Sustainable development requires that new technology is used to drive the management, distribution, optimization, and consumption of resources. New technology mostly means software. The cleanest and leanest systems and facilities in the world are designed and managed with software. From the perspective of construction, BIM (Building Information Modeling) software can be used to optimize and economize the selection and use of materials and resources in a construction process.
Sustainability means meeting the needs of today without compromising the ability of future generations to meet their needs. Most of the advances promoted by the sustainability mega-trend are derived from something very intangible, software. Software is a sustainable product, especially when it comes to supporting other sustainable tools to do more with less.
The sustainability of the construction business can be measured by defining how ‘green’ the building is in terms of energy and material consumption during its construction, usage, maintenance, and demolition. There is no need to invent that much new; a lot can be learned from established practices used in, for example, electricity distribution and the maintenance processes of off-shore structures. Software can be used to optimize material selection, utilize the resources of the construction process more efficiently, and improve the maintenance of buildings by a diversity of applications.
Up to 40% of all solid waste comes from construction
The construction process currently generates significant quantities of waste: about a fifth of all waste and up to 40% of all solid waste is attributable to the construction sector. As much as 10% to 30% of construction material is wasted during construction. The formwork for cast-in-place concrete is one of the biggest sources of construction waste. Working on a temporary site, it is often difficult to arrange recycling logistics, and many subcontractors think it is better to deliver too much than too little. Moreover, mistakes in design can cause unnecessary demolishing and rebuilding.
Delays in construction are considered expensive whereas material is seen as cheap – but is it cheap from the environmental point of view? The question is how to transfer the huge amount of relevant information created during the design and construction in a usable form onwards and how to manage that information efficiently and communicatively. Drawings, tables, databases, schedules and other necessary items are supported by specific applications, the selection of which depends heavily on the buildings to be managed.
The green advantage of modeling
BIM as a process is mostly promoted to the construction industry by explaining how it is possible to build more, build more quickly, and save or make money when doing so. However, working more efficiently does not just have to be about saving or making money. Many successful projects boast an environmental dimension adding to the financial and time benefits. There is a definite green advantage to exact 3D modeling, detailing, and just-on-time delivery: minimizing the use and waste of material, power and transportation, as well as environmentally costly reworking and documentation. It only makes sense to try and reduce one of the most used materials in construction: paper. Using BIM software instead of fragmented documents and tons of drawings allows more precise, efficient and environmentally friendly communications and control for all involved in using and maintaining the building
When properly implemented, building information models can help optimize the use of resources and prevent costly and environment-loading mistakes in many critical phases of the design and construction process. BIM makes it possible to consider alternative designs and evaluate their environmental costs. An error-free process can be achieved by using automatic data transfer instead of manual printout and key-in actions. Another area where accurate modeling creates a huge potential for benefits is interoperability between the construction disciplines: identifying possible problems early during the design and preventing cross-discipline mistakes.
How can BIM help save the environment?
So far BIM has been very much a tool for architects, emphasizing the early part of a building’s life cycle. In the current changing scenario, the models can be used to maximize energy efficiency, optimize material selection, and of course to get the most out of the area and space available. Construction companies have been using numerous 3D tools for a long time but in isolation. True BIM as a process that supports integrated project delivery (IPD) is still in its infancy. It is not about availability of technology but rather the industry’s resistance to change.
An intelligent BIM tool includes libraries of components defined and accepted for use in the industry and is thus ‘forcing’ standardization, also by supporting standardized data exchange formats or methods, such as IFC (Industry Foundation Classes), IBS (Industrialized Building System) and COBIE (Construction-Operations Building Information Exchange). A model created with such a tool can communicate directly with procurement: accurate material lists including scheduling can be derived from the model to financial and material management systems directly. An intelligent model also communicates with machinery, integrating design to production without another error-prone key-in procedure, and enables the transfer of a big part of the construction work from the always temporary construction site to off-site factories. With the help of BIM, much construction is being moved off site, prefabricated parts are brought on site with fewer errors, and all this makes the construction process leaner, with less wasted time, labor effort and materials, and better possibilities for controlled recycling of extra materials in the factory.
Getting there
Spearhead projects have achieved significant savings in both costs and the environmental aspect by using lean BIM-based processes. The Sydney Opera House project used standardized BIM systems as integrated information sources, proving that an IFC-compatible model is extensible to incorporate organisation-specific requirements. It can be used by a variety of different software systems, including facilities management systems. Other related software, such as energy prediction models and on-site monitoring, are also available using IFC data.
A great example of savings on environmentally friendly materials and construction practices by BIM is the Meadowlands Stadium in New Jersey, in which the 4D construction model was used to manage workflow integrated with RFID technology to tag and track building materials. Important information about the materials was captured from several vendors’ systems and merged in the 3D structural model in real-time. As a result, the project owner managed to optimize and integrate the complex supply and delivery chain as a whole, saving a million dollars in the use of material and labor resources. “Bringing together RFID, BIM and field software together into a single solution has vastly improved our ability to track materials along the entire process, from the plant to erection in the structure,” said David Campbell, vice president for Skanska USA.
The Adamstown project has been planned as a sustainable community, its buildings designed to achieve in excess of 40% energy savings using 30% renewable energy sources. It has been estimated that through the use of low-carbon concrete, the community will save 7,300 tons of CO2. The project has shown that BIM can benefit both the design and manufacturing process. The manufacturer’s components for precast construction that lower energy consumption by allowing minimal air infiltration and enable internal temperature changes to reduce peak heating and cooling loads were integrated in the BIM. Richard Kowalski, the chief engineer for O’Reilly Concrete, asserts that 3D modeling was essential when designing such complex concrete structures. “The possibility to transform 3D model onto the set of production and construction drawings enabled detailers to assess critical points in the structure and in the design connections, facilitating fewer mistakes in the production.”
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