stop construction and costs are easier to control. This can reduce or eliminate litigation due to cost and schedule overruns. Under this new approach, contributors cannot work in silos. Instead, all parties are collaborating as the model is developed and working together to eliminate clashes. Solving coordination issues virtually in the design phase is much more efficient and cost effective. It also improves safety and reduces labor on the job site. With all stakeholders involved from the outset, knowledge increases through each phase of a project; there is minimal loss of knowledge between phases.
BIM Terminology Among the more common terms you’ll hear associated with BIM are level of development, level of detail and what’s known as the ‘Ds’ of BIM. Level of detail and level of development are often confused, but there’s an important difference between the two. The level of detail refers to the detail put into the model elements/parts, also known as content; it is an input. Take a valve for example. At a higher level of detail, you might see symbols or numbers on a gauge, while at a lower level you might simply see a circular-shaped object denoting a gauge (see figure 2). Both valves are serving the same purpose, taking up the same amount of space, there’s just more detail shown in one versus the other. Level of development, or LOD, is how much the element’s geometry can be relied Figure 2: Level of detail is shown in these two valves. The valve on the left has less detail, but upon by users for processes such as energy takes up the same amount of space as the more detailed valve on the right. analysis, clash detection, exporting reports, producing accurate bills of material (BOMs), and tracking submittals for maintenance. LOD is an output. Level of development, which can vary at different stages of design and construction, ranges from 100 to 500, with 500 being the most developed. Each level defines what the model can reliably be used for. Level 200 includes generic content that serves as a placeholder. A fitting, for example, wouldn’t have proper dimensions, there would be no flow coefficients and it couldn’t be used to extract a bill of material (see figure 3).
Figure 3: LOD 200 on the left; LOD 400 on the right. Notice that modeling the actual fittings to be used required slight alterations to the pipe routing.
Southeast Asia Building JAN-FEB 2017
Southeast Asia Building : Jan-Feb 2017