For many years now LOD - be it Level of Detail, Level of Definition, Level of Development or another term, has been an important but badly defined term in the work of digital transformation in the UK construction industry. Level of Definition, a UK specific term published in BS1192 created much debate in the industry as to how it should be interpreted. Â
But now, with the publication of the BS EN 17412-1:2020 Building Information Modelling - Level of Information Need, these problems have been resolved.
What is Level of Information Need?
Level of Information Need is not really anything new, we are all used to asking for things - whether physical objects such as materials and equipment or virtual objects such as digital data and 3D models. However as an industry we aren’t always good at accurately asking for what we want and so can be surprised at what we get.
The Level Of Information Need standard requires all parties to think more about not just what they want but also why, when, who and how, as well. Let's explore this in a bit more detail.
Why - This relates to the purpose of the information you are requesting - why do you need it. Knowing this will support better transparency in the process.
When - is there a specific date or time the information is needed? Is it needed once or at regular intervals?
Who - who is this information to be shared with? In the standard these people or organisations are described as Actors.
What - What does the information you are requesting relate to - what object, part, assembly, etc. is the request relating to?
Next we need to look at the How part - which is where the level of detail may need to be described quite explicitly. But asking for information accurately will mean you get what you need, without errors or surprises.Â
BS EN 17412-1:2020 divides the How into three specific types of information before asking further, more specific questions, that the person or organisation requesting information need to consider.
1. Geometrical information
How detailed does the information need? Is it conceptual information suitable for Stage 2 of the Digital Plan of Works, Technical Design information to suit Stage 4 or Manufacturing information for Stage 5?
Does the information need to be represented as 0D - a point, 1D - a line, 2D - a flat shape or 3D a volume?
How is the location of the data to be defined - should it be fixed to absolute (Global) or relative (Site) coordinates?
What should the appearance of the information be like - from symbolic to photo realistic?
Does the information need to include any parametric qualities - so the data has its own intelligence?
2. Alphanumerical information
How is the information to be uniquely identified?
What is the correct amount of information content required? This is the metadata associated with the geographical information.
3. Documentation
What additional documentation is required to support the information requested?
This list can look quite daunting but in many cases not everything will be required, while in other cases Tekla software can automatically generate the information that you need to share as part of the IFC export from the model.Â
How to deliver Level of Information Need
In order to accurately define the Level of Information Need every project should include a Building Information Modelling (BIM) Execution Plan. The BIM Execution Plan tells participants (the Actors) what information is going and should ensure that information requirements align with those of BS EN 17412-1:2020.
Level of Information Need is a key aspect in the overall planning of the digital delivery of information to stakeholders on a project or within an organisation. When the right information is requested for the right time to enable the right decisions to be made the construction process becomes less risky and much more productive.
