The BIM Matrix (part 2)

In the previous example, I have shown how to get the quantities for concrete, not including labor or other cost associated with the quantities.

In the pre-design stage, it is important to estimate all the "unknowns" or "unknown variables" as close as possible, therefore the IPD process is very useful. The MacLeamy Curve shows how IPD could potentially help your project finish on time and on budget.

These unknown variables can be calculated simply by using previously bid jobs, and substituting those variables into today's conditions. But the more unknown variables exist, the more equations are required to solve the problem. Here is a simple problem with 3 unknown factors (X, Y, Z), where any of these variables can be any real number, and 3 equations required to solve the problem.

$X + $Y = $Z

$X + $Y = $Z

$X + $Y = $Z

Very simple, three unknowns, three equations.

Well, as shown in part 1, knowing some properties or information about the equation, such as cost of materials (X variable) can help us estimate the other two variables (Y and Z) and narrow down the cost. This example can be used as:

1. equation 1 is simply the cost of material + labor = estimated cost ( labor used from source A)
2. equation 2 is the cost of material + labor = estimated cost (labor rates from source B)
3. equation 3 is the cost of material + labor = estimated cost (labor rates from source C)

As the project keeps growing through other design phases, these unknown factors will keep growing and growing, going from three unknown factors with three equations, to 20 unknown factors, therefore requiring 20 equations. Estimating all unknown factors can be challenging, but can be manageable using the matrix. Below is an example of the cost factor matrix (i.e. for concrete) and all the properties to the material "concrete" can be adjusted or accounted for using the simple matrix. Properties can be added or deleted for different type of material, therefore increasing or decreasing the number of unknown factors.

The BIM Matrix (part 1)

Today I want to show an example of detailing. In VD&C, too much detailing is as useless as too little detailing. In the preliminary design phase when trying to figure out quantities, a good baseline is essential to good planing.

Now, I would like to show an example of the theory.

In the example shown below, I have modeled a space, 120 ft x 100 ft, with 3 levels and a roof.

The materials used:

• level 1 has a 12" generic concrete pad, 12000 CF
• levels 2 and 3 have a 3" LW concrete on 2" metal deck, 5000 CF per floor

The concrete quantities yield a total volumeof 22,000 CF.

The area of the slab yields a total volume of 60,000 SF, which includes the area of the concrete slab and the area of the metal decking for the 2nd and 3rd floors.

As seen in the schedule below, all the different parameters are shown (i.e. area, family and type, etc) and the total quantities of the area. What is not indicated in the schedule is a description of the slab for the 2nd and 3rd levels.

How do we make this schedule more essential or efficient? Well, let's modify the model with the following:

• add a slab edge to all floors, which will change our concrete quantities,
• see how the slab edge will change our cost for the concrete volumes,
• and customize the schedule for export to excel and make it more effective.

Let us estimate that 4000 psi concrete is at about $70.00 per cubic yard.

Because Revit families are dependable on the same type, giving our LW concrete the unit cost will change all the elements of type LW concrete. Instead, we will create calculated values and name it TOTAL COST per CY. Revit has calculated a total dollar amount of 57037 so far for our material, that is not including labor or other associated cost.

So, if you are asking yourself "how is this a BIM Matrix", well read part 2.

Some information on BIM

Some information on BIM that I have been researching lately.

More to come...

http://www.cfm.va.gov/til/bim/BIMGuide/lifecycle.htm

http://www.gsa.gov/portal/category/21062

http://www.buildingsmartalliance.org/

http://www.wbdg.org/index.php

http://www.csinet.org/Main-Menu-Category/Communities-2109-14280/Practice-Group/BIM.aspx

BIM and the Law

Ever wondered who owns or is responsible for all the information gathered for a BIM project? Or, ever wondered what party is expected to perform a certain task? Well, these questions are hard to answer in the Integrated Project Delivery (IPD) practice because all vital information is being shared among the project parties.

I will not go too much into the detail of this subject, so below is all the information you need in order to understand the basics of construction documents such as:

• Consensusdoc 301
• AIA E202
• BIM execution plans

http://www.agc.org/galleries/contracts/ConsensusDOCS%20301%20BIM%20Addendum%20Article.pdf

Also, what is the difference between the Consensusdoc 301 and the AIA E202 document?

http://www.woodsaitken.com/Presentations/Legal%20Aspects%20of%20Intelligent%20Estimating%20and%20BIM.pdf

Energy Modeling

Since energy modeling is a big part of BIM, I have decided to get my LEED GA accreditation. I have always had an interest in building energy analysis, and a combination between Revit, Ecotect, and Green Building Studios just lets me visualize a building's energy performance.

A few steps to know:

gbXML vs DXF

gbXML (Green Building Extensible Markup Language) is good for:

• exports the model as model analysis data, meaning all rooms from Revit are imported as spaces and all material names from Revit are imported
• whole building energy use and cost
• water use and cost
• carbon emissions
• heating and cooling load analysis
• LCA
• HVAC equipment sizing
• lighting analysis
• and more

DXF (Drawing Exchange Format)

• exports the model in 3D geometry, meaning that the model is exported in layers, not material, i.e. exporting curtain walls in DXF will result in the curtain walls being a solid in Ecotect because the curtain wall is a solid layer
• spaces were not exported in DXF and should be defined under the zones tab
• before importing the model, make sure to specify the scale by multiplying by 25.4 to convert from SI units

Make sure that the rooms in the Revit model are properly enclosed, because any room that is not properly enclosed, Ecotect will analyse it as the outdoor space, giving you inaccurate energy analysis.

Loading different weather data from the web site:

http://www.youtube.com/watch?v=koLHunYPlto

Keep the model simple. DO NOT import details because Ecotect does not see details, it only recognizes spaces and openings.

Are You Ready for BIM

On today's topic, I discuss some aspects of adopting BIM or Virtual Design and Construction (VDC). If you are a contractor, architect or engineer, here are some suggestions from my personal studies and experience to see what it takes to get the "BIM Department" in your firm going.

First and foremost:

..."BIM is great, but it's not for everybody"...

The reason is simple; different circumstances require different procedures. I will not go too deep in the discussion, but from the report published by McGraw Hill Construction in 2009 called The Business Value of BIM:Getting Building Information Modeling to the Bottom Line; the numbers show the following:

1. Contractors see the highest Return on Investment (ROI) in BIM with 71% reporting positive results, followed by
2. Owners, 70% reporting with positive results
3. Architects, 58% reporting with positive results, and
4. Engineers, 48% reporting with positive results.

*see sources below*

As a firm, do you have the resources for:

• hardware and BIM software
• BIM training
• marketing/advertising your BIM capabilities
• upgrades (depending on the project)

Productivity and ROI:

The diagram shows an immediate dip in productivity as users get familiar with the new software and collaboration process. However, productivity should level out with time, depending on the firm's progress to implement and understand BIM.
Your ROI depends on how long it takes your firm to adopt BIM practices and at what cost.
A (cost of hardware and software), B (Monthly labor cost), C (training time in months), D (% of productivity loss during training), E (% of productivity gain after training).

This would summarize my findings on adopting BIM and VDC practices.
I think that this is a good start for anybody to understand what the pros and cons are. Also, I would just start out by trying BIM software and see how users adjust to it. Depending on those results, I would suggest whether BIM is right for you.

More Information and Sources used:

http://www.bim.construction.com/research/

BIM Project Tracking

This discussion summarises BIM 4D and 5D modeling and how you can get the most of it. Summarized in this blog is the use of some 5D software that are available as a trial version, assuming you have Revit, Navisworks, Autodesk QTO and Microsoft Project.
So if you are like me and want to know more about 4D and 5D modeling without spending a lot of money on software licences, but rather get the full use of free trial versions, please read on.

Quick Introduction
The great thing about Virtual Design and Construction (VDC) is that all aspects of the project (modeling, scheduling, estimating, management, etc.) can be fully utilized prior to the construction phase. Actually, VDC can be fully utilized months or even years before the bidding stages. But in order to successfully implement the full use of BIM software, we need to understand the importance of each task, such as 3D, 4D and 5D modeling. Below is a link to the top ten reasons why 5D modeling is important and crucial to a project's life.
http://www.vicosoftware.com/0/blogs/virtual-construction-inside-out/tabid/84142/bid/11632/The-Top-10-Reasons-to-Do-5D-BIM.aspx?source=Blog_Email_[The+Top+10+Reasons+t]

My Experience
For the past six months, I have been trying to fully implement 4D and 5D modeling. There is great software available as a trial version, and I strongly recommend taking advantage of those.

One of the great software to use, that combines 4D and 5D modeling, would be ViCo. (office, estimator and 5D presenter). ViCo has free trial offers on their software, but not all of their software have BIM-neutral platforms, meaning that not all software support Revti applications.
ViCo Office supports a BIM-neutral platform, and you can import models from most BIM application software; but they do not offer a free trail version to ViCo Office.
More information can be found at
http://www.vicosoftware.com/Virtual-Construction-Management/tabid/46250/Default.aspx

There are other ways to fully implement 4D and 5D modeling. I have been mainly working with Autodesk products, since I have a student licence on Revit and Navisworks, and getting a great analysis on project cost and management. A few extra steps are necessary to obtaining similar results as in ViCo Office, but these extra steps just made me understand the concept behind 4D and 5D modeling. Below is my schematic and how I have learned to appreciate 4D and 5D modeling.

Again, this is the schematic on how I have been utilizing 4D and 5D modeling. The main difference between my technique and that, for example, of ViCo Office is that theirs is a bit more user friendly, meaning that there is less effort in importing, exporting and linking files. Also, my technique does not allow to view an animated version of project tracking, like Earned Value Analysis.

BIM Execution Plans

Lately, I have been interested in BIM execution plans and protocols. Besides viewing a great info session on Autodesk University, I have also been looking at previous execution plans, such as the AIA E202, Consensusdocs 301, and the Penn State Execution guidelines and templates.
I have to say that Penn State's execution plan is a little bit more detail oriented than the AIA E202 document, but in general it is good to understand all of the documents.
Here are some links to all documents:

http://www.engr.psu.edu/ae/cic/BIMEx/
http://www.pat.ca/files/pdfs/AIA_091708_E202-2008_eSample_Blank.pdf

In the AIA E202 execution plan, the Level of Development (LOD) is characterized in 5 different levels:

1. LOD 100 - Overall building massing indicative of area, height, volume, location and orientation may be modeled in three dimensions or represented by other data.
2. LOD 200 - Model Elements are modeled as generalized systems or assemblies with approximate quantities, size, shape, location and orientation. Non-Geometric information may also be attached to Model Elements.
3. LOD 300 - Model Elements are modeled as specific assemblies accurate in terms of quantities, size, shape, location and orientation. Non-Geometric information may also be attached to Model Elements.
4. LOD 400 - Model Elements are modeled as specific assemblies that are accurate in terms of size, shape, location, quantity and orientation with complete fabrication, assembly and detail information. Non-Geometric information may also be attached to Model Elements.
5. LOD 500 - Model Elements are modeled as constructed assemblies actual and accurate in terms of size, shape, location, quantity, and orientation. Non-Geometric information may also be attached to Model Elements.

This video illustrates LOD 100 - 500 form the perspective view.

Analyze your Models' Visibility quickly

Hello,
welcome to today's blog on how to analyze your model's visibility. These tips reveal on how to import a Google Sketchup mass into Revit Architecture, and export the model to Ecotect. Firs off, you will need to have Google Sketchup Pro, because this version allows the user to export any mass obtained in the Google Sketchup warehouse as a DWG file. When importing a DWG file from Sketchup, save it as a family in Revit and uploaded that family into your project. From here on, you can either continue to model the shell of your building in revit, or model the building in Ecotect as various zones (which I would not recommend because it is easier to model in Revit). I also would recommend, for this exercise, to export the Revit file as a DXF format to Ecotect. Also, when importing the file into Ecotect, import it as a 3D CAD Geometry option.Make sure to check the Auto Merge Triangles box. This will clear up the imported DXF file and make it easier to work with. Also, check the scale factor; the default setting for Ecotect in in SI units.

Here is the uploaded example. It is very easy to upload any site into Revit or Ecotect. All you need is Google Sketchup Pro and understand what formats to use (DXF, DWG, etc). This example illustrates a downtown area with the model of interest and a visibility analysis being performed.
Fore more information on how to export and how to generate a quick surrounding to your model, please leave me a comment and I will be glad to help.
Enjoy