Chapter 2 Building Information Modeling

Building Information Modeling (BIM) is the latest buzz in architectural design and drafting. Is BIM a revolution or just the way the industry works these days? In this chapter, you will be encouraged to contemplate and challenge the popular assumptions and standard definition of BIM.

By doing so, you should realize that integrating the benefits of BIM into your workflow is easier and cheaper than you ever thought.

Wh AT iS B i M?

“Building Information Modeling (BIM) is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle; defined as existing from earliest conception to demolition.” (National BIM Standard--United States) A building information model (BIM) is an intelligent model that integrates design, visualization, simulation, and collaboration into one process. The model is a physical representation, but it can also be informative. The model not only shows a client what a building will look like, but it also gives the client and designer a better understanding of how the building will function. A BIM is essentially a shared, digital building prototype that helps everyone on the design team make better decisions.

Stages and Uses

A building information model is intended to be used during every phase of the design process, and by every member on the team.

Architects typically create the main model and then share it with consultants who use the BIM to ensure that their trades don’t interfere with the building’s function or other trades. For instance, a duct physically can’t run through a beam. It is better to catch issues like this on the computer rather than in the field. This BIM feature is commonly referred to as clash detection.

Building owners and facility managers can also use the BIM after the building is complete. For example, a BIM could help them track down the source of a stained ceiling by locating plumbing lines or by indicating possible weaknesses in the roof membrane.

TIP in reality, most building owners and facility managers won’t use the building information model to solve problems—but they could. if they were to use a program, however, they’d find that the SketchUp viewer is free and very approachable.

Features

BIM is a concept not a software program. However, there are software programs that use the BIM concept to execute the design process. There is no official BIM features list, but here are a few popular features that most people expect to find in a BIM program:

☑ 3D modeling

☑ Model life-cycle use with the building, from predesign to demolition

☑ Interoperability with consultants and their CAD platforms

☑ Dynamic links between the 3D model and the construction documents. (When a change is made in a plan, that change is reflected in all other drawings, sections, elevations, and reflected ceiling plans.)

☑ Photorealistic rendering and raytracing

☑ Parametric modeling, both input and output

☑ Clash detection

☑ Energy analysis

☑ Cost analysis

☑ 4D construction phasing and schedule management

Ske T chU P A n D lAyoUT AS B i M

Coming as a surprise to most, SketchUp and LayOut contain many of the most popular BIM software features. With the workflow presented in this book, SketchUp and LayOut pull the best features from each of the most popular drafting platforms (2D CAD and 3D BIM). Using this workflow, you can incorporate BIM’s fundamental features into your projects. This section outlines what makes SketchUp and LayOut such a powerful design and documentation tool and explains why it is a unique design and documentation method.

Advantages

Some of the advantages of using SketchUp and LayOut as a design and documentation method are listed here:

☑ SketchUp is a surface modeler, which means that all objects created in SketchUp are composed of lines and surfaces. The process of drawing lines in SketchUp is very similar to the familiar process used to draw lines in 2D CAD. SketchUp could be described as a 2D CAD program that operates in a 3D environment.

☑ When you build a 3D model in SketchUp using The SketchUp Workflow for Architecture, you are simultaneously creating the construction documents. All 2D plans, sections, and elevations are dynamically linked to the 3D model. SketchUp allows you to think and design in 3D, which is the way your brain is wired to work. This is in sharp contrast to using other popular BIM software where you draft the construction documents, which in turn creates the 3D model. In SketchUp, you think and design in 3D; the presentation and construction documents are products of the design process. (See Figure 2.1 and Figure 2.2.)

☑ The lack of some features in SketchUp is a blessing in disguise. Because the rules for modeling and organizing are simple, there are fewer questions for the program to ask and, therefore, fewer questions for you to answer. The simplicity of SketchUp and LayOut lets you create and organize the model quickly, without interruptions. For example, to add a wall in some BIM software packages, you would have to assign several properties, such as height, thickness, material, color, and insulation. To add a wall in SketchUp, you simply draw a rectangle and pull it up—no questions asked. (In Figure 2.3 through Figure 2.5, the drafting and modeling were completed using SketchUp Pro, LayOut, and The SketchUp Workflow for Architecture.)

☑ SketchUp offers real-time rendering, which provides infinitely better information so you can make better design decisions than you can with other software. In SketchUp, a house looks like a house, siding looks like siding, and concrete looks like concrete. In 2D CAD, a house looks like a flat collection of cyan and magenta lines. The graphical representations of most textures leave disconnects between the drawings and real-world applications of the materials. The better the 3D information is that you have during the design process, the better your design decisions will be. Figure 2.6 shows the same project in 2D CAD and in SketchUp.

Disadvantages

Some of the disadvantages of using SketchUp and LayOut as a design and documentation method include:

☑ SketchUp lacks parametric modeling features. Dynamic components can be used to compensate for some of this, but they are fairly difficult to master. Ultimately, parametric modeling attributes can be exported and viewed in spreadsheets as reports; however, changing the spreadsheet will not be reflected in the model.

☑ Scheduling is done the old-fashioned way. The door and window tags are not connected to the door and window schedules. The tags and schedules must be coordinated manually.

☑ Sheets are coordinated the old-fashioned way as well. There is no information exchange between sheets, drawings, tags, and callouts. The drawings must be coordinated manually.

☑ LayOut dimensions do not update automatically when changes are made in SketchUp. If you move a wall in SketchUp, you will need to go back and correct the dimensions in any drawings that display that wall.

☑ Entities do not attach to each other. For instance, windows and doors do not attach to walls. So, if you move the wall, you will also need to move the doors and windows separately.

f illing in T he B i M Bl A nk S

You can use plugins to extend SketchUp’s BIM features. Third parties are creating plugins that expand the SketchUp universe and provide features that fill the BIM voids. Although the plugins listed in this section are not officially endorsed by or included in The SketchUp Workflow for Architecture, they provide a great place to begin your search to expand BIM capabilities.

Cost Analysis

☑ BimUp: www.bimup.co.uk/

☑ SpaceDesign: www.renderplus.com/wk/SpaceDesign_Features_w.htm

Energy Analysis

☑ EnergyPlus: http://apps1.eere.energy.gov/buildings/energyplus/energyplus_about.cfm

☑ IES V-Ware: www.iesve.com/Software/VE-Ware

☑ NREL OpenStudio: http://openstudio.nrel.gov/

HVAC

☑ 3Skeng: www.3skeng.com/en/index.htm

Parametric Modeling

☑ SketchUp BIM: www.sketchupbim.com/

☑ Instant Roof: http://valiarchitects.com/sketchup_scripts/instant-roof

☑ Instant Wall: http://valiarchitects.com/subscription_scripts/instant-wall

☑ Dynamic Components: www.sketchup.com/intl/en/product/dcs.html

☑ Build Edge: www.buildedge.com/

4D Timeline

☑ SuperPlan: www.superplan.info/index.html

Photorealistic Rendering and Raytracing

☑ Twilight Render: http://twilightrender.com/

☑ Shaderlight: www.artvps.com

☑ Podium: http://suplugins.com/

In Figure 2.7 and Figure 2.8, the drafting and modeling were completed using SketchUp Pro, LayOut, and The SketchUp Workflow for Architecture.

Chapter 2: Building Information Modeling

The Ske T chU P oUT look

For a few good years, Google owned SketchUp and supported it. Among other features, Google SketchUp introduced styles, the Follow Me tool, MatchPhoto, integration with Google Maps and Google Earth, and a huge leap forward with LayOut. The Google years were exciting at first, but after SketchUp 7 Google seemed to lose interest in the project and deprioritized it. Why would such a cool company do this to such a cool program? Perhaps it was because lighter cloud programs such as Google Building Maker can create 3D models for Google Earth, which was one of the original reasons Google purchased SketchUp. Another possibility is that taking on the architectural drafting industry juggernauts didn’t fit into Google’s mission statement, which is to organize the world’s information and make it universally accessible and useful. Either way, SketchUp was put on the back burner for several years during a period of minimal releases and minimal new features. Nobody likes a breakup, but it was time for SketchUp to tell Google, “It’s not me, it’s you.”

Google handled the breakup with maturity and sensitivity to the loyal SketchUp community by finding a buyer who really appreciated the product. Trimble, the new owners, might not have the allure and mystique Google has, but they do have some radical hardware.

Trimble creates GPS devices for automating farm equipment and efficiently fertilizing crops. They build handheld devices for construction management. Interestingly enough, Trimble creates 3D laser scanners. These high-tech machines can be placed in a room and within minutes they can generate an accurate as-built 3D model of the space. Yet another intriguing product that Trimble owns is Tekla, a BIM program aimed toward engineering. Now, with the purchase of SketchUp, they possess a wildly popular 3D platform that architects embrace. SketchUp may have been close to extinction, but now its future looks great.

c h APT er Poin TS

☑ Building Information Modeling is a loose concept open to interpretation.

☑ BIM is not a software program; it is a concept used by design and documentation software programs.

☑ There is no absolute set of features that defines BIM software.

☑ SketchUp is not marketed as BIM software, but it does offer several popular BIM features.

☑ Plugins can be used to fill in the BIM blanks.

☑ Most facilities managers won’t touch BIM. However, if they do, they would be likely to use SketchUp.

☑ Google sold SketchUp to Trimble instead of a huge AEC software company with the reputation for squashing competitors with buyouts.