Principal Design Consultant
Darren Barker has over 32 years’ experience in the construction industry in civil engineering. He began his career as an apprentice in the days of drawing boards and pencils, before working on the original CrossRail scheme in the 1990’s. He went on to become an early adopter of BIM delivery on projects such as Msherieb Station on the Doha Metro and Victoria Station Upgrade, most recently leading BIM delivery of High Speed 2 Area North.
His expertise in standardisation and compliance led to the development of a common level of detail (LOD) on HS2 Area North. Following the significant measurable benefits this is delivering, Darren is focused on sharing this story with the aim of driving the use of this approach on all future transportation projects.
What to expect during the event
As defined in ISO 19650, a set of clear definitions for information on a project is required in order to work efficiently. Justifying these information needs without providing too much or too little detail drives productivity and allows us to make informed decisions. This means defining the LOD and the component catalogues in advance.
As such, we consider the component catalogue to be a key deliverable which defines the graphical and non-graphical content of each object, covering all disciplines.
Although the definition of LOD is open to interpretation, it is generally based on client or owner/operator requirements, which can lead to fluidity in the actual detail. Simply relying on LOD200 or LOD300, for example, has been insufficient in the past and standards such as those set by the American Institute of Architects (AIA) are too generic. Not developing the appropriate LOD at the outset of a project will likely lead to dispute and surprise during delivery.
Using the NBS Toolkit as a baseline, it’s clear that while the industry is still becoming familiar with the LOD concept, a sufficiently detailed LOD description for each stage of a project which avoids later arguments has not been fully developed. In addition, it is critical the end user creates or approves this information standard so only the required information is produced.
In establishing a common LOD, how can we ensure our 3D models are compliant? Visual checks on each component are virtually impossible to police, so how we can automate this process?
Using the LOD definitions and creating a machine-readable data schema from these requirements allows each model to be automatically checked and assured. This gives the designer and client full visibility of the information within the models and allows the author to prove compliance with the LOD.
Giving insights to the whole team on our performance using Power BI dashboards provides full exposure to the quality of the data. Highlighting non-compliance early allows corrections to be made.
Deploying these checks within the production team removes any ambiguity regarding compliance. This wouldn’t have been possible without a clear LOD.
Identifying and applying best practice on projects unlocks a huge increase in efficiency. Defining objects that would historically be modelled from scratch each time promotes consistency – and most importantly, saves valuable time.
By utilising the Moata Component Centre, one of the suite of tools in Mott MacDonald’s digital platform, we can standardise how projects are modelled and add defined LOD information.
This enables us to create a library of 3D objects that can be placed directly from the library into the design models. Although a fair amount of time is needed upfront to produce the objects, the return on investment is huge.
Building in parametric functions and constraints into these objects allows the author to input desired measurements without having to manually ‘stretch’ the object. Automated reporting tools, based on the object’s parameters, allows the schedule to be exported directly from the 3D model to the drawings.
Standardisation across projects relies on author ownership and utilisation of standard processes. Without their interaction with this process, the overall benefits of the approach are reduced.
We deployed a standard naming convention within the objects to define whether or not it was placed from the component centrelibrary. Like the data completeness dashboards, this gives us insights into where these have been used. Take a bridge, for example – if the beams and parapets have been modelled using different methods then this would be a deemed as non-compliant and noted in the dashboards, requiring the object to be remodelled.
Integration of Safetiibase
SafetiIbase is an award-winning system to improve the identification, management and communication of health and safety hazards for construction projects. Funded by i3P, it is an open-source solution for the industry.
Capturing safety data in a structured manner allows us to visualise this information in our 3D models. However, we needed to take this a step further and extract this data directly to the drawings.
By placing an export function in Safetibase, this information can now be published to a text file, which is imported into the drawings, ensuring consistency between Safetibase and the final drawing output.
This gives the end user full control and clarity over which risks need to be displayed on the drawings. The unique risk number and description are unique, so anyone using Safetibase, the 3D model or the drawings knows they are all aligned.
In a digital world we all follow standards such as ISO 19650, but why is the LOD not actually precisely defined precisely? Concepts and principles on how to develop the LOD are described without any ‘real’ detail. And dDoes anyone really know what LOD 400 means? Simply having a colourful model on the screen doesn’t mean you have achieved thisit. The key thing is that it’s all about the end user of the information. How do we involve them in the creation of the standard at the outset?
As an industry we are advancing our approach to standardisation, but there are a number of different standards available. The National Bureau of Standards (NBS) has created the NBS BIM Toolkit, Building Smart has created a data dictionary, and ISO-19650 Part D talks about ‘under -definition’ and ‘over definition’. Doesn’t Tthis all leads to non-standardisation and multiple interpretations. ?
With the UK government’s commitment to achieving net-zero, how can we help develop a standard approach to LOD? The focus must be on pre-construction activities, which disproportionally lead to construction waste and inefficiencies.
The opportunity to remove ambiguity and aspire to a consistent approach of to LOD ensures this information can be provided in a human readable format long before construction commences, which can influence early decision- making.
With all of this in mind, perhaps do we have too many organisations collaborating on information standards.?
Let’s get the basics right first. If LOD 400 were so explicitly defined that there was no opportunity for dispute, what benefits could that bring to a project? I think it’s clear apparent by now that more clearly defining the LOD from the outset will bring better outcomes to clients and the customers they serve.