BIM Serial 003: From a computer model to the real building

So far we have discussed the BIM concept in general and what does BIM mean to a consultant or an engineering office. Now it is time to make the move from the computer model to the real world.

Modelled to the last detail

In a typical construction process, the engineer is responsible for the conceptual design covering the materials to be used, their amounts, sizes and general arrangement. In other words: construction documents. However, before we can start actual fabrication or construction, somebody still has to define all the details like exact reinforcing bar arrangement, connection details for the structural parts, details for the HVAC etc. Not surprisingly this phase is called detailing. A detailer adds to the model all the bolts, stiffener plates, creates rebar pending schedules, and may also utilise building information models from different disciplines to detail, for example, connections between HVAC and structural elements.

Once the detailing has been completed, the model looks “as-built,” including even the smallest details. Since the model becomes very much like the building to be built, some issues to affect its construction will most probably become noticeable. This is one of the main benefits of BIM: these issues are found out in the model and not at the construction site, which often happens in a conventional drawing-based process.

A very important criteria for selecting a BIM application for fabrication and construction is to make sure that it is capable of holding all necessary building details. The application should not become slow or its data files impractically big no matter how complicated or large a building is.

From the model to the real world

So now the building is nicely modelled to the last detail. All the constructability issues within and between disciplines have been solved. It is time to start building for real.

The traditional process is to print out hundreds or thousands of drawings and deliver those to the contractor. The main contractor then uses these printed documents to build the building either at the constructions site or using various subcontractors like fabricators of pre-casters.

The BIM process aims to make the design and the construction more integrated:

1) In addition to the drawings, the model should be one – and actually the most important – deliverable from the consultant to the contractor. Let’s leave the legal and responsibility issues aside for the time being.

2) The 3D BIM environment should be used as a basis for all communication between the consultant and the contractor. It is much easier than looking by 2D drawings.

A modern fabrication facility includes computerised (CNC) fabrication machinery and IT-based material management. A BIM must integrate with those to avoid “print out and key it,” as far as possible. CNC data shall flow directly from the model to the controls of the fabrication machinery. The same applies to the information transfer between the model and the material management and procurement systems. Every “print out and key in” phase creates a risk to make mistakes. Another big benefit of BIM.
BIM integration does not end at fabrication. Information shall also flow directly between the model and construction site equipment used to measure and control the physical locations. Let’s return to the work on site in more detail in the next issue of Roof&Facade.

Ari Nassi@Tekla

BIM Serial 002: BIM arrives to the Engineering Office

In the June issue of Roof and Facade’s BIM Corner, I wrote about how Building Information Modelling (BIM) helps to integrate the fragmented construction processes, bring cost savings and improve efficiency. Let’s now have a closer look on what are the major benefits you can expect from BIM based design.

Faster take-off

Most architects use 3D tools and can provide a 3D model, in some format, to support their architectural drawings. Engineers may utilise this information and use it as reference models whilst creating the structural engineering model, or directly convert it into an engineering model thus integrating the work process between the architect and engineer.

Automatic drawing and material lists production

Models produced by the BIM process are not “drawn”, but actually contains all the construction components and material as a computer-model simulation. From this model you can automatically print out all the required drawings and material lists. All the measurements and material lists will be correct since they are extracted from the accurate finite model. And the best part is still to come – any changes you need to make, and you know there will always be changes, all you need to do is to simply amend the model, and all the related documents, including drawings and material lists, are automatically updated.

Easier Analysis & Design (A&D)

Now that you already have the model, which you have created for conceptual design, there is no need to create another one for Analysis and Design (A&D). Within applications such as Tekla Structures all you need to do is to simply apply loads into your conceptual model and run the analysis by using your preferred A&D software from an extensive list of applications. And the benefits do not end here, since your loads are intelligent objects in the building information model they will stay there and can be reused at any time. When you modify the model, loads connected to the structural parts will follow the modifications and the re-running of the analysis results is easy at any time.

Design coordination in 3D environment

You may integrate your structural, HVAC, piping and other models into a single environment which becomes real-life working 3D model of the complete building. You can navigate around the structure, check any construction details and consider the overall constructability. This is much easier and interesting than trying to do the same based on a pile of 2D drawings. Communication is a major part of design coordination and your BIM model becomes the preferred communication tool, where you can view the model on the meeting-room wall or share it over the internet. Even complicated issues are easy to convey when discussed within the 3D model.
So what is the end result? Faster and higher-quality designs, where you can detect and correct all mistakes and most of the constructability issues, which would become very costly if only noticed a few months later at the construction site. In other words structural engineer has added more value to the design compared to the traditional drawing based process and his/her role has become more important.
Any comments or feedback you may have on my BIM Corner writings, please drop me an email.

Next time we will look how BIM can benefit the construction process downstream in fabrication.

Let’s BIM!

Ari Nassi / Tekla
ari.nassi@tekla.com

Contents of B & I (Vol. 19 No. 3 (November/December 2009))

http://www.b-i.com.my/

BIM Seril 001: What is BIM?

What is BIM?

Let’s try to answer this question.

Building Information Modelling (BIM) is a computer model simulation of the construction process. All the elements and parts of the building are presented in a 3-dimensional, very visual “as-built” format. Simulation does not only include the physical appearance, material and components, but it also includes the construction time line. You can see the building being constructed on your computer screen.

Computer simulation is applied for various purposes, such as product development, manufacturing, business cases, training, test flights, F1 car design, and so on. The list is endless. Computer simulation is cheaper than the real thing and you can try new ways or designs that you would not dare to try out in the real world. You can innovate; look for alternative, better ways without risking too much money or anybody’s safety.

The construction process is traditionally very fragmented with each discipline, from engineering to the site management, mainly looking after optimising their own work, relying on paper documents produced by previous parties within the process. They may be using 3D technology, but in isolation. Collaboration is mostly based on 2D drawings and text documents. BIM’s promise is to integrate this process. Another widely promoted concept is IPD, Integrated Project Delivery.

BIM enables seamless collaboration where each discipline adds and enriches the information within the model. No information is lost, and it is all the time easily available for all the parties involved in the construction process. The model holds information like approvals, modifications, schedules, materials, loads etc. Every piece of information is also stamped by time and author for the record.
Enterprise Resource Planning (ERP) and Material Information Systems (MIS) revolutionised collaborative work practices in manufacturing. The results were dramatic. Those who took advantage of this new technology early, saw massive increases in productivity and quality. Those who were late to adapt lost out and many did not survive.

BIM enables collaboration in the construction process. In a BIM environment, all participants in the construction process such as the owner, developer, project managers, consultants, contractors, subcontractors and facilities management, have access to the always up-to-date design, cost and scheduling information at the same time.

Would you rather look at a 3-dimensional model than a 2-dimensional drawing when discussing the details of your construction? Through a building information model it is also easy to identify and correct possible mistakes and problems in the planned construction – before anything has been fabricated or installed at the construction site. The cost of modification in the design and planning phase is only a fraction compared to the modification cost when the actual piece of the building has already been produced.

The key elements of BIM are design, that is Architectural, Structural and MEPF (Mechanical, Electrical, Plumbing, and Fire protection), as well as Scheduling and Costing; all being integrated into a single building information model.
Eventually BIM can save you thousands of working hours and costs through improved efficiency, avoiding mistakes, and reducing wastage.

So now you know BIM!

Ari: Inspiring continuous learning at workplace

To access the online story, click
HERE

Ari Nassi speak on BIM as a solution for sustainable construction and maintenance

ICA BIMARC 09 was a 2-day seminar on Building Information Modelling and Sustainable Architecture. The seminar organized by Infrastructure & Construction Asia was held at Prince Hotel in Kuala Lumpur 19-20 August 2009.

Tekla (M) Sdn Bhd Managing Director Ari Nassi presented a paper on “BIM as a solution for sustainable construction and maintenance”

To view the paper presented, click HERE