BIM for Contractors - Group E

Integration of the design and construction phase is a realistic and obtainable goal with BIM software. This results in any errors or foreseeable shortcomings being brought to light before and during the design phase. A Design build project makes this early integration of BIM software easier due to the general contractor being involved from beginning but projects are not always design build.

BIM tools help construction in areas of estimation, construction planning, fabrication and procurement. With the use of clash detection, contractors are able to quickly identify where objects collide or do not allow adequate access for insulation and maintenance. This feature is far better and faster than overlaying the traditional drawings to determine where design errors occur. The result of this clash detection should prevent most design errors from carrying over to the construction phase.

The use of BIM provides a unique benefit for estimators performing quantity takeoffs and cost estimates. Information for material and component quantities can be quickly put into schedules and understood so proper quantities are ordered. BIM lacks the capability to identify existing conditions with the site or certain materials, which provides a more accurate price due to the incorporation of location and demand.

Offsite fabrication is becoming more and more popular because of costs and risks that arise with site fabrication. Contractors using BIM to communicate to fabricators ultimately save time and reduce errors due to the accuracy and universal language of BIM. As a result of the fabricators being involved earlier in the construction process, more errors will inevitably be caught or avoided. 

BIM tools for construction offer a wide range of uses throughout the entire project and can save time and money when implemented from the beginning of the project. The ability to perform tasks in estimation, construction planning, fabrication and procurement will only help its continued raise in popularity.

Chapter 6 - BIM for Contractors

For this week’s blog posting, my group (group E) was assigned to read Chapter 6 - BIM for Contractors. In this chapter, the handbook gives a really detailed introduction about how BIM could help contractors during construction process. This chapter contains a lot of information about new software that could help contractor to save their time and effort. I will introduction few of them in my post.

This chapter made a discussion about the various types of application areas that BIM can provide the contractors benefits for their special needs. The one I found interesting was the reduction of design errors using clash detection. Clash-detection software provides much more advantages than traditional 2D coordination methods. The standard way detect a clash was to put all the drawings on a light table and let a person to check to see if there are any problems. This method sometimes led to a lot of human error which could only be seen doing the actual construction. The 3D clash detection relies on 3D geometry model to detect a large amount of clashes, this technology would reduce the human error to the minimum, which in the end, will save contractors a lot of time and money. And it is also much safer.

       Another section I found very interesting was the import of the 4D model into the modern construction process. Different than 3D model, 4D models would be really helpful during the community forums since it could show people clearly how a project would impact traffic, environment and their daily life. 4D models could also help project managers to compare schedules and track construction process, compare the actual construction field to the 4D models, project managers could easily check the project status to see if it is on track or behind schedule.

       BIM would give contractors so many new technologies to help them save money and time, could also move the constructions much quicker and more efficiency which can take the construction process into the next level. BIM models is not particularly perfect, but we would definitely see more and more companies and firms using BIM, and moving completely into BIM construction world is just around the corner.

Reference:

Chuck Eastman, Paul Teicholz, Rafael Sacks, Kathleen Liston; “Bim Hanbook, a Guide to Building Information Modeling for Owners, Managers, Designers, Engineers, and Contractors” Second Edition 2011

Comments On:

Dongyan Qi

I personally like to use Google SletchUp too, it is much more straight forward to me compare to other sketch software. The change from 2D model to virtual 3D building model is really a revolution, is changes the way that how people demonstrate a structure. The advantage of integrated project delivery is also good for all parties involved.

Stephen Bartal

Stephen, I really like the part that you put your own story about the Revit and AutoCAD, very interesting. I did not know about this function about Revit before, I used to spend hours making small changes through the project, definitely will try the parametric modeling function next time. 

Chapter 6 - BIM for Contractors - Planning Construction

Planning construction involves sequencing activities in space and time, like the procurement of materials, labor and other concerns. This was typically represented by bar charts, and the BIM handbook claims that such a method is “unable to show how or why certain activities were linked in a given sequence; nor could they calculate the longest (critical) path to complete a project.”

Image 1: A Sample Gantt Chart

Today, we now use software such as Microsoft Project, Primavera or P3 to create comprehensive schedules (or gantt charts) which display the steps of procurement and construction, linking every task and sorting by the most critical. A specialization program, such as Vico Control, is better suited to building construction by enabling schedulers to do location-based scheduling and allow multiple teams to do repetitive work in multiple locations. Even so, only a person with sufficient familiarity with the project and with scheduling can properly evaluate a gantt chart and determine if it is a feasible schedule.

The article points to a current dilemma in which the methods we use today still do not properly capture the spatial components of building construction. It seeks to solve the shortcomings of the modern way of planning project by suggesting two solutions. The first is 4D CAD, a 3D CAD software which incorporates a construction schedule and shows the day to day process of construction in a 3D model. Faults in the design and the scheduling can be observed in space and time, which helps designers and contractors identify the issues and allow them to devise solutions. The second approach is to combine analysis tools, BIM components, and construction method information to optimize activity sequencing. This conglomerate, as the handbook explains, incorporates spatial, resource utilization, and productivity information.

Image 2: A Sample 4D software

Of the two options described in the handbook, 4D simulations seem like the most sensible. The potential for collaboration and communication between owner, designer and contractors using 4D CAD is high. Contractors can review projects to determine the feasibility and can make accurate schedules based on the design. If a community or public project uses 4D CAD, the layman will be able to understand the project may impact his day to day life. Site logistics would benefit from the use of 4D CAD since they would be able to plan laydown areas, access points and location of large equipment. Last but not least, the 4D tool can compare different schedules and can easily determine if a project is early, on track, or behind schedule.

Reference

Chuck Eastman, Paul Teicholz, Rafael Sacks, Kathleen Liston; “Bim Hanbook, a Guide to Building Information Modeling for Owners, Managers, Designers, Engineers, and Contractors” Second Edition, Chapter 5; Second Edition 2011

Chapter 6: BIM for Contractors

The chapter discusses ways BIM can help contractors.  The chapter often mentions learning curves associated with new software and the need for early integration and collaboration; but with every topic discussed, it gets related back to being able to save the contractor time and money.

After reading this chapter, I realized why BIM has only recently caught on as a standard for construction management firms: there is a steep monetary investment.  There is a few pages dedicated to estimating and takeoffs, which cannot entirely be done in BIM.  To preform estimating, additional software or plugins are needed and a detailed model will be required. Learning curves associated with new software is an additional investment to firms.  According to the chapter, 91.6% of firms are made up of less than 20 people.  To purchase licenses to all the necessary software, getting their employees trained/hiring new employees who know the software, and making sure their computers are capable of running the software are all items a small firm will have to be able to budget for before committing to changing the way the have been operating.

Figure 1. Data collected from more than 750,000 firms collected from the US Census Bureau, NAICS 23-construction.

The chapter makes it very apparent why contractors should be using BIM, and the one I found to be the most interesting (as did Teddy Bruder) was the clash-detection abilities.  Clash-detection software is a much safer bet when it comes to potential interference with systems (whether that be other systems or building components), which can save a lot of time and money for all parties involved.  The standard way to tell if a system was ‘clashing’ was to gather all of the subcontractors’ drawings on a light table have a person try and determine if there are any overlays.  This opens up a lot of human error that will not be seen until the systems are installed - costing everyone money to reinstall/rework the systems to all fit.

Another section I found very interesting was the impact a 4D model has for the coordination and budgeting of a project.  A 4D model includes a time parameter that can highlight any shortcomings in the design that will conflict with other trades not starting on time.  Easton often states that this work needs to be done by the contractor, which will then be a great benefit to the architect and owner.  Again, relating back to how the contractor can save time and money through the use of a computer model vs hand drawn models.

Reference:

Chuck Eastman, Paul Teicholz, Rafael Sacks, Kathleen Liston; “Bim Hanbook, a Guide to Building Information Modeling for Owners, Managers, Designers, Engineers, and Contractors” Second Edition, Chapter 5; Second Edition 2011

Commented On:

Michael Kilgallon:
I've never heard of Tekla before: I'm going to guess that BIM was intended to originally help for coordination of the interior systems, which are pretty independent on the structure. Then again, I just read about how BIM helps contractors (chp. 6), so coordination of subcontractors is on my mind.

It's interesting that you pointed out that each program fits a purpose. Chapter 6 mentioned the constant need for additional software to do things such as estimating. Luckily, since AutoCAD has many of the additional program needed, using Revit would accept those plugins. Not sure how any of the other programs interface with additional software that may be needed.


Audrey Ryan 
It seems like so many aspects of the construction industry lags behind the available technology. I think it has a lot to do with the monetary investments needed on behalf of all parties. While a large architecture firm can make the investment into BIM, smaller subcontractors will still not be able to make that investment. Otherwise, I couldn't see how the old light-table checking for overlaps would have lasted as long as it has.

You brought up an interesting point about designers needing to trust the models. It are me think how many people will be working on this model: if the wrong one is chosen, the whole project struggles. Then instead of saving time and money, it ends up causing frustrations or blips during construction.

Brian Benson
I didn't realize that IPD was a result of Designers trying to pass the blame. I think it is a great incentive for designers to design buildings holistically (as we learned about in AE390/391) by being responsible for the project until its completion.  I feel, in general, that BIM has aided in the construction industry working together instead of as separate units; so it does not just benefit the systems within the building, but the industry itself.

BIM for Architects and Engineers - Group D - Week 3

Chapter 5 of the BIM handbook discusses the transition of the design process between past methods and new advancements in building information modeling.

This transition yields several benefits for both engineers and architects beginning with consistency. BIM design allows architects and engineers to work in a consistent format across all drawings and reports for the project. From this form of organization, communication between both parties is never broken or skewed which allows all parties involved to be on the same page. In addition, the benefit of BIM allows architects to provide enhanced visuals from 2D drawings and renderings to detailed 3D models in practice.  The models then can be subject to simulations and analyzed for more accurate cost savings. By using software, a cost savings analysis can be performed in a building model based on assemblies, recipes, or items and correlate them to a cost database like RSMeans.

            In Brian’s post, he discussed the former issues between architects and engineers and how architects refused to take responsibility for construction projects because their drawings were not exact designs and lacked explicit details that the contractor had to address on site. Brian also mentioned the fallout method due to these issues such as Design-Bid-Build and Design Build. He further went on to write how the addition BIM has restructured the bidding process with Integrated Project Delivery system. This system allows the streamline of documentation by vesting the designer in the completion of the project to benefit from the building like the contractor.

Source:

Chuck Eastman, Paul Teicholz, Rafael Sacks, Kathleen Liston; “Bim Handbook, a Guide to Building Information Modeling for Owners, Managers, Designers, Engineers, and Contractors” Second Edition, Chapter 5; Second Edition 2011

Comment on Brian Benson’s Post

I enjoyed reading your post. Like Ryan said, it proved to be a very accurate summary of the entire chapter. The first design challenge for BIM that you stated in the second paragraph where you described the definition of the design process and roles of the team members was an aspect that I overlooked in the chapter. I didn't think it was a major concern until I read your post.

 http://ae-510-ay13-14.blogspot.com/2014/01/bim-handbook-chapter-5-bim-for.html

Comment on Stephen Bartal's Post

Stephen, your summary of parametric modeling was very informative. The capability of modifying a few parameters to change all of the desired elements is significant time and cost saver. The incorporation of your own personal story regarding the Revit and AutoCAD was interesting to me. I hardly use Revit anymore, but the parametric modeling function makes it more appealing. I used to spend hours making tedious changes similar to your story, but now I see that there's finally a way to lessen the time required on making late changes to documents and projects.
 http://ae-510-ay13-14.blogspot.com/2014/01/group-bim-tools-and-parametric-modeling.html?showComment=1390325747876#c2480066411220141025

Comment on Melanie Wayne's Post

Did the chapter list the software used by these smaller firms and how expensive are these licenses? I found your discussion on 4D modeling very eye-opening. The incorporation of time in the models, I believe, is remarkable since it impacts coordination and project budgeting.
 http://ae-510-ay13-14.blogspot.com/2014/01/chapter-6-bim-for-contractors.html?showComment=1390326237824#c556888731269905540