Application Feature ARCHITECTURE
At level 400, that same element would identify the fitting manufacturer and model, it would take up the correct amount of space in the model and include details that could be used for energy analysis. Level 400 is a construction-level model that can be used for fabrication. As for the ‘Ds’ of BIM, when engineers and contractors refer to 3D or 5D, for example, they’re referring to the ‘dimensions’ of BIM, including the model itself and what can be done with it. The number of dimensions has evolved over the years, with 3D through 7D most often recognised today. 3D is the actual 3D building model and its components, including safety and logistics models, animations and walk-throughs. In the case of a renovation, an existing conditions model can be derived from field measurements or laser scanning. 4D refers to scheduling. A construction schedule can be created with the model, and project phasing simulations can help plan what will be installed when, as well as the sequence in which things will be installed. In addition to identifying physical clashes during coordination, software can be used to determine which trades are going to clash during installation to avoid delays on the job site. 4D also includes lean scheduling of procurement, which enables just-in-time deliveries to the job site or fabrication shop. Contractors can essentially back-time construction and create a fabrication schedule and delivery plan to ensure equipment and materials arrive on the jobsite in the proper area of the building, bagged and tagged just in time for a labor-saving installation. 5D is estimating. At higher levels of development with intelligent content, the model can be used for real-time cost planning. Quantities can be extracted and detailed cost estimates created. 5D also enables value engineering and trade verification. Value engineering analyses possible outcomes to determine the most efficient and cost-saving option. Think of it as ‘what-if scenarios.’ For example, what if we evaluate efficiency and energy costs on two chiller plant designs, one using two large chillers and one using three smaller chillers with variable speed pumps? Initial installation costs and operating costs can be compared to select the most efficient design for the owner. Trade verification allows the general contractor and owner to use the model to verify estimates and costs for all subcontractors. 6D is sustainability. A conceptual energy analysis can be conducted early in the design phase, while detailed energy tests can be performed later in the design process. This can help reveal energy-saving alterations, for example, changing the angle of the building or the glass type to reduce cooling costs based on how the sun hits the building. If the project is aiming for LEED certification, sustainable elements can be tracked. 7D refers to facility management, in other words, use of the model for operation and maintenance of the building. The owner can be provided an intelligent 3D model file with embedded equipment and product submittals for quick reference when maintenance is required. Through the Construction Operations Building Information Exchange (COBie), facility managers receive building data, not geometric modeling data, that allows them to track assets and warranties and develop preventative maintenance plans. This eases the traditional handover of paper construction documents that facility managers must then manually enter into a computerised maintenance management system (CMMS). It is important to note that, although the dimension numbers rise sequentially, they shouldn’t be considered stages of a project. Elements of 6D can be done at any point in a project; some of these procedures might be performed before the estimating tasks of 5D. 4D scheduling might occur hundreds of times throughout a project.
Benefits of BIM BIM delivers numerous benefits to all stakeholders throughout the project lifecycle. Early collaboration and virtual coordination reduces rework and change orders that slow construction and increase costs. By simplifying material management and pre-planned deliveries, BIM helps contractors reduce jobsite hours, which can improve safety ratings. Ultimately, the early coordination and collaboration can compress the construction schedule, reduce overall construction costs and reduce or eliminate litigation. BIM takes quite a bit of time, a lot of resources and even some sacrifice from a financial point of view. Contractors looking to add BIM capabilities will have to entertain reviewing and adjusting workflows and processes and potentially acquiring new computer hardware and software. There will be a lot of training required, and several new hires may need to be brought in. However, contractors that are able to meet BIM requirements are more competitive; they can win more projects and, in due course, make more money.
About the Author Jeff Leighton is the Senior Project Coordinator within the Construction Piping Services department at Victaulic, a manufacturer of mechanical pipe joining and fire protection systems. Jeff is a member of the Associated General Contractors of America (AGC) and the NBIMS-BIM Standard Subcommittee. He holds an AGC Certificate of Management-Building Information Modeling (CM-BIM). For more information, visit www.victaulic.com.
JAN-FEB 2017 Southeast Asia Building
Southeast Asia Building : Jan-Feb 2017