Level of Definition (LOD) is about managing the risk

LOD is a key aspect in the planning of information delivery to stakeholders.

There is greater value in a model where the accuracy of the geometry and the amount of data has been assured to a recognised standard. This creates greater trust between all the parties working on a scheme.

The more reliable the digital information becomes, the more this information will be re-used not recreated, so saving time and money while increasing accuracy. The right information is passed to the right people at the right time in the right format making the decision making processes much quicker. When design and construction decisions are based upon quality information the construction process becomes more productive and risk-free.

Incomplete information in the process leads to miscommunications, assumptions and rework that adds costs and delays to projects.


Additional Material

Why should my structural BIM software deliver LOD 350/400 out of the box?
Why Delivering LOD The Right Way Brings Success to Clients and Contractors?

Building Information Modelling (BIM) is a collaborative way of working underpinned by digital technologies. These technologies allow for more efficient methods of designing, delivering and maintaining physical built assets throughout their entire lifecycle.

Three things to be in place:

Level of Definition. The amount of information, graphical and non-graphical, that increases over the lifecycle of an asset.

LOD rises over the design and construction phases of a projects. For structural items this information can level out during the operational phase, but in all cases it needs to be aligned to a project milestone.

How the information is described; by using standard classification systems the information created can be shared accurately. In the UK the most common classification systems are Uniclass.

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In the UK LOD is the acronym used for the term Level of Definition. This term is found in PAS 1192-2.

See http://bim-level2.org/en/standards/

In principle this requires employers to define what information they require from their supply chain at what time and in what format. These requirements are set out in a document called the EIRs – Employers Information Requirements – and are linked to the work stages outlined in the seven stages of the Digital Plan of Works. In order to help the UK industry come to an agreement of what is reasonable to provide two reference guides are freely available.

The RIBA Digital Plan of Works – giving high level guidance of what information should be produced at each stage of a project. https://www.architecture.com/knowledge-and-resources/resources-landing-p...

THE NBS BIM Toolkit – an online tool to help project teams define their information requirements in greater detail for a specific project. This also provides a large resource of model objects created for each stage of the Digital Plan of Works to help teams understand the Level of Definition required with their scope of services on a project. https://toolkit.thenbs.com/

LOD requires project teams to collaborate in order to define who is best placed to provide what information at what time on a project. It is linked very closely to lean thinking.

By determining what information is really required at each stage of the project it is likely that the specialist businesses who deliver the scheme on site will be involved earlier in the process so that the team benefits from their expertise rather than making assumptions and creating inaccurate information.

Creating information costs money, creating the wrong information is even more costly with rework, change orders, variations.

In the digital age it can be very easy to create information, but it might not be the right information.

Having a BIM Execution Plan on a project that is aligned to deliver LOD across the lifecycle of the asset means that information is available to the right people to make the right decisions at the right time. And so we have projects delivered on time, on budget and to the required quality – and a satisfied customer who now knows what they are going to get because it is what they defined from the start.