The standard of the future!
Within the construction industry BIM has become a concept of its own. Nowadays we want to BIM projects or people are talking of setting up a project in or with BIM In practice this means that in most cases drawings are still done in complete 3D instead of 2D. This 3D model is subsequently sent to all other project advisors that use the model as foundation for the making of their own drawings and calculations, while the architects continues designing in the basis model. At the moment every advisor still works in his own version of the model and there is not yet a single BIM within the project.
What is a BIM?
BIM represents a new way of project organization and communication. The core of a BIM oriented process is one central model in which every advisor saves the needed information that is necessary for that design phase or the eventual execution. The main advantage of one central model is that the tuning between the different advisors is virtually flawless. The central model is an information model with as basis a 3D model of the design to which the different advisors can add various characteristics and minimum demands. Since all information regarding a certain construction component in the model needs to be saved as characteristics of the construction component, there can no contradictions within and this means there it is not necessary for different sets with drawing or reports to be spread to find the right information out of every document. The model will also help the project team prevent errors. If fire separation is added to the design, then all construction components that are places on this fire separation also need to have this minimum fire-resistant demand. If an element in the design does not meet this demand then the BIM will note this and make a mention of it.
By now everyone agrees that we have reached the technical point where a design trajectory with a BIM is possible for every project.
Computers have sufficient calculation power for the large 3D models, software solutions exist and internet speed are sufficient for the quick exchange of data. Through the use of one central model BIM as of yet still causes three bottlenecks that need to be agreed upon between the parties before the BIM will become the standard for the future. What follows is the three points with an explanation of what still obstructs the application of a BIM.
- Which standard will apply?
The information in a BIM need to be read by everyone in a uniform way and if information is added then that this also needs to be done in a uniform way, so that other advisors can draw their conclusions out of this. This is only possible if there is a standard in which everybody works and codes information.
At the moment this standard is not there yet. There are coding systems to classify the elements and materials, but these are not (yet) sufficient to classify all construction components completely and uniformly. Even more important is that a BIM ensures the addition of extra information to the construction elements that apply to multiple advisors. The type of material and the mass of a construction element are for example needed for both the constructor as well as for the installation advisor. The fire penetration, U value, ZTA values and the like are also applicable to multiple advisors.
All these characteristics can be added to the elements, this can be done in a manner of speaking as just one text - Material: Concrete B35, reinforcement Fe360B: 60 kg/m³ etc. A different advisor could do little with this unless he runs through every single construction element and checks what is listed in it, which is a time-consuming job. One standard means that a BIM is equipped in a way that not just the type characteristic is defined and coded in a uniform way, but also that the placement within the model and the way in which the quantity of the quality is defined is completely uniform. Eventually there will have to be a sort of NEN standard for the definition of characteristics within a BIM.
Of course there have been projects in which a BIM was applied successfully. These were mostly either large projects where it was possible to create an own ‘project standard’ up front with the advisor team to ensure a uniform data exchange, or they concerned a developing contractor with his own standard which he applied up to the execution. At the same time work is being done to several material libraries in which extra characteristics are also added. Eventually these developments will lead to one standard with a uniform exchangeability of information.
- Who will be the administrator of the model?
At the moment every advisor makes his own drawings, calculations and advice reports. In the end a design consists of several sets of drawings and reports (architectural, construction, installation drawings, acoustic, durability construction report, specifications etc.). Every advisor has the information for which he is responsible completely in own management and supplies this to other members of the project team. If we are to reach one single joint model then every advisor will also become next to partly responsible also a part owner of that one central model.
The question that is conjured up here is: who will ‘host’ this model and who will control the flows of information, the possible conflicts that will arise and the needed actions for this? The architect seems to be the designated person for this at first, since he puts in the basis for the design and the BIM.
Here hides a risk factor, however. The architect would need to manage the model as well as take care of his own input. In the case of a conflict between the input of different advisors it is possible that the architect (as advisor and manager of the model) is not fully able to act independently. Example: An architect should not just be able to change the characteristics of a material if other advisors have set minimal demands to them. For large projects an independent manager of the BIM can have an added value for managing the model on completeness, correctness and conflicts.
- How will the income model of the advisors look like?
A final, not quite unimportant, element concerns the income model of the advisors. A new working method will only work if the activities and responsibilities are balanced with the compensation that the advisors will receive. In the design process with a BIM the existing remuneration models are outdated. This is especially because a BIM causes the following changes:
a. Work activities are shifting
The work activities of the advisors are shifting in the design process. While the main efforts of an advisor in a traditional design are with the Definitive and Technical design, with a BIM oriented design the phases Sketch and Predesign count much more because the initial activities (the setting up of the model) demand much more work with a BIM. Eventually a portion of these efforts pay off in the phase Definitive and Technical Design, but in total it will demand a larger effort of the advisors (see figure on the following page).
b. Responsibilities c.q. liability
BIM opens up the possibility to add this information and with the help of standard libraries this will happen too, but who takes the final responsibility for the correctness of this information in the execution? The advisor that (indirectly) supplies this information or does the executing party has a controlling function in this in the end? It is not clear how the liability of the advisors will end up exactly because of the additions of extra information in the model. It is possible that for the executing party a separate ‘procurement BIM’ will be made out of the complete BIM in which all extra information is taken out so that the danger of liability to the advisor is restrained
Finally there is also the fact that we are eventually heading to one model for which multiple advisors will supply input, it needs to be clear who will be responsible (and thus liable) for what information. All the more reason to have an independent BIM manager that looks after this. Depending on the responsibility and liability that the advisor takes here, the remuneration will need to be adjusted for this. For the advisors there will need to be a new remuneration system, that is also accepted by the clients. In all likelihood the advisor costs will increase (especially in the early phase of the design process), but the client will earn this back in the planning and the reduction of the risks and failure costs.
BIM will become the standard!
Eventually every project will use a BIM or a derivative form of this. To put things in perspective it is important to note that a BIM means a shift within the process that is larger than the step of the drawing table to the drawing on the computer. It does not just concern a technical adaption in the design process, but also an adaption in the collaboration, the organization and sharing of information. In the shift of drawing table to computer many agencies have looked for the best approach and the standard of working. These agencies have had to pay quite a bit of apprentice fee, but this pioneering phase has lead to the fact that every project is now developed with a CAD program.
The construction chain has some final hurdles to take before it arrives at a standard and working method for a design process that is accepted by everyone in which all possibilities of a BIM are utilized. In the short term there will be some large steps which will improve the design tuning especially. The upcoming time a lot of pioneering work needs to be done in which it is important that the parties are open to the sharing of ideas and the information between networks. Even within IGG Bointon de Groot there is belief in the possibilities of a BIM within the cost field. IGG develops a calculation package (BimCalc) to set up a cost estimate of a BIM model within Revit.
The article was published in the IGG Handboek van de gebouwde omgeving 2012 and was posted with the permission of IGG. This article is also available as a PDF file.
About the authors
Guido Leenders is founder and director of Invantive Real Estate solutions. Invantive is a supplier of solutions for real estate developers and project-driven companies. Invantive has developed BimCalc, the plugin for Revit, together with IGG. guido.leenders[a]invantive.nl
Arno Vonk is director and co-owner of IGG Bointon de Groot. As an economic construction advisor he has worked on the research of the possibilities of BIM within the cost subject area. He is also the founder of the Revit plugin BimCalc. For more information please visit www.bimcalc.nl