WHAT IS BIM
WHAT IS BIM……………………………………………………
A BRIEF HISTORY OF BIM……………………………………………..
BIM is a single data storage accessible and shared by all the stakeholders……………
Bidirectional processes: Automatic Feedback………………………………
Parameterized objects in the model…………………………………….
Visualization versus Representation…………………………………….
Efficiency of the simulation through all the life cycle of the project…………………
USES AND IMPLEMENTATION AREAS……………………………………..
5D: Estimating and cost control……………………………………….
6D: Sustainability and energy efficiency………………………………….
7D: Facility management and maintenance……………………………….
Reduce risk of error and rework……………………………………….
Optimization through all the project life cycle………………………………
Need of Standards and Regulations…………………………………….
Need of Skilled Personnel……………………………………………
Operational or Implementation Issues…………………………………..
WORK METHODOLOGY AND ORGANIZATION………………………………..
BIM IMPLEMENTATION VALORATION…………………………………….
BIM EXECUTION PLAN
The following master’s degree project consists of the acquirement of a basic knowledge of Building Information Modeling (BIM) concept and software tools. BIM is a concept that is becoming more and more common in the architectural, engineering and construction (AEC) industry worldwide. The student will make the necessary research in order to be able to understand what is BIM, which is the current situation of this new concept in the AEC industry, which are the main areas of implementation of BIM in the AEC industry and which benefits and challenges does it presents. During the information research process is done, the student will familiarize wit one of the most extended used software for Building Information Modeling, Revit.
The student will collaborate in the development of a Revit model of the Water Resources Engineering Laboratory of the Engineering Hall Building of the University of Wisconsin-Madison. Within the collaboration in the Revit model and also the use of other support software such as Naviswoks, the student will improve her software skills facing the potential challenges that the model could present.
Finally, the student will combine these two theoretical and practical parts of the project analyzing which characteristics of BIM have been implemented in the Revit model and which others could have been implemented but have not.
Moreover, although it will not be implemented for the development of the Revit model, the student will develop a BIM Execution Plan that could have been implemented.
The paper will be organized in two main parts. The first one, “What is BIM?” will contain all the information related to BIM that will give the reader an understanding of the importance of this new concept and its situation in the AEC industry. The second part, “Case study” will describe the laboratory modeling process and the relationship between the procedure followed and BIM characteristics. Finally it will be done a overall conclusion about the project itself and BIM in the AEC industry.
The first part of the project will need to give a clear and understandable answer to the following questions:
- What is BIM?
- Which are the implementation areas in the AEC industry?
- Which is the current status in BIM worldwide?
- Which benefits and challenges does it have to the AEC industry?
Regarding to the laboratory model, the objective, will be defined weekly by professor Gregory Harrington and the team members. However, the broad objective is to have a 3D accurate model of the current status of facility by the end of May, introduce different design options upgrades to it and provide a realistic walkthrough video of it.
There is a set of landmarks that are worth to mention in order to understand the evolution of buildings modeling’s software through the history that have made possible development of BIM. The following software that are going to me mentioned made a significant advance in terms of building digital representation and disrupted the traditional methods of representation and collaboration.
We could go back to 1962, to find one of the very first ideas that contained some basic ideas of the main BIM software nowadays. Douglas C. Englebart says in his paper Augmenting human intellect:
“The architect next begins to enter a series of specifications and data–a six-inch slab floor, twelve-inch concrete walls eight feet high within the excavation, and so on. When he has finished, the revised scene appears on the screen. A structure is taking shape. He examines it, adjusts it… These lists grow into an evermore-detailed, interlinked structure, which represents the maturing thought behind the actual design.”
This statement suggests the idea of parametric design of objects that will come several years later and will revolutionize the graphic representation methods of buildings.
Two main methods of shape digital representation started to appear and be developed in the 70s and 80s. Constructive solid geometry (CSG) and Boundary Representation (brep).
In 1974, Building Description System (BDS), which was design by Charles Eastman, was the first project in which a database was created. This software was the first one in creating a library of elements that could be selected and added to the model. There is not actual prove that any project was realized using this software, but Charles Eastman’s project contained a future vision that would definitely anticipate the future path that software development companies of building modeling will follow.
In 1977, Charles Eastman made another step forward and he developed Graphical Language for Interactive Design (GLIDE) at CMU. This project showed many characteristics of the current BIM platform.
Gábor bojár, founder of Graphisoft co. developed ArchiCAD in Budapest, Hungary in 1982. ArchiCAD will become later the first BIM software used in a personal computer.
Same decade, 4 years later, in 1986 GMW Computers developed The RUCAPS software system, which was the first one that introduced the concept of temporal phasing of the construction process. It assisted the construction phasing in the project for the construction of Heathrow Airport’s terminal three.
In 1995 it is created the International Foundation Class (IFC) file format. A file format created to mitigate the collaborative inefficiency due to the use of different programs. This file format has continued to being adapted to make possible the BIM philosophy and its full collaborative approach. With this file format it is possible to go with one file from one BIM program to another.
In 2000, Irwin Jungreis and Leonid Raiz’s company called Charles River Software, developed “Revit”, which nowadays is one of the most extended software used for BIM implementation. By 2002 Autodesk bought Irwin and Leonid’s company and started promoting the Revit software. Revit would revolutionize the building information modeling world. Revit introduced parametric components that were created using a graphical “family editor” rather than a programming language like the ones used by the other BIM software at the moment. Moreover it allowed to include a time attribute to the components that provide a fourth dimension of time associated to the building.
Later in 2004 Autodesk released a new version of Revit that introduced collaborative disciplines (Mechanical, Structural, and Architectural) and made possible to model the different disciplines in different files being all of them linked and allowing a full collaborative work between them.
In 2012 was developed formit a mobile device app that makes possible to make conceptual starts of the BIM model in the mobile device.
Currently, software developers are doing research and developments related to augmented reality.
Building information modeling is a process in which information related to construction projects is created and managed. This information is generated, stored and managed through the use of Building Information Models. According to the National Institute of Building Sciences (2007), building information models are defined in the United States National BIM Standard V1, P1 (Jan 2008) as:
“A digital representation of physical and functional characteristics of a facility. As such, it serves as a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life cycle from inception onward.
A basic premise of Building Information Modeling is collaboration by different stakeholders at different phases of the life cycle of a facility to insert, extract, update or modify information in the Model to support and reflect the roles of that stakeholder. The Model is a shared digital representation founded on open standards for interoperability.”
BIM is therefore a modern process for the construction projects management. It can be defined as a combination of tools and methodologies. The tools are a group of software that are use to generate parametric models that can store all the information related to the facility during all the phases of its life cycle and provide a multidimensional visualization of the facility. And also the electronic devices that allow the users to create edit and visualize these models, such as computers, tablets, phones, geodesic tools, and others.
The use of these tools and the interaction between them and also between them and the users or stakeholders in the life cycle of a project are the BIM methodologies, which will be defined later in this paper.
Mark Bew and Mervyn Richards developed in 2008 “ The UK BIM Maturity Model”, also known as “The Wedge” (related to its famous shape) or the “iBIM Model” (which is the last level of the diagram/model). In it, they identify different levels of maturity of BIM in the industry. It could also been called a strategy model, policy model o industry roadmap.
In their model, they identify 4 different levels:
- Level 0: 95% produce 2D drawings lacking coordination, increasing costs by 25% through waste and rework. Uses CAD software.
- Level 1: There is a 2D and 3D spatial coordination that provides the potential to remove error and reduce waste and rework. There is still lack of a defined database.
- Level 2: Introduction of the collaborative aspect of BIM, 2D and 3D documents that are coordinated and database defined that enables a collaborative work between documents. Level in which starts the Building Information Modeling.
- Level 3: Full implementation of BIM. Fully integrated and interoperable BIM with the potential to mitigate risk throughout the process and increase profit through a collaborative process. Introduced construction project management in the process. Objective level for the BIM industry to reach, it needs standards to be defined (some of them already exist)
- “ UK BIM Maturity Model” by Bew & Mervyn Richards (2008)
The bellowing table summarizes the different softwares available and used as tools for Building Information Modeling grouped by categories. One of the most extended used software is the Revit package from AutoCAD and this will be the one that will be used and explored in this project, combined with Navisworks, also from AutoCAD.
|Sustainability||Construction (Simulation, Estimating and Const. Analysis)||Facility Management|
|Autodesk Ecotect Analysis
Autodesk Green Building Studio
IES Solutions Virtual Environment VE-Pro
Bentley Tas Simulator
Solibri Model Checker
Vico Office Suite
Vela Field BIM
Glue (by Horizontal Systems)
Vintocon ArchiFM (For ArchiCAD)
Building Information Modeling is considered as the next step of the computer designs development. What BIM actually does is to collect all the information of a facility in a single document or better called, in a single model instead of having multiple separated documents for different types of information. One of the main characteristics of BIM is the parametrical modeling, which is the practical essence of BIM. This type of modeling, allows a fast implementation of changes in the model so that, introducing any change in the “main” model updates the information in all the disciplines and information stored related to that change. Before BIM, any change would need to be done in all the different documents that are any related to the change. For instance, a simple example is if once all the drawings of a facility are finished and then somehow the dimensions of an element of the facility (a wall for instance) need to be changed, then with BIM, this can be modified once in the model and all the drawings will update this dimension.
Without BIM every single drawing in which this wall appears will need to be change one by one. As we can see, this gives an incredible improvement in terms of efficiency and it is thanks to the parametric modeling.
BIM methodologies can me characterized by the following points:
- BIM is a single data storage accessible and shared by all the stakeholders.
- Bidirectional processes: Automatic Feedback.
- Parameterized objects in the model
- Visualization versus Representation
- Efficiency of the simulation through all the life cycle of the project
One of the main characteristics of the BIM methodology is the use of a unique database, which is created based in a virtual space that stores all the information generated in the process of the project and that can be updated by any of the stakeholders.
This characteristic needs correct methodology to be done in order to take advantage of the benefits that it presents. This is for the stakeholders to be collaborative and compromise to keep the database updated and do not manage information separately from the common and unique database of the project. If the database is not taken care of and is not rigorously updated through all the project phases and steps, this characteristic will be being ignored and pointless.
The software used in BIM provides mechanized and automated processes that allow verifying the correct coordination between the several documents and data. Without BIM these verifications needed to be done manually going throw documents and data checking one by one, which has a much bigger rate of error.
Another property that BIM data and tools have is that they are bidirectional. This means, there is an automatic feedback between them. This makes possible to extract information from the central database, manage it and give it back so that that tools automatically verify that all the information is coherent and update whatever has been modified creating then a constant and continuous information flow.
BIM methodology is based on keeping this continuous information flow feedback that is why not every platform that is able to communicate with the BIM process is part of it. Only if the platform or tool gives back the information extracted and has a connection with the main database it will be part of the BIM process.
If this information flow and feedback is broken then the process is inefficiently implemented and the conventional workflow is been used in which the possibility of mistakes like lose of information or discordancy between documents increases.
The definition of the model elements and the relationships between elements and elements and the whole are defined in a parametric way. This allows coordination and management of changes starting with a user input and running a logic mathematical relation with the elements. Thus, elements interrelated are modified automatically when one of them is modified in order to make the mathematical logic relations established between those elements to be verified and keep the whole coherency of the model.
Conventional processes information is usually managed by text, graphs, or tables created manually and independently created by the technics using other original drawings or client’s demands. Thus, going back to the same idea that is in all the points above, if something in this original drawings is modified of the client demand is modified, then all the representations in the project will also need to be modified.
BIM goes some steps ahead with this problem. BIM moves from the manual and independent representation of the information to the creation of a single database in which all the information is related and automated thanks to the introduction of the desired characteristics by the user.
This working method, enables the creation of objects through the introduction of the characteristics of the objects, which are assumed and processed by the software that manage this information to create a visual image of this information introduced by the user. A simple example would be, introducing in Revit a wall that goes from the first floor of a building to the second one. This could be introduced as a new object type wall, then define the characteristics of the object that can be several: bottom and top constraints (first, and second floor), longitude, type of wall (defining material thicknesses and layers, etc.), once all this information is introduced the software gives you a visual representation of all the characteristics you have introduces and you can see 2D drawings of the element, 3D views, sections and realistic renderings of it. If any characteristics of the object are changed, then the visual representation will automatically update and with it all the elements that were related somehow with the element changed.
Another example of what this means in terms of advances over the traditional method is that, for the same wall motioned in the previous example, the conventional method will define the material of the wall with text, with BIM you defined this as another characteristic of the wall and it can be visualized in the model too.
Finally, another interesting characteristic of the BIM methodology and process is that it extends the operability of the project. All the information introduced and stored is used not only in the design and construction phases of the project, in which BIM provides new opportunities, such as the simulation of the construction process or the simulation of the facility itself and obtain information about energy efficiency or sustainability, but also, in all the life cycle of the project. The feedback and continuous updating of the virtual facility gives the opportunity to use in a very effective way all this information through all the life cycle of the facility helping to reduce cost in the operating and maintenance phase of the facility and even in the demolition phase.
McGraw Hill Construction conducted in 2014 a study about The Business Value of BIM for Construction in Major Global Markets and How Contractors Around the World Are Driving Innovation With Building Information Modeling. In this report the following statement is done:
“From the initial research conducted by McGraw hill Construction (MHC) on the use of Building information Modeling (BIM) in North America, conducted in 2007, the potential of BIM to support a transformation of the processes of design and construction has been evident. Further research in Europe, North America and South Korea over the next few years revealed that BIM was seeing wide industry awareness and adoption. Now in the first study conducted by MHC on some of the most significant construction markets globally, it is clear that BIM is beginning to fulfill its promise to deliver improved ways to pursue construction globally.”
This statement can give us an introductory view of how BIM is hitting the construction industry worldwide. It is obvious that the adoption of BIM is increasing in every country, and some of the data of the McGraw Hill Construction’s report proves it. The following image shows the percentage of contractors at a High or very high BIM implementation lever by countries in 2013 and the predicted by the contractors themselves for 2015.
- Percentage od Contractor at High/Very High BIM implementation levels (by Country). Source: McGraw Hill Construction, 2013.
As we can se, the implementation level increase predicted by contractors worldwide in 2013 was high in every country, reaching a 49% maximum increase and with a global average of a 32% increase. This means, that in 2013 the awareness of the potential of BIM was there, and therefore it still now in 2017. Moreover, although we don’t have specific data to compare the predicted values for 2015 with the real data we can expect that now in 2017, the adoption values can be around what was predicted for 2015 or even higher. This means that in some countries the BIM adoption by contractors reaches probably almost the 80%, and this values, are still growing year by year.
- Increase of BIM adoption predicted in 2013 by Contractor in a two-years period (by Country). Data source: McGraw Hill Construction, 2013.
As it can be seen in the graphs shown above, the BIM adoption globally, varies by country. These differences are due to several factors. An important one is the BIM policy and strategy taken by the different governments.
- Worldwide BIM adoption status background. Source: own elaboration.
Figure 7 above shows a visual background of the different international situations and approaches regarding to BIM adoption in the construction industry. The following paragraphs will give some information in terms of policies and strategies in different countries.
UNITED STATES OF AMERICA (USA)
In 2003, The General Service Administration (GSA) through its Public Buildings Service (PBS) established the National 3D-4D-BIM Program. Since then, this program has evolved into collaboration between the Public Buildings Information Technology Services (PB-ITS) and PBS, through its Governance Board. The program supports BIM uses across all PBS business lines.
GSA mandated the use of Building Information Modeling in the design stage of all the new buildings of the Public Building Service since 2006.
From 2007 and beyond, GSA requires a spatial BIM program as a minimum for the Office of the Chief Architect (OCA) for final concept approvals.
The Facility Information Council (FIC) began developing the National BIM Standard™ (NBIMS) in 2005 to improve the interoperability of BIMs. In early 2008, the FIC released NBIMS Version 1 – Part 1: Overview, Principles, and Methodologies for Public Use. That same year, in order to consolidate missions and streamline services, the buildingSMART alliance® began overseeing the standard after the sunset of the FIC. The mission of the FIC endures under the governance of the Alliance. The NBIMS-US Project Committee continues the important work of developing open standards and guidance documents for all aspects of building information modeling. In 2012 was released the NBIMS version 2 and in 2015 was released the NBIMS version 3.
In 2014 the European Parliament voted the directive called the European Union Public Procurement Directive (EUPPD) in order to modernize the European public procurement rules by encouraging the use of new techniques and technologies such as building information modeling for public works contracts and design contest. It recommends to all the 28 European Member States to encourage, specify or mandate the use of BIM for public projects.
In Norway, it is required the use of BIM in all public projects by the public construction and property management representative Satesbygg. The governmental BIM requirements combined with a construction industry that supports the use of BIM have made Norway to be successful with the implementation of BIM.
Denmark has a BIM mandate that requires the use of BIM for public projects since 2013 and the current stage of BIM maturity in their level of implementation is level 3. Denmark is another successful country in the implementation of BIM.
There is a public sector mandate in Finland since 2007. An it is madatory in Sweeden too by the Swedish Transport Administration since 2015.
Nordic countries are a successful example of BIM implementation and this can be due to their construction industry size, they have an advantage compared to other bigger industries such as the United States. Professor Arto Kiviniemi at the University of Liverpool says:
“In Finland, the Confederation of Finnish Construction Industries decided in 2002 that BIM is a core element of their technology strategy, and people simply agreed to start working in the new way. It did not require contractual changes as a small market forces you to work in a reliable way. In a huge market, where there are more potential partners, a bad reputation doesn’t follow you so much, so contracts are more important.”
United Kingdom (UK)
The past 4th of April 2016 UK applied a BIM mandate that requires the use of BIM at level two of maturity for every project in the public sector.
In June 2014, Sylvia Pinel, the Minister of Logement et de l’Égalité des territoires (Ministry of Housing), announced the intention to put in place a “French numerical strategy” with the possibility of making BIM mandatory in public procurement in 2017.
Later in 2015 the developed this strategy of modernization of the industry. A 3-year plan that wants to help to introduce use of BIM pro public projects and that is a transition to the final requirement of its use. France is now in a testing phase of the use of BIM for all public projects but is planning to require it between 2018 and 2020.
Since 2010 BIM started to be heard more strongly in the building and construction industry in Spain. After the European directive in 2014, like most of the European countries that had not BIM standards or strategies by then started considering the implementation of a BIM strategy to move forward a BIM adoption in public sector procurement. In 2016 was developed a provisional timetable with the recommendation of BIM in public sector project by March 2018, mandatory use of it by December 2018 and make mandatory the use of BIM in every infrastructure project by July 2019.
Germany is in a similar situation as France. Currently they are implementing a testing pilot phase of BIM adoption and they plan to require it for the public sector by 2020. The strategy is to use this pilot or testing phase to be able to identify legal and standards requirements for the right and effective adoption of BIM.
In 2011 the government Building Agency mandated BIM in building projects. In 2012, The Rijksgebouwendienst Building Information Model Standard, shortened to Rgd BIM Standard (Rgd BIM Norm in Dutch), describes the specifications of BIM extracts and accompanying deliverable files. Later in 2014 the Building Information Council executed a program to implement BIM in the Industry.
UNITED ARAB EMIRATES (UAE)
There is a BIM mandate since 2014 in Dubai that requires BIM adoption for all buildings of 40 stories or higher, buildings of 25000 square meters or more, and all project from international clients, all hospitals, universities and major public buildings.
In, 2014 BIM was used for the FIFA World Cup Stadium. A total of five new stadiums were built for the FIFA World Cup, and two were modeled using BIM techniques and software. There is a high adoption of BIM by contractors in the industry but there are no governmental mandates about BIM adoptions, neither national standard defined.
There are BIM standards developed since 2016 and the Public Procurement Service requires BIM mandatory use for all projects of 50 million dollars or more and also for every project within the public sector.
A pilot process was started in 2010 for public buildings and in 2012 it was released a set of BIM guidelines and the Government Buildings Department started to study the possibility of adopting mandatory BIM adoption in some projects. An update of BIM guidelines was released more recently in 2014. BIM is being used but is still not mandatory.
Strong use of BIM and strong encourage by the government to use it. A BIM action plan was started in 2012 in which BIM standards were developed and the government started encouraging the adoption of BIM for construction and design projects. It is not mandatory for any project yet.
They started in 2010 a BIM strategy with the objective of provide all resources, tools, incentives and information that would be needed to implement BIM in their projects. The goal that was set for the 5-years strategy at the beginning was to reach 80% use of BIM in the construction industry. They have BIM guidelines developed and there is BIM electronic submission requirement for some projects since 2013.
The Building and Construction Authority (BCA) promoted the fist world’s implementation of BIM electronic submission. Since 2014 it is mandatory the use of BIM in the public sector.
A growing construction industry is taking more and more adoption of BIM. Use of BIM is not mandatory yet but there are standards. However, there are provinces with different guidelines or standards.
In 2014 it was initiated the BIM South Africa project, an Organization that promotes use of BIM through social media. Government has not taken a driving position on BIM practices and there is therefore a lack of standards and guidelines that makes more difficult the efficient adoption of BIM in the industry.
BIM roadmap established since 2014 for a period of 6 years. With a set of goals such as, Foster engagement from government, industry and academia by promoting BIM in Canada, develop guidelines, protocols, technical codes and standards to facilitate and standardize the use of BIM in the Canadian AEC community, develop training and educational programs to develop the core BIM capabilities in the Canadian AECOO community and create and implement collaborative project delivery environments that foster the use of BIM in the Canadian AEC community.
BIM can be used through all of a project life cycle as it has been already mentioned previously in this paper. These different stages of implementation of BIM, or different areas in witch it is implemented can be defined as what is know as the Building Information Modeling dimensions, which start in a known 3D dimension to a 7D.
- Building Information Modeling dimensions. Source: own elaboration.
This dimension consists of the 3D integrated modeling by the different disciplines (Structural, Mechanical, Plumbing, Electrical, Architectural) and the updating of the model through all the life cycle of the facility. What BIM does here is to model the shape of the building and to assign the information to each element that defined it in the level of detail desired. The 3D dimension is the first one and all the other dimensions will use what is created in this dimension. Somehow, it can be said that this is the most important dimension, since it is needed for the rest of them. The model created here will be the BIM core.
Within 3D BIM not only the construction of the 3D model of the facility is included. The following task, activities or techniques are included in what is known as the BIM 3D:
This makes possible to visualize how will it be to walk through the facility, which is helpful for designers, contractors and also owners to identify and solve problems that without this would not be found until the facility is constructed.
The conventional approach of construction projects could lead to clashes between different systems of the facility. With BIM, all disciplines of the project are coordinated and it can be performed a clash detection, in order to make sure that elements from different systems do not interfere each other. With the traditional approach these clashes were detected on-site and working. This cased delay, and the need of quick decisions to solve the problem and avoid to extend the delay witch is traduced in cost loses. BIM clash detections can help to avoid these problems on site, detect any clash before start working and make the right decisions to solve the problem minimizing cost of it and avoiding delays in the construction.
This is probably the least innovative tool or area of implementation of BIM because there are others software that do not belong to the BIM concept and can provide 3D project visualizations too. However, the integration of all the disciplines and the parameterization of the elements make a difference from the rest of software.
Project Visualization can be a successful marketing tool used by all the parties involved in the project. And it can also be helpful to give an easy understanding of the design to the owner.
Virtual mock-up models
Sometimes in large projects owners ask for mock-up models to better understand and visualize the design and then be able to make better decisions about the aesthetics and functionality of the project. BIM 3D Modeling provides virtual mock-up that can be used as a substitute of physical mock-ups models.
There is a very high level of information within a BIM 3D model. This level of detailed and accurate information provides a bigger assurance that prefabricated elements will fit on-site. Therefore, prefabrication can be used with a higher confidence, increasing work off-site, reducing time and cost and risk.
BIM 4D introduces a time dimension to the 3D space modeled. It enables the introduction of project scheduling techniques to the BIM model. This means that contractors, designers and project owners are able to plan space utilization, sequence construction processes and allocate resources effectively and manage risks, supply chain and cost allocation efficiently using BIM.
Therefore, BIM 4D provides Model-Based Schedule, project-phasing simulations, lean scheduling and visual validation for payment approvals. From integrating information on construction sequencing, conflict detection and resolution to construction systems design and material planning and management, this helps to ensure that the construction processes remain streamlined and efficient through site logistics and installation scheduling.
Construction phasing simulation works in favor of contractors to help them visualize logical challenges such as “just in case” scenarios, macro-level construction phasing strategies, out-of-sequence work, scheduling conflicts between multiple trades and many more. It also helps to work out possible solutions to these challenges and achieve an optimized construction schedule.
Having the schedule of the project connected to the 3D model makes possible to provide a visual simulation of the construction process of the facility, what it has been called schedule simulations. These schedule simulations are helpful for contractors and designers to show the owners and interested parties a better understanding of the construction process and sequence of phases and activities.
This dimension includes everything related to cost control and estimating. Every element represented in the model can be assigned a cost and this makes possible to do detailed cost analysis without an extra work, since all these cost are obtained directly from the model. This tool is oriented to the optimization of projects profitability.
It accelerates the quantity takeoff process and enables “Real Time” cost estimating.
Take-offs in projects are have been conventionally performed manually by contractors. This leads to the possibility of error. 4D BIM makes possible to obtain all this information with a higher level of accuracy in an easier automated and faster way. With BIM, the model can rapidly generate reports with all the essential estimating information needed. This reduces the possibility of error in the estimate and makes it much more accurate without an extra work.
Also, every change can be easily introduced and all the information is updated keeping initial estimate and real time estimate, which helps the cost-control process.
‘Real Time’ cost estimating
Since the previous dimension is time, the model already has sequences of time associated and this fifth dimension enables the model to provide real-time cost estimating, since if has information about cost data and also time data. However, it is important to point out that the overall project estimate will still need an expert (cost estimator) to interpret the information that can be obtained from the model and manage it.
This dimension includes applications related to the sustainable design of the facility. BIM makes possible to make simulations in which materials behavior can be tested and the design can be optimized in terms of sustainability, reaching design od energy efficient facilities and with net zero energy.
Simulations can be used to make several sustainability analyses such as Energy Analysis, heat and loads calculations, fire and smoke modeling or wind energy and pollution dispersion.
The seventh dimension includes tasks and activities related to the facility management and maintenance. It makes reference to the logistics of the project through all its life cycle. Consists of the management of all the project information through its life cycle and the use of this data to maintenance planning, inspections, and remodeling or even demolition, always trying to optimize the performance of these activities or processes.
It helps facility managers to quickly take informed decisions regarding spatial requirements, repair and maintenance, energy evaluation, and maintenance of HVAC systems.
BIM can develop lifetime virtual building model to allow extraction and tracking of relevant asset data such as component status, specifications, maintenance/operation manuals and warranty data, providing easier parts replacements, and a streamlined asset life cycle management.
Also, sensors can be installed an record relevant data that feed back the information model in order to monitor the building and optimize the performance needed en each phase to optimize cost efficiency.
After describing Building information modeling in terms of methodology and also in terms of applicability areas for the Architecture, Engineering, and Construction (AEC) industry. It can be observed that it brings to the AEC industry several advantages compared to the conventional approach of managing and designing project. All the advantages that it presents can be resumed in three main big advantages, which are:
- Communication Improvement
- Reduce risk of error and rework
- Optimization through all the project life cycle
This is one of the most important advantages, and it is a base for the rest of the advantages to come. The BIM methodology improves communication between all the parties involved in the project and makes easier to share information. BIM accelerated the communication process making possible a real time communication of any important information of the project. Communication routes are easier with BIM and it reduces the possibility of missing information in the communication process.
Humans tend to make mistakes, computerization of any process or activity performed previously by humans will reduce the risk of error in the process/activity. Moreover, BIM tools of auto-check coordination between different sources of information makes possible to detect any possible wrong information introduced in the model in the moment that it is introduced. This means that any mistake can be detected in the correct moment so the waste of time fixing this mistake is minimum. BIM reduced considerably the amount of rework done, exactly because of this, because it is able to recognize information introduced that is not concordant with everything else in the model.
The other two above advantages mentioned joined with many other tools of BIM make that the whole project process is optimized with BIM methodology. All the possibilities that BIM presents that have been mentioned before in this paper, such as cost efficiency, scheduling simulations or energy efficiency analysis are traduced in improvements in the project evaluating different scenarios, selecting the best one. The whole project is optimized in terms of energy cost, quality and definitely in terms of project value.
We could highlight four big groups of challenges or counter effects related to BIM adoption in the construction engineering and architectural industry. These are:
- Need of standards
- Need of skilled personnel
- Organizational or implementation issues
One of the most important challenges for BIM adoption is to establish Standards and regulations. Procurement regulations are done
The adoption of BIM implies considerable investments in software and tools for the industry’s companies. Some of these companies are worried about the return on the investment of the BIM implementation. Although the project life cycle processes would increase their efficiency, for some small companies that usually work for small projects the efficiency improvement in the process is not costly efficient. The cost saving promises of BIM adoption for AEC projects could be subject to company or project sizes.
Another important barrier to implement BIM is that in order to maximize its potential benefits and improvements in the processes, all the parties involved in the process should have BIM knowledge. This can also be traduced terms of cost of the implementation, since the transition from the conventional approach to the BIM approach requires training in in order to make sure that all personnel involved in the BIM process is skilled.
The following BIM case study consists of the update of a Revit model of the Water Resources Engineering Laboratory of the Department of Civil and Environmental Engineering at the University of Wisconsin-Madison. The Revit model development will be done by a group of four students of the University of Wisconsin-Madison and it will be supervised and managed by the professor Gregory Harrington of the Department of Civil and Environmental Engineering.
Starting from an initial Revit model previously done by another student, the new BIM team will be responsible for the review of the existent model and the correction, adaptation, and addition of whatever is found necessary. The new BIM team will also be responsible of extending the west limit of the model and introduce in it the correspondent rooms that are within the new west limit defined. Once the new rooms are added to the model and the review of the existent model is done, the new BIM team will start working in the development of different solutions for the introduction of new equipment to the laboratory that will require relocation of some existent equipment and redistribution of the space.
Finally, once the different design options are defined and modeled the students will also generate walkthrough videos that could be useful to be shown as a marketing tool for potential donors.
The laboratory that is going to be modeled is located in the basement floor of the Engineering Hall building of the University of Wisconsin-Madison.
- Facility location: 1415 Engineering Dr. Madison, WI 53706, USA.
The main sources of information as a starting point are the existent Revit model, the set of original drawings from 1961 converted to TFI format and the laboratory itself to check any discrepancies between the drawing and the Revit model or any information that is not introduced in the model and can not be found or understood in the original drawings.
The existent Revit model
The existent Revit model has modeled in it part of the corridor that gives access to the laboratory, the laboratory room and the two east rooms accessible from the laboratory room. There is a pipeline that goes from the laboratory in the basement to a tank in the third floor of the building. The rooms through which this pipeline goes are also in the model and the tank room in the third floor as well. (Figure 8)
- 3D view of the initial Revit model.
The model is compound by the following elements: walls, concrete columns, pipe system (pipes, pumps, third floor tank…), stairs, doors, floors, and some equipment (big flume). No mechanical system is in the model.
The 3D model has also a set of drawings defined with main floor plans and sections. (Figure 9)
- Sample of drawings from the set of drawings of the existent model.
The original 1961 drawings
The original drawings of the whole project in 1961, when the part of the Engineering Hall building that contains the laboratory was built, are available in TFI format (Figure 9). There are a total of 4 sets of drawings, the structural set, the architectural, the mechanical and the electrical.
Initially, it will be inly used the architectural and structural set. If the modeling progress is fast it might also be used the mechanical set in order to introduce the mechanical system in the model too. No electrical system will be modeled; therefore the electrical set will not be used. The drawings are for all unit #3 of the Engineering Building, which is part of the east wing of the current building. However, only the part of the basement laboratory will be modeled. (Figure 10)
- Title sheet of the Original 1961 drawings available of the facility to be modeled.
- Basement architectural floor plan. Highlighted the section to be modeled.
Access to the laboratory
The laboratory is currently used, however it will be accessible for the BIM team to make any on site measurements that need to be done to verify dimensions in the model or in the drawings.
- Laboratory current status photographies.
- Modeling sloped floors
- Defining new materials
- Dimensions incoherencies between drawings and facility
- Initial model mistakes (Dimensions, elements locations, tools used for modeling elements)
- Lack of communication with the previous model developer
Characteristics not applied:
Bergin, M. (2012). A brief history of BIM. Retrieved from http://bit.ly/1gG8lSj
Bhatia, N. (2014) ‘Dubai Municipality seeks private sector support on BIM mandate’. [online] available from < http://www.bigprojectme.com/news/dubai-municipality-seeks-private-sector-support-on-bim-mandate/[01 November 2014].
Eastman, C., Teicholz,P., Sacks,R. and Liston,K. (2011) 2nd edn. ‘BIM Handbook’. Hoboken, New Jersey: Wiley & Sons publishing.
STATE OF THE ART.