BIM points way to efficiency
TAHIR SHARIF, president of buildingSmart ME, elaborates on the building information modelling (BIM) process and the crucial role it plays in reducing costs
01 February 2010
The construction industry is rife with problems such as delays, rework, standing time, material waste, poor communication, conflict and being over budget, compounded by the global slowdown and the need to address sustainability issues.
The challenge we all face is to encourage continued investment in tackling these issues in a market made ‘nervous’ by a reduction in the value of property and subsequent threat to profits. A way to restore investor confidence is through reducing investment risk by producing more at a lower cost, which can be achieved by eliminating waste and improving overall productivity across the construction process.
Addressing waste – cost, time and materials – is a big part of any solution, which should effectively integrate design, construction and facilities management (whole of life costs). In addition, new legislation for eco-friendly construction has to be incorporated into the construction process.
It is now a decade since the publication of ‘Rethinking Construction’, the eminent report by Sir John Egan, which highlighted the amount of waste in construction. It quoted the results of recent studies in the US, Scandinavia and the UK, which suggested that up to 30 per cent of construction is rework; labour is used at only 40 to 60 per cent of potential efficiency; and at least 10 per cent of materials are wasted.
The message is clear: there is plenty of scope for improving efficiency and quality, simply by taking waste out of construction and one of the key drivers identified by the report is integrated processes and teams.
The BIM process
The BIM (building information modelling) process and technologies have been developed specifically with these problems in mind and have been very successful in resolving them.
BIM is a business process supported by technology, which itself is optimised by deploying the process. While traditional methods use technology in isolation, the BIM process uses technology in collaboration.
In this environment, all stakeholders in the construction process including owner/developer, project managers, consultants, contractors, subcontractors and facilities management, have access to the same design, cost and scheduling information at the same time. It requires a different business and thought process as disciplines are brought together earlier to share information and work practices.
At the heart of the BIM process is the 3D building information model created by advanced software tools. Unlike the simple lines and curves associated with traditional 2D CAD systems, BIM software technology introduces intelligence into the design. As well as being described by dimensions and locations, objects also have data attached relating to materials and compositions. In simple terms, in a building information model, every object knows what it is, where it is, how big it is and what it is made of.
The key elements of design, that is, architectural, structural and MEPF (mechanical/electrical/plumbing/fire protection), are integrated into a single building information model, enabling all design data to be assembled in one space rather than via the hundreds or thousands of drawings associated with the traditional process.
Reducing costs
The first benefit achieved is reducing costs through the business process by:
• Rapid exchange of design information, as easy ‘what if’ scenarios allow more design iterations and a more efficient decision-making process;
• Time is saved in documenting decisions;
• Drawings produced directly from the model rather than creating them individually;
• Data required for calculation of structural integrity is produced from the model, thus saving time in producing engineering calculations;
• All geometric and spatial data required to perform energy calculations are produced directly from the model and time is saved in demonstrating environmental compliance and optimising lifecyle costs;
• Accurate BOQs (bills of quantity) are produced directly from the model through integration of cost and scheduling into the single environment;
• Data required to control procurement is contained in the completed construction model, thus saving time and optimising the efficiency of the procurement process; and
• The ‘as built’ model contains the data required to inform facilities management (FM), thus integrating it into the single environment.
The second benefit is reducing costs by eliminating waste through:
• Design validation, as early analysis of designs in the 3D environment identifies minor and major errors, thus removing the risk and reduction of rework;
• Integrating MEPF designs with the structure and architecture helps identify and eliminate co-ordination problems, thereby removing the risk, reducing rework and standing time and minimising material waste;
• Construction in a ‘virtual’ environment produces accurate shopdrawings – off-site manufactured items ‘fit’ reducing rework, material waste and standing time;
• Improved monitoring of site logistics and project progress, which reduces time and material waste through more accurate site/project management;
• Optimised quantity-driven cost plans help reduce waste through accurate procurement;
• Optimised quantity-driven construction schedules reduce standing time and enable on time/early completion of projects; and
• Reduced errors and rework effectively reduces conflict and claims.
The third benefit is gained through improving quality by:
• Early identification and elimination of risk/error through design validation and co-ordination, hence higher quality and ‘fit for purpose’ construction;
• Reduced FM and energy costs, and greater environmental compliance;
• Visual information in a single 3D environment results in more efficient communication at all project levels, increasing understanding and facilitating decision-making;
• Detailed design information in a single environment ensures more efficient communication of requirements to subcontractors and trades, thus improving efficiency and quality of execution;
• Integrated cost/time/procurement results in more efficient communication and easier project management/supervision; and
• On-site logistics and progress is monitored in a single environment, ensuring accurate information transfer for quantity surveyors (QSs) and project managers (PMs).
