The Virtual Building Print
Wednesday, 12 September 2007 03:16

The Virtual Model or BIM has definitely its advantages against the typical CAD as practiced today. Why Architects should be looking at adopting these new technologies and how Contractors could benefit from their use.

[[Building Information Model]] or BIM is a 3D approach to CAD that uses, as building blocks, virtual objects that emulate the real life construction components. Rather than using vector elements such as lines and shapes to draft the drawings of the project, the designer builds his project on the computer using virtual objects such as walls, floors beams, columns, doors, windows, fixtures etc. More and more people in the construction industry are looking at adopting the BIM. A recent survey showed the majority of the Architects in North America think that BIM will eventually overtake traditional CAD as the as the standard computer tool. Some developers and real-estate owners are pushing for the adoption of the BIM, when they understood how efficient the integration of building Management Systems into the Virtual Model could be in helping them manage their properties.

Traditional CAD, whether it is 2-D drafting or 3-D modeling, has been around for a while now. It has enabled the Designers to produce cleaner drawings and elaborate photorealistic models of their projects. It failed however to improve on their workflow. Traditional CAD has translated the manual drafting to the computer. The process of Design is far from being a linear one. Disruptions due to the complexities of construction design, like Site restrictions, client’s interventions, cost, technical hurdles, building laws and other considerations bring the designer on numerous instances back to the drawing board (or CAD workstation). The problem of the 2-D drafting process is the fact that once the design change, all the drawings need to be updated. The process is time consuming and prone to errors. Coordination issues arise between the plans, the schedules, the quantities, and the different disciplines. More resources have to be allocated to double check plans. Sometimes some issues are only discovered on site. These errors and the delays they are causing increase the cost of construction worldwide by billions of dollars every year.

The BIM allocates a [[Database]] to the Model. The virtual building components contain information about their dimensions, levels, composition, material, thermal properties etc. As a result the BIM will predict the way those objects can behave and interact with each other. The Designer’s work changes from drawing plans, section and elevations and then extracting the 3-D model to constructing a Smart model of the building that generates the 2-D drawings, 3-D perspectives and animations as well as other vital information such as Schedules, Quantities, Estimates, [[Solar gain]], Energy Dissipation, Building Assemblies etc.

The adoption of the BIM by the Architectural Practices will bring them undeniable advantages. By uniting the 2-D and 3-D in one single Model, the BIM allows a better grasp of the whole project. The Architect will therefore gain more control and enhance his creativity. The focus of the Architect shifts from coordinating the drawings to improving the design and solving design problem. Implementing design alternatives become a much easier task. The work process becomes much smoother since one rectification on the model applies to all generated drawings and schedules. It enhances the interaction with the customer. BIM makes the changes implemented to the Design faster. The customer gets their feedback faster. Items like Cost Estimate, Solar Studies etc. stay updated through the changes. Collaboration and coordination become much easier. Once all the factors are keyed in, designing in BIM is faster than the traditional CAD.

The advantages of adopting the BIM go beyond the Architectural Practice and the Design stage. It extends to the other stages of the buildings lifecycle.

The advantages for the Constructors of having the building constructed in the computer before being built on site are undeniable. The BIM can communicate with the Project Management Software, which adds 2 new dimensions to the 3-D model: Time and Budget. This helps them with construction cost modeling and construction phase scheduling. Contractors and Project Managers are considering the adoption of the BIM to save them time and money.

Building owners can also take advantage of the new technologies. Facility Management is greatly enhanced by the BIM. All the As-built elements are present within the model and can relate to a database that can detail any maintenance done on these elements, dates, people involved, etc.

At a certain point BIM will become essential to Architects. How to transition to BIM from traditional CAD is presently uncertain. Architects are afraid that it will disrupt the workflow and they will have a hard time adjusting from the true-and-tested traditional CAD. The advice we give the Architects looking into such a transition is to take it progressively. Start one project on BIM. A big misconception about the BIM is thinking that it is a total departure from 2-D CAD. The BIM can easily import and integrate 2-D plans (to be used as references) and 2-D construction details. Detail libraries will stay very useful.

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Last Updated on Tuesday, 18 November 2008 01:49