Last edited 21 Apr 2021

Level of Development LOD


[edit] Introduction

Level of Development (LOD) enables practitioners in the architecture, engineering and construction (AEC) sector to clearly describe Building Information Models (BIMs) throughout the design and construction process.

[edit] The Origin of LOD

The LOD framework was formally established by the American Institute of Architects (AIA) in 2008. Further development has been undertaken by the Associated General Contractors of America (AGC).

However, LOD existed prior to the AIA’s formalised introduction. An early variation of the concept was present in construction analysis software that linked digital models to project costs. Introduced by Vico Software (now part of Trimble), a Model Progression Specification (MPS) was created in order to coordinate consistent BIM model data and associated information.

[edit] LOD or LOd?

In this early instance, LOD was defined as Level of Detail. However, the acronym LOD (in all upper case letters) has since become associated with Level of Development (in the USA - see level of detail for more information about the UK) while LOd is an indication of the original term, Level of Detail.

In the AIA's G202-2013 Building Information Modelling Protocol Form, LOD refers to the Level of Development required for model element content. LOD is the degree to which the componentsspecification, geometry, and attached information have been thought through – or the degree to which project team members can depend on the information when using the model.

On the other hand, LOd is associated with the proportion of detail enclosed within the model element. In other words, a visually detailed element might in fact be generic, and despite its appearance, it might be at a low level of design development.

In the article, “The LOD on the LOD”, Jim Reis, Managing Director of SysQue and Building Data at Trimble notes that LOD (meaning Level of Development) is the most commonly used reference. He adds that as the element or model becomes more developed (LOD), more detail (LOd) subsequently becomes available.

Reis explains that LOD is the depth of thinking applied to the model; thus, it is associated with the reliability of the model. Example: Whether the pipes in a model have been engineered and the permanence of their placement. By contrast, Reis says LOd is associated with the way a model looks. The level of detail refers to the input of the model. Example: Specific shapes and measurable location of steel pipes in a model.

[edit] Six stages of LOD

Ranging from LOD 100 to LOD 500, the LOD framework defines the extent of design detailing in the BIM model for each component.

The six LOD stages are:

The BIM forum has contributed to interpreting the six levels of this framework for building product manufacturers and fabricators in particular - including plumbing, electrical, foundation, roofing, etc. The purpose of this is to foster better collaboration during the design and construction process.

[edit] Related articles on Designing Buildings Wiki

[edit] External resources

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