LOD with BIM

Reduce Owner Costs by Leveraging LOD with BIM


BIM provides many benefits to the building design and engineering by improving collaboration for all parties involved- Architects, Engineers, and the Building Owners. Currently the process is geared toward communicating design intent - information about materials and systems. However, it's important for owners to make the most out of BIM's capabilities early in the project lifecycle. Building Owners need to get the information they need for their facility system Space, Maintenance, management, and budgets down the road. One key way that owners can participate in, and benefit from BIM, is by requesting LOD specifications at the beginning of a project.

What is LOD?

Level of Development (LOD) enables professionals in the AEC Industry to specify with a high level of clarity the content and reliability of model elements at various stages in the design and construction process. The BIMForum has provided an updated 2016 LOD Specification, available here. This defines and illustrates characteristics of model elements of different building systems at different LOD’s. This allows BIM authors to define what their models can be relied on for, and allows downstream users to clearly understand the usability and the limitations of models they are receiving.

The different levels are as follows:

LOD 100 General concept of where physical elements are with a structure
LOD 200 Design development; refine geometry that starts to replace generic blocks with more detailed components
LOD 300 Documentation; Property specifications, such as measurements, are suitable for design intent like cost and bidding
LOD 350 Proper cross-trade coordination definitions, including connections and interfaces between disciplines
LOD 400 Construction; supports detailing, fabrication and installation/ assembly
LOD 500 Facilities Management – suitable geometry and information to support operations and maintenance that should be as-built and field verified
 

 

What does the owner need to know?

Owners should focus their sights on the information provided by LOD 400 – 500. Keep in mind, that LOD’s represent the progressive maturity of an element included in a facility. For instance, let’s focus on an AC unit within a building. An LOD 100 would only specify the general placement of an AC unit in the building. As an owner, you will benefit from having detailed specifications of the AC unit as it comes in – manufacturer information, size specifications, warranty details, to best service the element down the road.

From an owner’s perspective, it’s valuable to identify two types of elements to specify in their LOD request – ‘High-touch service devices’ and ‘Big-ticket items’. High-touch service devices are not necessarily expensive, but represent a volume of elements in a system, like VAV boxes, fluorescent ceiling lights, and sinks, things that are typically in a near-constant run status. Having an LOD 400 in place for these items, that will require regular updates and maintenance, gives an owner information on how to install and update their functional elements.

Big-ticket items include elements that are costly upfront, like elevators, water chillers and AC Plant. An LOD 500 will provide you with all the information you need to know to service these elements down the road, like the maintenance requirements, when the item was first turned on, and the length of the warranty.

How do I request LOD?

Define and ask for your LOD specifications before the start of a project in a construction or bid document to ensure your partners know they are responsible for handing over these digital modelling requirements. It’s important to include these requests upfront. Otherwise, the design and construction team often won’t model greater than LOD 300 because the information provided by levels above 300 are not necessary for them to get their job done. However, as a recognized data specification, LOD is easy to implement and designers or engineers won’t need to create a customized data delivery matrix to provide you with your requested information.

Time & Money Savings from LODs

It’s important to remember that data validation is critical, but best done at key milestones throughout a project’s lifecycle. Keep track of your LOD specifications and throughout the project, evaluate the LODs to see if they convey the necessary information, or are headed in that direction. While LOD expectations may require extra work upfront, time and money can be saved down the road when considering the data value that comes from the digital handover in LOD 400 -500.

 

By AJ Bridwell | July 6th, 2017