Week 4 - BIM vs. Drafting (with a CAD Program) - Advantages and Disadvantages

BIM vs. Drafting (with a CAD Program) - Advantages and Disadvantages

As many companies merge towards incorporating BIM into most of their projects, they may wonder if using BIM has more advantages than disadvantages.  The easy answer to this question would be that BIM is much more advantageous due to its ability to perform parametric modeling and incorporate all of the different systems within a building at once.  For example, Dongyan Qi described in his blog post about BIM being able to provide a 3D walkthrough and renderings of all of the systems.  However, BIM does more than just this.  Unlike BIM, CAD is a 2D technology that outputs a collection of lines and text on a page. These lines have no inherent meaning, whether inside the computer or on the printed sheet. . . there is little to no correlation or intelligent connection among them.” (Dzambazova)  If two parallel lines are drawn in CAD, they say nothing about that wall other than it exists.  It does not give the materials that make it or any of the material properties.  BIM, on the other hand, is modeled so that “Each component and material understands its physical properties as well as how it will perform as a building system so we can get rich data out of the model regarding heating and cooling, most efficient building orientation, solar gains, etc.; we can test our building before it’s built” (Webster)  The objects are no longer modeled as just a set of lines that give the dimensions, they can be specified “in terms of its structural, acoustic, thermal or aesthetic performance. “ (Hamil)  Engineers can use this info, which can be updated if necessary, to determine things like how the combined insulation properties of external and internal walls affects the heating and cooling loads that will need to be provided by the HVAC in the building. 

As convenient as it is to be able to monitor and produce models that can provide these properties, it can have some drawbacks as well.  For example, CAD can be seen as being advantageous because it provides “a set of instructions for the intended means of constructing the building. Exact means in this method are hashed out during shop drawings, coordination meetings and often in the field after construction has begun.” (Webster) This allows engineers using a CAD system to speed up the process of erecting a structure.  Many owners of the structure being designed would love to start the construction process as soon as possible, especially if they know that decisions can still be successfully made regarding the design after they have broken ground.  Also, there are many custom made materials and parts that are not included in the libraries of BIM software of objects to be modeled.  Matt Morimoto mentioned in his blog post about conduit elbows sometimes not being able to be connected due to sizing issues.  Although BIM software such as Revit allows the creation of families to model and place new 3D objects, it is sometimes only necessary, and therefore easier, to just provide a simple 2D model that can be easily created in a CAD system.  

Resources:

Dave Webster. "Keys to a Successful BIM Implementation: BIM vs. CAD: Really…What’s the Difference?" MasterGraphics Weblog RSS. N.p., 26 Oct. 2011. Web. 28 Jan. 2014. <http://www.mastergraphics.com/wordpress/2011/keys-to-a-successful-bim-implementation-bim-vs-cad-reallywhats-the-difference/>.

Dzambazova, Tatjana, Eddy Krygiel, and Greg Demchak. "Understanding BIM." Introducing Revit Architecture 2010: BIM for Beginners. Indianapolis, IN: Wiley Pub., 2009. N. pag. Safari. Web. 28 Jan. 2014. <http://my.safaribooksonline.com/book/cad/9780470473559/understanding-bim/how_bim_is_different_from_cad>.

Stephen Hamil. "Isn't BIM Just 3D CAD?" Nbs, Aug. 2011. Web. 28 Jan. 2014. <http://www.thenbs.com/topics/bim/articles/isntBimJust3Dcad.asp>.

Week 4 Blog Post - Edward Bruder

The topic I choose is:

• BIM makes the Engineer's Work Easier vs It makes the Engineer's work Harder

     I choose this topic mainly because I personally and strongly believe that BIM will make engineers work easier rather than harder. Not only is it easier, it is also, in my opinion, a lot more fun to work with. BIM is much more advanced then CAD or hand drafting thus leading it to improve building in the future as well.

     BIM can be used many different ways, such as; 2D, 3D, and even 4D. At its most sophisticated level, BIM combines all the documents, data, and software packages used during design, construction, and, ultimately, operation and management into a single electronic source. [1] This will ultimately replace all types of engineering into one system. This system is so powerful that I only know a percentage of what the program can do.

     The performance from BIM will ultimately make work easier for engineers. This is because BIM can do multiple operations to help create a final design. Not only can it help find errors it can also help fix them. This will save time and ultimately help engineers create more efficient and creative designs. BIM is a platform that can provide a comprehensive and interactive assembly of the components in a building to create a new type of energy model. As more information is added to BIM for each individual part of the building, BIM becomes increasingly closer to matching the real world building itself. [3]Designs that would never be possible if not for BIM are being created every day. It is truly amazing.

     BIM’s 3D modeling is also impeccable comparatively to some other programs. You can actually see what the project would look like before it is even built. This is a huge advantage to the industry in the sense that you can change the way the building looks and see what the cost difference will be. All of which makes an engineer’s job easier.

[2]

     As seen from the graph the BIM work flow only has an increase in cost and effort in the detailed design phase of a project. This is a huge advantage over the other phases in a project.

In conclusion I believe that BIM works seamlessly with engineers to create amazing projects. BIM will definitely make work for engineers easier and will further the human advancement with in building projects.

References:

[1] Fortner, Brian.  Special Report: Are You Ready For BIM.  Civil Engineering The Online                 Magazine.  May 2008.

[2] Strafaci, Adam. What Does BIM Mean for Civil Engineers. CE News. October 2008.                       http://www.cenews.com/magazine-article----                                                                                     what_does_bim_mean_for_civil_engineers_-6098.html

[3] Alcorn, Terence. "How BIM Can Improve Building Efficiency." Facilitiesnet. n. page. Print.               <http://www.facilitiesnet.com/green/article/How-BIM-Can-Improve-Building-Efficiency--14297

Comment on Other Blog Post:
To Matt Morimoto:

Matt: I liked how you talked about both the positive and negatives of the BIM system but I'm not sure which side you chose. I do understand the pitfalls of using a BIM program but when I looked at the question I thought of BIM in a personal use frame of mind. What I mean by that is I understand that moving from CAD to BIM is frustrating but I believe that once BIM takes over and it more widely taught in schools it will become like a second language. But very nice post, very well written and insightful.

Group A: BIM vs. Drafting (Advantages and Disadvantages)

BIM is a system through which a 3D model can be used to produce both 3D and 2D drawings. In addition to drawing, BIM is based on databases from which information on the type of object being drawn can be extracted. This database can also be used to come up with schedules.

One of the advantages of BIM modelling, I learnt more about last week. This is parametric modeling. BIM systems have the ability to change a portion of the structure and other parts of the model will change in accordance. For example, if the size of a wall has to change, the slab thickness and sizes of the other walls will change to accommodate for the new wall dimensions. CAD programs such as Autocad do not have this ability. The designer, after changing the dimensions of one wall, would have to go through all the objects that are affected by this change and alter them accordingly.

Figure 1 shows that that with BIM programs, most of the work is concentrated in the design process while with CAD drafting, when changes had to be made, since it takes longer to make these changes, the most amount of work would be concentrated in the construction documentation phase of the project. “Civil engineers typically design for code compliance, not for constructability. But incorrect interpretations about design intent made in the field because of ambiguous documentation can lead to delayed schedules, change orders, and RFIs after construction begins.” [2]

Another advantage of BIM programs is that through the database, a designer is able to determine how many cubic feet of concrete are being used for the walls. This is not something that was previously available in CAD programs.

BIM has become so well known that even clients have begun to understand its effect on the design process. As a result, clients know that changes can easily be made. Making changes late in the process can lead on an increase in design and construction costs.

Another disadvantage is that a large amount of file space is required. This means that there has to be a change in the computer hardware as a result of the change in the software.

Comments
Mike: It was interesting reading about how BIM will actually improve buildings not just improving the ease of their design. I had not thought about how this would change especially for the HVAC system; improving the thermal comfort of occupants. I don't know Revit that well but I believe it is able to determine how energy efficient a room is and takes into consideration not just the HVAC system but other ways in which heat/energy can be released and absorbed. BIM will help reduce the amount of energy that is wasted in the building.

Steve: You're definitely right in saying that BIM will lead engineers to be more creative with their models due to the reduction in the amount of time spent making changes. As Mike also discussed, HVAC is a component of the model that may be most affected due to the improvement in the estimation of the energy efficiency of the room. I find the urban planning option really interesting since it would be helpful with my senior design project.

Matt: I found it interesting that you talked about how engineers have a hard time adapting to Revit. I believe this is one of the fears of companies that inhibit them to switch over. However, the ability of BIM to coordinate between different disciplines hugely outweighs how long it would take for engineers to get used to the program. 

References

1. Lister, David. "What Is BIM?" Precise Drafting, Inc. N.p., n.d. Web. <http://www.precisedraftinginc.com/bim.html>.

2. Strafaci, Adam. "What Does BIM Mean for Civil Engineers?" CE News. ZweigWhite, n.d. Web. <http://www.cenews.com/magazine-article----what_does_bim_mean_for_civil_engineers_-6098.html>.

BIM vs.CAD Drafting

Building information modeling is revolutionizing how drafting is performed in practice. The CAD programming software is slowly becoming obsolete as BIM becomes more inexpensive and more widely used in practice. The movement from 2D drafting with 3D elements to complete 3D, heavily detailed models is changing how engineers operate in regards to design. There are differences between the two that garner special note, since each has pros and cons to their usage.

Programming using CAD software enables a user to design a part or building with ease, however this quality is also its biggest drawback.  Less experienced engineers are able to create designs that appear to be ideal and suited for manufacturing, but in actuality, they cannot. CAD allows a user to “simply mate two parts” (Webster) that touch and are flush with one another. In the real world, those two components need to be bonded by means of welding, adhesives or fasteners. The use of CAD leaves a lot of discrepancies, due to lack of details that are addressed by the contractor in the field. These "on the fly" changes, in turn cause  a waste in productivity, time and money.  In contrast, CAD today enables designers to create free-flowing shapes in addition to contours and blended angles that add a sense of creativity and individuality. The advancements in CAD over the past 20 years have given features like documentation tracking for project files.

The biggest asset that BIM has is the ability to test your building before it is even built. Its virtual construction allows for accurate testing for heating and cooling, solar gains, orientation efficiency and much more. In addition, BIM design is much more exact than CAD drafting. The 3D model allows for much better analysis of building systems and quantifiable data. The negative impacts of BIM include a change in work ethic or workflow and a required internal and external education about BIM. The education is needed for a user to maximize the efficiency and use of BIM. These cons affect how a company sells its services and requires the company or firm to allocate their project budgets differently. 

From reading Esther's blog post, BIM's reliance on databases allows it to create various schedules with ease. In addition, the ability of parametric modeling which modifies all common elements when a parameter of that element is changed. After reading Michael's blog, trend within the building can be monitored using BIM and the building can adapt to make changes to the indoor environment to prevent energy waste.

Sources:

1. Webster, Dave. "Keys to a Successful BIM Implementation: BIM vs. CAD: Really…What’s the Difference?" MasterGraphics Weblog RSS. AEC Industry, 26 Oct. 2011. Web. 23 Jan. 2014.

2. Thilmany, Jean. "Pros and Cons of CAD." ASME. ASME, Mar. 2011. Web. 23 Jan. 2014.

3. "NEWS." Understanding BIM vs. CAD: NEI Electic in Minnestoa and Wisconsin. N.p., n.d. Web. 23 Jan. 2014.

Comments:
Esther's blog: 
I liked how you added that diagram to support your findings. The BIM workflow line is very interesting to me because of how effective it is in regards to all the project phases. In addition, I didn't know that BIM databases provide information such as the cubic feet of concrete for walls. Information like that is extremely beneficial for material costs.

http://ae-510-ay13-14.blogspot.com/2014/01/group-bim-vs-drafting-advantages-and.html?showComment=1390926036605#c4504943573435964367

Melanie's blog: 
f there isn't a BIM software standard, what are the most popular BIM software on the market today? Also, does the learning curve time differ for each BIM software?

http://ae-510-ay13-14.blogspot.com/2014/01/ways-that-bim-makes-engineers-work.html?showComment=1390926737346#c6006029837994680049
Michael's blog
I agree with you on how BIM can increase energy efficiency within a building by addressing thermal comfort better than typical HVAC systems today. The data gathered from the building in regards to solar heat gains, open windows, low activity, etc. all provide a means to reduce energy consumption and costs. I also agree about the trends of occupancy rate and other trends that will eventually need to be monitored to prevent wasted energy in order to effectively condition the indoor environment, when inhabited.

http://ae-510-ay13-14.blogspot.com/2014/01/week-4-bim-will-improve-buildings.html?showComment=1390927655770#c8298848065309071676