome in Engineering offices, any shirt that is not vertical blue strips is often seen as radical and subversive.  BrisBim (Brisbane’s Building Information Modelling Forum) is currently running a Poll at the moment to see ‘who on your project team has the most positive approach to BIM?’ last time I checked Structural Engineer had two votes.

There are definitely some exceptions to this rule, in Australia and overseas several prominent Engineers have become heavily involved in Building Information Modelling, both technically and as lobbyists for BIM legislation.

The industry best practice is for engineering design and analysis models to be fully integrated with building information models using software such as ETABS or Robot Structural Analysis, where preliminary models are exported from the design software to Revit Structure and then imported back at regular intervals.

What is the ‘plan B’ when this is not possible due to financial, technical or organizational culture limitations? Here are some ideas to get engineers to dip their toes in the water and break down the division between modellers and engineers:

  • Export some simple schedules from Revit to Microsoft Access. The Engineer can easily update some framing sizes or preliminary reinforcement rates. These can then be imported back into the model
  • Involve the engineer in designing complex bespoke elements of the building in Rhinoceros and Grasshopper, these elements can be exported to space gas or strand for structural analysis. The principal is the same as using ETABS or Robot Analysis but the scope is limited to several smaller elements within the building. These bespoke elements can be exported to your building model as SAT. files.
  • Involve the Engineer in the Navisworks or Solibri clash detection process. The best person to decide if a beam penetration is advisable is a structural engineer.


All these strategies are entirely voluntary, however it is worth noting that when your company signs up to the BIM execution plan you are making a commitment to providing a model that contains additional information to the construction drawings.  In Australia at least this means the Structural Engineer is legally bound to conduct a comprehensive model review at crucial points of the documentation process.  This is the unavoidable minimum requirement for all Engineers on Building Information Modelling projects.

The opinions expressed herein are my own personal opinions and do not represent my employer’s view in any way. Also – Anything that mentions AutoCAD, NAVISWORKS or REVIT or any other Autodesk product is a registered Trademark of Autodesk.


Revit Structure to Robot Analysis


Analysis in Revit Structure using Robot Analysis


Revit Structure to Robot Analysis




Rhinoceros 3D modelling software to Revit


Understanding the MacLeamy Curve


Why a good BIM Statment can make a difference

What is a Building Information Modelling statement? Is it just a list of capabilities and some marketing material to let other firms know what you can do or is it something more?

A BIM statement refers to a company’s future planning and culture. Unlike BIM Execution Plans, BIM statements are poorly understood. BIM Execution Plans have been refined over time, there are some excellent templates out there for small, time poor firms. Natspec is the obvious example. BIM Execution Plans apply to individual projects. However a good BIM Statement, can be more important than an execution plan because it locks in BIM to the ‘DNA’ of a firm.

The last 10 years have shown us that firms who haven’t approached Building Information Modelling in a thorough way haven’t got very far.

“many users become ‘partial adopters’. BIM becomes a way of exploring in 3D for design only and real documentation is still done in the traditional way. In our experience these users have a short lifespan as eventually projects arise which demand a fully integrated workflow. In these circumstances it pays to be the firm who has adopted BIM as an integral way of working as the firm with the most skills tends to set the rules.”

Stewart Caldwell, Russell and Yelland Architects and  Michael Clothier, Walbridge and Gilbert Engineers

Making sure this implementation is thorough is why BIM statements are important and can be crucial in:

  • Making sure that the organisation is working to a long-term plan
  • Making sure employees understand the plan
  • Making sure Clients, and other consultants understand the plan

In my opinion a BIM Statement should be a set of values and goals, mapping out a company’s direction in the years to come, similar in tone to an equal opportunity statement,  or a statement of corporate responsibility. Would you be more likely to believe a firm that claimed they could deliver everything now, or a firm that aimed to deliver LOD 300 Building Models now, with modelled earth works in two more years and underground services in the year after that with LOD 400 live collaborative models being delivered soon after?.

Autodesk released a set of documents called a ‘BIM Deployment package’, which I guess is what you would expect from a software company, in their minds changing organizational culture is like slipping a USB into the back of some ones head. There is however lots of useful information in this package, and instead or referring to a ‘BIM Statement’ they use the term ‘BIM Vision Statement’ which is a lot more descriptive and clears up some of the confusion.

“Your BIM vision is the first thing prospective and/or existing clients will see. In addition to aligning with your overall business model, it will need to be real.”


The following is an extract from the American Department of Veterans Affairs Building information Vision Statement:

“………. conversion to BIM is to deliver higher value and maximize life-cycle building performance to support VA’s mission to deliver excellent medical services. Just as the VA’s digitization of patient records has greatly improved the business and management process of care delivery for patients, so the digitization of building data will improve the design and management of VA
buildings across their life-cycle”

The statement mentions future goals, and ties these goal to the central focus of the organisation.

In summary, get it right and you will build long-term relationships with your clients, get it wrong and clients will smell ‘BIM Wash’ (refer below) and be unwilling to enter into long term relationships.





The opinions expressed herein are my own personal opinions and do not represent my employer’s view in any way. Also – Anything that mentions AutoCAD, NAVISWORKS or REVIT or any other Autodesk product is a registered Trademark of Autodesk.

Reinforcement: Data versus BIM Dogma

Why do we model steel reinforcement? I think it is a classic case of ‘rendered image fixation’ where Consulting Engineers or Architects forget about the “Information” in Building Information Modelling.

I have been helping people to learn Revit for the last 8 years, and almost invariably the first thing a new user does is to forget all about the company modelling matrix, and any previous instructions about Level of Development (LOD), and try to model an item in the project that is outside the firm’s scope of works in intense geometric detail (usually with no embedded data). Reinforcement modelling seems to be part of the same problem on a bigger scale.


It is a useful exercise to refocus on the bigger picture. Concrete Reinforcement may not be everyone’s idea of an exciting topic, but it helps us understand the question of why are we doing BIM?

Building Information Modelling has multiple aims including:

  1. To assist with facilities management
  2. To assist with costing
  3. To assist with project management and phasing
  4. To assist with clash detection
  5. To produce integrated documentation

Building Information Modelling Execution Plans often specify that reinforcement needs to be modelled, but no one seems to know why. Steel fixers interpret the structural engineer’s drawings on site, and set out the reinforcement by quick and approximate measurements, checking (hopefully) as they go that they haven’t exceeded the engineers required spacing. There is no guarantee that reinforcement will end up exactly where it was modelled (unlike steel framing elements). The only exception would be welded reinforcement cages.

Modelled reinforcement won’t help with clash detection, because you can’t be 100% sure precisely where the reinforcement will sit. It won’t help with retro-fitting penetrations to slabs and walls for the same reason. Concrete X-Rays would still be required for establishing precise reinforcement locations.

Costing is probably the greatest potential use for modelled reinforcement. Quantity Surveyors (QS) can use the models to produce more accurate cost estimates. My question is, would the cost estimate be more accurate if we used the data from the model instead of just the geometry? Modelling of reinforcement is labour intensive, reinforcement laps are not often modelled correctly, and slab mesh laps are never modelled correctly, so the QS still has a bit of work to do. The spacing of beam and column ligatures and ties are never simple and usually change spacing towards the top of the column and the end of the beam.  This set out gets even more complicated in earth quake zones.

The best Building Information Modelling solution for the costing of reinforcement and facilities management is embedded data within all concrete elements. The column shown below has parameters for the vertical reinforcement, ligatures, ties, connections at the top and base, a reference to a section of the column and a reinforcement rate. Once you combine this with the volume of all similar columns within the building, which can be easily calculated using the model parameters, the QS should be able to efficiently estimate the cost of the reinforcement required.

Column Reo

These issues don’t just occur in Structural Engineering. Architects and in particular Interior designers often achieve excellent results by using embedded data over detailed geometry. Please note the examples I have given are from my own experience of reinforced concrete in Australia. The approach to concrete reinforcement, reinforcement scheduling and reinforcement detailing in the U.K and the U.S. are completely different.

I am more than happy to be proved wrong on this issue. If you work for a Quantity Surveyor or you schedule reinforcement for a living and find modelled reinforcement useful let me know.

Links for understanding LOD and facilities management



The views expressed in this blog are not necessarily those of my employer.

BIM, Structural Engineering and the Digital Divide

Any conversation with a Structural Engineer about Building Information Modelling is an odd experience.  They will either tell you it is the best thing to happen to the industry in years, or that it simply doesn’t happen and doesn’t exist. The answer is either yes or no, black or white. Comments like “we tried it once and it doesn’t work” are not uncommon.

A conversation with an architect would be somewhat different. A lot of architecture firms have a BIM statement which locks them into steady progress, they may not be setting the world alight now but they plan to be in a few years. There are many one person firms doing a great job of documenting houses using 3D models with embedded data. The point is most firms have their toe in the water to some extent. To architects the question of BIM is a graded scale. They see themselves as all involved in some form of BIM, the only difference is the extent of that commitment

This ‘yes or no’ attitude of Structural Engineers is having a polarising effect on the industry. There are a group of large and medium-sized firms who dominate the BIM niche market. They share some of the characteristics listed below


Characteristics of BIM capable Structural Engineering firms

  • A high percentage of government clients or large-scale projects
  • Transition to Revit® occurred pre-global financial crisis
  • The modelling occurs using multiple software platforms (for example Revit®, Tekla Structures and Navisworks®)  that are constantly changing
  • Highly skilled Employees
  • Low level of staff turnover
  • Often multi-disciplinary firms
  • Building modellers are engaged with architects and clients
  • Engineers and Modellers collaborate well
  • Building Modellers are perceived as adding value to projects
  • Fees and wages tend to be higher than average

The rest of the market seems to be headed in an entirely different direction.

Old drafting

Characteristics of Structural Engineering firms with no BIM capacity

  • Software tends to be several years old
  • The software that is used is not used to not used to its maximum capacity
  • Smaller commercial, residential and industrial projects
  • Higher staff turnover
  • Drafting is perceived as unskilled labour and a cost to be minimised
  • Minimal staff training
  • Lower than average fees and wages

While Building Information Modelling firms are no magical paradise, the trend is concerning. Would potential employees who had always worked outside the BIM community be able to get up to speed in less than two years? Would an engineer who had never used ETABS or Robot Analysis with Revit be able to step straight into a new project with minimal training?. The point is that the actual positions are so different, it is increasingly hard to move between the two worlds. There has been a 10 year conversation about legal issues, collaboration and level of detail, to name but a few issues, and it is difficult to enter that conversation and put those issues in context.

As the market slows down we can expect small to medium-sized consulting engineers to invest less in software, training and staff retention. Which leads to a vicious circle, the less you invest in these things, the less capable you are of landing a large project which could lead to increased profits, which could be invested in staff training and software.

Consulting engineering is a service industry. The best way to thrive long-term in such an industry is to provide the highest quality of service possible. Providing a low-cost, basic level of service may lead to short-term profits, but eventually those firms will lose out to the low-cost, basic service offered by offshore firms, who will always win any price war.

All is not lost for the ‘digital have-nots’. Firstly the current level of unemployment in the construction industry has seen many skilled engineers and modelling staff out of work. These people will eventually find employment with the digital ‘have-nots’, seeding their new ideas with their new employers. Secondly Australia must follow The United Kingdom’s and Singapore’s lead and pass Building Information Modelling legislation. Such laws (with a lengthy lead in time) would still deliver most of the pie to the BIM capable firms, but they would also deliver certainty to the industry and create a sense of urgency in the medium-sized firms that are in danger of being frozen out of a lucrative portion of the market.






The views expressed in this blog are not necessarily those of my employer.