In recent years the construction lifecycle and the lifecycle of buildings has been redefined. The vernacular has moved to include words such as sustainabity and end of life recycling. To construct a building we no longer just visualise the creation of a new building. We are now asked to visulaise the building as a BIM Model with up to 7 dimensions;
- The Design dimension (2D)
- The Specification dimension (utility & amenity)
- The 3D Conceptualised, walk through dimension. (how should the building be put together?)
- The Cost Dimension
- The Time and Construction Dimension (Project Management)
- The As Built Dimension (how was the building really put together?)
- The Lifecycle Management Dimension.(how much will the building cost to run over its projected lifetime, and what will the end of life demolition costs be. This may be used for comparing building options)
Why BIM and CIM?
Do You Want To Exceed All Common Forms Of Construction Efficiency?
BIM & CIM can lead the way in cost and time savings.
Results such as 20% faster construction times in Top End Architectural Homes & 37% Faster Times in Commercial Fit-out have been achieved.
BIM and CIM are not just about sustainability, they are about efficiency and cost
What Is BIM?
Building Information Modeling (BIM)
BIM is the digital representation of physical functional and cost characteristics of a facility. A BIM is a shared knowledge resource for information about a building forming a reliable basis for decisions during its design, preparation, build, and occupation life-cycles. BIM construction models have been succesfully achieved in residential, commercial and industrial construction projects BIM in construction management.
Participants in the building process are constantly challenged to deliver successful projects despite tight budgets, limited manpower, accelerated schedules, and limited or conflicting information. The significant disciplines such as architectural and structural engineering designs should be well coordinated, as two things can’t take place at the same place and time. Building Information Modeling aids in collision detection at the initial stage, identifying the exact location of discrepancies. The BIM format also enables the integration and sharing of data between disciplines. Costs are far easier to control because the shared data between the designer (Architects), the cost engineers (Quantity Surveyors) and the builders (Project Managers) are common and translatable. To complete this integration it is advised that a CIM (Cost Information Model - see below) and project management plan are also completed.
The BIM concept can envisage virtual construction of a facility prior to its actual physical construction, in order to reduce uncertainty, improve safety, work out problems, and simulate and analyse potential impacts. Sub-contractors from every trade can input critical information into the model before beginning construction, with opportunities to pre-fabricate or pre-assemble some systems off-site. Waste can be minimised on-site and products delivered on a just-in-time basis rather than being stock-piled on-site.
Quantities and shared properties of materials can be extracted easily. Scopes of work can be isolated and defined. Systems, assemblies and sequences can be shown in a relative scale with the entire facility or group of facilities. BIM also prevents errors by enabling conflict or ‘clash detection’ whereby the computer model visually highlights to the team where parts of the building (e.g. structural frame and building services pipes or ducts) may wrongly intersect.
What Is CIM?
A lot of focus has been put into the parts of the BIM model that relate to the CAD and drawing aspects of a job. Behind this is the belief that the full benefit of a BIM model lies within the Cost Dimension. And that the effectiveness of the BIM model cannot be gauged without this dimension being active. It can be appreciated that a 3D model can help avoid clashes between contractors, by planning on site delivery through visually staging each part of a job. Losses made due to poor planning are avoidable and a certain partial saving can be made.
But we believe that the significant improvement in construction cost modelling actually occurs between the estimating and the project management disciplines, dimension 4 & 5 of the model. By creating the pricing data in a way that it is used by the Project Managers, the transparency between the disciplines produces a far more effective outcome. We call this the CIM model (Cost Information Model). This key component sits within the BIM model and form the esential hub between the components.
This requires the production of detail and moves away from the use of bulked rates. For example, rather than having a global rate of $18.50/m2 fitted for plasterboard, the Quantity Surveyor calculates the amount of plasterboard with hardware, labour, wastage and rounding up requirements. You cannot order half a unit (sheet) of plasterboard, glue or screws. And the labour time is definable. So if the costing data is groomed for usage by the project management team, a lot of time in organising the program is saved. And all accounting and back-costing functions become synchronous.
Further, if the Quantity Surveyor calculates 200 sheets of plasterboard with 400 man hours to fix the plasterboard, this information should flow through to produce the purchase orders, site deliveries and the Bill of Labour that the Project Manager uses.
The Bill of Labour will help the Project Manager assign the work. If he assigns 4 men to do the fitting, then that becomes 100 work hours in the program on a certain start date with a baseline and float also defined.
By using the costing data on the left side of the curve, to run the construction program on the right side, a significant advantage is attained. International examples are showing 20-30% time savings on some jobs.
Why Aren’t BIM & CIM Used More Often?
BIM and CIM require more upfront planning to achieve. And on larger projects early contractor involvement may incur upfront costs.
The cost of uniting the professionals at the early stages appears to be unecessary. However the benefits of this additional input far exceeds the costs.
BIM and CIM also offer an incredible amount of certainty as to deadline and cost management. In many cases the additional cost savings achieved with BIM management can help enhance the property value and the return on investment.