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Building Information Modeling (BIM) is a process involving the generation and management of digital representations of physical and functional characteristics of places. Building Information Models (BIMs) are files (often but not always in proprietary formats and containing proprietary data) which can be exchanged or networked to support decision-making about a place. Current BIM software is used by individuals, businesses and government authorities who plan, design, construct, operate and maintain diverse physical infrastructures, from water, wastewater, electricity, gas, refuse and communication utilities to roads, bridges and ports, from houses, apartments, schools and shops to offices, factories, warehouses and prisons, etc.
The concept of BIM has existed since the 1970s. The term Building Information Model first appeared in a 1992 paper by G.A. van Nederveen and F. P. Tolman. However, the terms Building Information Model and Building Information Modeling (including the acronym "BIM") had not been popularly used until Autodesk released the white paper entitled "Building Information Modeling". Jerry Laiserin helped popularize and standardize the term as a common name for the digital representation of the building process as then offered under differing terminology by Graphisoft as "Virtual Building", Bentley Systems as "Integrated Project Models", and by Autodesk or Vectorworks as "Building Information Modeling" to facilitate exchange and interoperability of information in digital format.
The National Building Information Model Standard Project Committee has the following definition:
Traditional building design was largely reliant upon two-dimensional drawings (plans, elevations, sections, etc.). Building information modeling extends this beyond 3D, augmenting the three primary spatial dimensions (width, height and depth) with time as the fourth dimension (4D) and cost as the fifth (5D), etc. BIM therefore covers more than just geometry. It also covers spatial relationships, light analysis, geographic information, and quantities and properties of building components (for example, manufacturers' details).
BIM involves representing a design as combinations of "objects" – vague and undefined, generic or product-specific, solid shapes or void-space oriented (like the shape of a room), that carry their geometry, relations and attributes. BIM design tools allow extraction of different views from a building model for drawing production and other uses. These different views are automatically consistent, being based on a single definition of each object instance. BIM software also defines objects parametrically; that is, the objects are defined as parameters and relations to other objects, so that if a related object is amended, dependent ones will automatically also change. Each model element can carry attributes for selecting and ordering them automatically, providing cost estimates as well as material tracking and ordering.
For the professionals involved in a project, BIM enables a virtual information model to be handed from the design team (architects, surveyors, civil, structural and building services engineers, etc.) to the main contractor and subcontractors and then on to the owner/operator; each professional adds discipline-specific data to the single shared model. This reduces information losses that traditionally occurred when a new team takes 'ownership' of the project, and provides more extensive information to owners of complex structures.
Use of BIM goes beyond the planning and design phase of the project, extending throughout the building life cycle, supporting processes including cost management, construction management, project management and facility operation.
Building information models span the whole concept-to-occupation time-span. To ensure efficient management of information processes throughout this span, a BIM manager (also sometimes defined as a virtual design-to-construction, VDC, project manager – VDCPM) might be appointed. The BIM manager is retained by a design build team on the client's behalf from the pre-design phase onwards to develop and to track the object-oriented BIM against predicted and measured performance objectives, supporting multi-disciplinary building information models that drive analysis, schedules, take-off and logistics. Companies are also now considering developing BIMs in various levels of detail, since depending on the application of BIM, more or less detail is needed, and there is varying modeling effort associated with generating building information models at different levels of detail.
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, structural and MEP 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 concept envisages virtual construction of a facility prior to its actual physical construction, in order to reduce uncertainty, improve safety, work out problems, and simulate and analyze 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.
BIM can bridge the information loss associated with handing a project from design team, to construction team and to building owner/operator, by allowing each group to add to and reference back to all information they acquire during their period of contribution to the BIM model. This can yield benefits to the facility owner or operator.
For example, a building owner may find evidence of a leak in his building. Rather than exploring the physical building, he may turn to the model and see that a water valve is located in the suspect location. He could also have in the model the specific valve size, manufacturer, part number, and any other information ever researched in the past, pending adequate computing power. Such problems were initially addressed by Leite and Akinci when developing a vulnerability representation of facility contents and threats for supporting the identification of vulnerabilities in building emergencies.
Dynamic information about the building, such as sensor measurements and control signals from the building systems, can also be incorporated within BIM to support analysis of building operation and maintenance.
Due to the complexity of gathering all the relevant information when working with BIM on a building project some companies have developed software designed specifically to work in a BIM framework. These packages (eg: Autodesk Revit) differ from architectural drafting tools such as AutoCAD and VectorWorks by allowing the addition of further information (time, cost, manufacturers' details, sustainability and maintenance information, etc) to the building model.
BIM is often associated with Industry Foundation Classes (IFCs) and aecXML – data structures for representing information. IFCs have been developed by buildingSMART (the former International Alliance for Interoperability), as a neutral, non-proprietary or open standard for sharing BIM data among different software applications (some proprietary data structures have been developed by CAD vendors incorporating BIM into their software).
Poor software interoperability has long been regarded as an obstacle to industry efficiency in general and to BIM adoption in particular. In August 2004 the US National Institute of Standards and Technology (NIST) issued a report which conservatively estimated that $15.8 billion was lost annually by the U.S. capital facilities industry due to inadequate interoperability arising from "the highly fragmented nature of the industry, the industry’s continued paperbased business practices, a lack of standardization, and inconsistent technology adoption among stakeholders".
An early example of a nationally approved BIM standard is the AISC (American Institute of Steel Construction)-approved CIS/2 standard, a non-proprietary standard with its roots in the UK.
There have been attempts at creating a BIM for older, pre-existing facilities. They generally reference key metrics such as the Facility Condition Index (FCI). The validity of these models will need to be monitored over time, because trying to model a building constructed in, say 1927, requires numerous assumptions about design standards, building codes, construction methods, materials, etc., and therefore is far more complex than building a BIM at time of initial design.
BIM usage in Hong Kong has grown rapidly since 2005. Then a small group of professionals (including Francis Leung, David Fung and YY Yip) embraced BIM in their work, and an Autodesk Industry Advisory Board (AIAB) was initiated by Autodesk to maintain the momentum, and it is increasingly widely used. The Hong Kong Institute of Building Information Modelling (HKIBIM) was established in 2009. The Hong Kong Housing Authority set a target of full BIM implementation in 2014/2015. BuildingSmart Hong Kong was inaugurated in Hong Kong SAR in late April 2013.
In India BIM is also known as VDC: virtual design and construction. India is an emerging market with an expanding construction market and huge potential for large scale residential and commercial development (because of population and economic growth). It has many qualified, trained and experienced BIM professionals who are implementing this technology in Indian construction projects and also assisting teams in the USA, Australia, UK, Middle East, Singapore and North Africa to design and deliver construction projects using BIM.
The Iran Building Information Modeling Association (IBIMA) shares knowledge resources to support construction engineering management decision-making. It was founded in 2012 by professional engineers from five universities in Iran, including the Civil and Environmental Engineering Department at Amirkabir University of Technology.
The Building and Construction Authority (BCA) has announced that BIM would be introduced for architectural submission (by 2013), structural and M&E submissions (by 2014) and eventually for plan submissions of all projects with gross floor area of more than 5,000 square metres by 2015.
Small BIM-related seminars and independent BIM effort existed in South Korea even in the 1990s. However, it was not until late 2000s that the Korean industry paid attention to BIM. The first industry-level BIM conference was held in April, 2008, after which, BIM has been spread very rapidly. Since 2010, the Korean government has been gradually increasing the scope of BIM-mandated projects. McGraw Hill published a detailed report in 2012 on the status of BIM adoption and implementation in South Korea.
In a number of European countries, several bodies are pushing for a more integrated adoption of BIM standards, in order to improve software interoperability and cooperation among actors of the building industry.
In France, examples include the FFB (Fédération Française du Bâtiment), and the French arm of buildingSMART.
In Norway BIM has been used increasingly since 2000. Several large public clients require use of BIM in open formats (IFC) in most or all of their projects. The Government Building Authority bases its processes on BIM in open formats to increase process speed and quality, and all large and several small and medium-sized contractors use BIM. National BIM development is centred around the local organisation, buildingSMART Norway which represents 25% of the Norwegian construction industry.
In Switzerland, ETH Zurich university has taught CAD and digital architecture since 1992 through Prof. Dr. Schmitt. During 2013, BIM awareness among a broader community of engineers and architects was raised due to the open competition for Basel's Felix Platter Hospital where a BIM coordinator was sought. BIM has also been a subject of events by the Swiss Society for Engineers and Architects, SIA.
On 1 November 2011, the Rijksgebouwendienst, the agency within the Dutch Ministry of Housing, Spatial Planning and the Environment that manages government buildings, introduced the RGD BIMnorm, which it updated on 1 July 2012.
In the UK, the Construction Project Information Committee (CPIC), responsible for providing best practice guidance on construction production information and formed by representatives of major UK industry institutions, has produced a similar definition to that produced by the US National BIM Standard Project Committee. This was proposed to ensure an agreed starting point, as different interpretations of the term were hampering adoption.
In May 2011 UK Government Chief Construction Adviser Paul Morrell called for BIM adoption on UK government construction projects of £5million and over. Morrell also told construction professionals to adopt BIM or be "Betamaxed out". In June 2011 the UK government published its BIM strategy, announcing its intention to require collaborative 3D BIM (with all project and asset information, documentation and data being electronic) on its projects by 2016. Initially, compliance will require building data to be delivered in a vendor-neutral 'COBie' format, thus overcoming the limited interoperability of BIM software suites available on the market. The UK Government BIM Task Group website gives a clear message to the whole supply chain about the government's BIM programme and requirements.
National Building Specification (NBS), owned by the Royal Institute of British Architects (RIBA), publishes research into BIM adoption in the UK. There have now been three annual surveys. The March 2013 survey of 1,350 UK construction professionals revealed that BIM adoption among UK construction professionals had increased from 13% in 2011 to 39% in 2013.
Several UK-based websites host BIM objects, including those of many construction product manufacturers. In March 2012, NBS launched the National BIM Library, featuring a range of generic and proprietary construction elements suitable for BIM.
Founded in December 2008, the Canada BIM Council is a consensus- and committee-driven organization for BIM in Canada developed by business leaders to standardize the use of models in architecture, engineering and construction.
The Associated General Contractors of America and U.S. contracting firms have developed various working definitions of BIM that describe it generally as:
Although the concept of BIM and relevant processes are being explored by contractors, architects and developers alike, the term itself has been questioned and debated with alternatives including Virtual Building Environment (VBE) and virtual design and construction (VDC) also considered.
BIM is seen to be closely related to Integrated Project Delivery (IPD) where the primary motive is to bring the teams together early on in the project. A full implementation of BIM also requires the project teams to collaborate from the inception stage and formulate model sharing and ownership contract documents.
The American Institute of Architects has defined BIM as "a model-based technology linked with a database of project information", and this reflects the general reliance on database technology as the foundation. In the future, structured text documents such as specifications may be able to be searched and linked to regional, national, and international standards.
BIM is a relatively new technology in an industry typically slow to adopt change. Yet many early adopters are confident that BIM will grow to play an even more crucial role in building documentation.
Proponents claim that BIM offers:
Green Building XML (gbXML) is an emerging schema, a subset of the Building Information Modeling efforts, focused on green building design and operation. gbXML is used as input in several energy simulation engines. But with the development of modern computer technology, a large number of building energy simulation tools are available on the market. When choosing which simulation tool to use in a project, the user must consider the tool's accuracy and reliability, considering the building information they have at hand, which will serve as input for the tool. Yezioro, Dong and Leite developed an artificial intelligence approach towards assessing building performance simulation results and found that more detailed simulation tools have the best simulation performance in terms of heating and cooling electricity consumption within 3% of mean absolute error.
Explorations are underway to pair computer network users' personal, private and public authentication choices, geographic mapping systems and evolving cloud computing security architecture models, together, to offer customers of geospatial securitization services intuitive new ways to organize their personal, private and public applications and storage. For individuals, businesses and government authorities who generate and manage building information, new ways to discover, share and work on data, within the context of particular places on earth, will be offered. David Plager, AIA, conjectures that today's web will give way to tomorrow's geo-web where data will be structured first by place (eg a postal address) and then by space (Personal (one user), Private (a group of users) and Public (all users)).