s6-2 bim for construction

8/7/2019 S6-2 BIM for Construction

1/13

Navisworks, Revit, QTO, MaxBIM for Construction

Scott D Davis

S6-2

Course Summary:

In this class, we will first take a look at existing industry challenges and trends in the constructionindustry. Then the discussion will focus on Building Information Modeling (BIM) and what it means forcontractors and general contractors. Next, we will discuss the value of BIM for construction and why it'simportant to your business. After covering some customer success stories and hearing how contractors areaccomplishing more with BIM, we will conclude with how to get started in BIM for Construction, anddemonstrate the Autodesk software solutions for you.

Instructor:Scott D. Davis is an AEC Technical Specialist with Autodesk, Inc., and specializes in Revit Architecture andbuilding information modeling (BIM). Since joining Autodesk in March 2007, he has been active in promoting

BIM around the country at events including the AIA Convention and Green Build International Conference andExpo. He has taught classes on BIM and Autodesk Revit at Autodesk University and at AUGI CAD Camps,and was the founder of the Revit Users Group Inland Empire. Prior to joining Autodesk, Scott was a ProjectManager and the Technology Coordinator at WLC Architects, Inc, in Rancho Cucamonga, California. At WLC,Scott was responsible for bringing BIM to the firm, first discovering Revit in April of 2000. He was responsiblefor the firm-wide implementation of Revit for over 100 users across 3 offices. Scotts BIM portfolio includes theChild Development Center at Long Beach City College and the Silverado Ninth Grade Campus for VictorValley Union High School District.

www.uscad.com www.uscadbim.com


2/13

U.S. CAD


Copyright U.S. CAD: BIM/CAD Camp 2010

2

AUTODESK

REVIT ARCHITECTURE

AUTODESK

REVIT MEPAUTODESK

REVIT STRUCTURE

AUTOCAD

CIVIL 3D

AUTODESKQUANTITY TAKEOFF

AUTODESK

3DS MAX DESIGN

AUTODESK

NAVISWORKS MANAGE

The Autodesk portfolio offers a comprehensive set of tools toaddress the challenges faced by todays Construction industry.

Reap the rewards of more accurate estimations created in lesstime and comprehensive construction analysis that lead to bettercoordinated, and smoother running construction projects.

Use Revit MEP and/or Revit Architecture and/or RevitStructure to develop detailed models for accurateestimation and in depth construction analysis.

Use Quantity Takeoff for early bid quantification of 2Ddesigns, and full model takeoff as a result of the BuildingInformation Modeling process.

Use Navisworks software products to analyze andsimulate the construction model while the projectremains digital.

Leverage the BuildingInformation Modelingprocess to accuratelyestimate, spatiallycoordinate, and simulateconstruction projects, todifferentiate your businessfrom the competition andensure you win new

business.


3/13

U.S. CAD



3

LEVERAGING THE POWER OF BIM

These are challenging times for the construction industry. With fewer construction starts due toprojects being cancelled or put on hold, the playing field is a lot more competitive. Construction firmsare a looking for ways to differentiate themselves and to do more with less fewer resources, lowerfees, and smaller budgets.

New business can be won by demonstrating competence and inspiring confidence throughconceptual modeling, visualization, and thorough initial estimating, while assuring yourself that youcan build the project at the bid submitted.

Autodesk tools can be used to create the conceptual building information model (BIM) andcommunicate the design intent, while inherently providing the data for early estimating.

INITIAL 2D TAKEOFF

Although a number of architects are starting to provide building information models, cost estimatorsare often required to perform takeoffs based on 2D design data, or high quality digital images fromthe design. For this reason, Autodesk Quantity Takeoff has a full set of intuitive manual takeoff tools,enabling you to perform on screen takeoff of design data such as walls, doors and windows.

Even when there is no intelligence behind the files being used - that is, 2D files and images

containing lines and arcs with no concept of scale or the objects they represent with AutodeskQuantity Takeoff (QTO) you can manually measure an object of known dimensions and use this toset the scale of the project files. All linear and area takeoffs are then automatically calculated andrecorded in the correct scale.

So lets focus on some of the manual takeoff tools available to you. When quantifying the number ofdoors on a project for example, you need a means of marking each door as you count them if youhad all of your sheets printed out, then youd likely be using different colored pens and symbols toclassify each door type and keep track of the count as you work through the sheets. QTO offers thissame takeoff method in a digital format, allowing you to quickly count and track items within the sheetAgain colors and symbols can be chosen for each object type, and these are automatically tracked,so each count on the sheet directly corresponds to an item in the Takeoff palette. These can easily begrouped and organized exactly how you want them, and any mistakes can be quickly rectified bydragging and dropping an item from one group into another, with QTO re-assigning the relevantTakeoff symbol.


4/13

U.S. CAD



4

When quantifying walls for example, tools are available for you to perform linear takeoffs with a singleclick although these 2D sheets have no object intelligence, QTO can recognize individual lines, andas we setup the scale earlier merely clicking on a line representing a wall provides you with anaccurate length. The takeoff group can be renamed to identify the object type and if required,additional properties can be assigned, including details of the objects construction. For example, youmay wish to calculate the number of studs and gypsum boards required for each section of wall, andthe total number for the project all of which can be easily calculated from the takeoff.

When taking off areas such as flooring, QTO provides tools to quickly mark out and calculate the areaThis is particularly efficient when quantifying the area of non-uniform spaces, such as open plan officeareas and corridors. Again, colors can be used to identify different areas, along with standard hatch

patterns.

While carrying out the quantification, the Workbook is also being built out, providing another view ofthe building components. The workbook allows you to add initial cost information against each takeoffgroup, including material and labor costs, or flat fee subcontractor costs as and when theyreavailable. Reports can be generated directly from QTO, and quantities can be exported to MicrosoftExcel.

CREATING A DESIGN INTENT MODEL

While there are several ways to leverage 2D designs to inform the construction process, trendsindicate that more and more designers are creating 3D models and with good reason.

3D Models:

Dramatically speed up the quantification process that informs estimating.

Enable better coordination when aggregating designs across several disciplines for the purpose ofclash detection

Improve communication of design intent through visualization tools

Creating a 3D model isnt that difficult, especially when you have existing DWG data.

Well start by importing a number 2D DWGs into the model that was created using AutoCAD. Wellfocus on defining the floors of the building for the next couple of minutes. In this case, the DWG base


5/13

U.S. CAD



5

plans provide a vital input to the Building Information Modeling process. Revit understands the DWGline work and allows the architect to snap intelligent real world building components directly to the linework. This makes modeling a snap!

At this point during the modeling process, were working towards a lightweight model. As such, wewill only focus on the major design components, such as exterior walls, openings, windows, doors,floors, and roofs. The goal is to describe the key components. As we go through multiple iterationsof this model for the course of this demonstration, well continue to make updates - based on findingsthrough quantification, material assignment, clash detection, and phasing. Ultimate, this process willallow us to transition from this design intent model to a model that will ultimately inform every aspectof the construction process.

MODEL QUANTIFICATION AND ESTIMATION

With the availability of a Building Information Model, Autodesk Quantity Takeoff (QTO) enables you tospend even less time counting and measuring, and more time focusing on creating your estimate.

In this example well start by using a UniFormat catalog to organize the takeoff. Well also use a DWFfile exported directly from the Design Intent model. A DWF file exported from Revit can not onlycontain the 3D model, but also the associated 2D sheets.

Due to the intelligence inherent in the model through BIM, QTO can automatically search through thisinformation and takeoff the entire model at the click of a button. Furthermore, as the 2D sheets areassociated with the model, QTO cross-references these for all taken off items. The power of this isseen when reviewing the Takeoff palette, as each item may be presented in a number of views, thatis, the model view and each 2D sheet that contains the selected item.

An incredibly easy to use, drag and drop interface enables you to move the takeoff items into thecatalog structure youre using. And all the while, the Workbook continues to build up with information.For example, looking at these 4 7/8 Partition Walls, while the model takeoff identified and recordedeach instance of this wall type, QTO is also accumulating and presenting you with the total footage,something that would traditionally have taken hours or days to calculate, along with removing the risk

of human error.

All of this is possible due to modeling building components that know what they are not simply asolid object that represents a wall, for example, but an element that knows its a wall, knows its


6/13

U.S. CAD



6

dimensions, and how its constructed, and so on. This is the power of BIM, and how it takes QTO tothe next level.

But it doesnt end there. Autodesk have partnered with a number of estimating solutions such asSage Estimating, MC2, and RIB whose integration with QTO enable you to export your takeoff intothose estimating packages. Lets take a closer look at the QTO to Sage Estimating workflow, as anexample:

When integrating with Sage Estimating, QTO enables you to import a catalog of items andassemblies from Estimating. You can then associate elements from the model with the items andassemblies in Estimating. Once the associations are made, its a matter of one click to export thequantities and dimensions from QTO and create a new estimate in Estimating.

So lets start with the same TRAPELO_DESIGN_INTENT.dwf file, though rather than using theUniFormat catalog, well import a catalog from Sage Estimating. The integration plug-in providesaccess to an existing estimate file (*.pee) if you use template estimate files for example, or the entiredatabase (PEI.dat) from anywhere on the machine or network.

Having made your selection, you have the ability to filter your selection of assemblies and items. Sowhen importing a database as in this example, you have control over which items and assembliesyou wish to include. QTO remembers your selection and applies the same level of filtering the nexttime you open this database, saving you from repeating this operation each time.

As with UniFormat, the catalog is available from within the Takeoff palette, and the model structure is

seen in the Model palette. You can select a group of elements in the model and hide everything elseto make it easier to see what youre taking off.

Using the Takeoff to Item option, you can map the element type directly to a specific item or assemblywithin the catalog. QTO then takes that item off and assigns all 278 instances of the wall, in thisexample, directly to the corresponding catalog item. This provides a more methodical workflow asopposed to the one-click model takeoff and subsequent drag-and-drop catalog restructuring.

Having assigned the wall type to an assembly, you can then define how QTO should quantify thatitem, whether it should be a count, or quantified by volume, area, or in this case, linear. Youre alsopresented with additional Catalog Parameters values that are required to create an accurateestimate. These default variables and units auto-populate, based upon the selected assembly, and

you need to map these variables to the quantities or attributes from the wall object type (in thisexample). A Formula Editor is available to either select the relevant attribute/property, such as Lengthor Height. Alternatively, if an attribute doesnt exist the Formula Editor allows you to calculate a valuefrom other known attributes.


7/13

U.S. CAD



7

Now that these variables are mapped to the relevant model attributes, when you look at theproperties for each wall you can see the quantities associated with each dimension, for example thelinked Length and Height. When this wall is generated in the estimate, these are the values that willbe quantified in the assembly.

These quantities can be exported to Estimating. This is not an export / import integration when youexport from QTO it actually performs the takeoff and creates an estimate which can be opened andreviewed within Estimating.

The best way to review the estimate created by QTO is to use the Review Assemblies mode withinEstimating. You can see how each wall within the model has created a pass in the assembly takeoff,and further the specific quantities that populated the variable entries.

As you click through the different passes, you can see the Length and Height of each wall arepopulated with the specific quantities from the model.

Therefore, by using Autodesks Revit platform for BIM, object quantities (doors, windows, walls, etc.)and dimensions are stored within the model, which can be extracted using QTO for use withinEstimating. Simply drag and drop the model elements to the estimating database for a simple one-time integration setup. Once this mapping is completed, its stored within QTO for use on subsequentprojects. Exporting this data to Estimating provides a fast, accurate and automated process forcreating cost estimates.

THE BIDDING PROCESS

At the bidding stage, BIM can be used to set a baseline for the estimations, verifying the quantities forinitial estimates and validating the bid data received from subcontractors.

Autodesk tools - such as the Revit family of products and Civil 3D - can be used to develop theconceptual model of design intent, into a construction model. This stage of the modeling processadds the level of detail necessary to analyze the constructability of the project, including splittingcolumns into levels, and floor slabs into individual pours, for example.

Sharing the BIM with bidding subcontractors, in a CAD-neutral format (NWD or DWF for viewing in

Navisworks Freedom or Design Review), provides them with greater project understanding and betterinsight into the building design, which fosters collaboration and more accurate bid submittal.


8/13

U.S. CAD



8

Autodesk Quantity Takeoff can further be used to take measurements, areas and quantities from theconstruction model, allowing exact square footage of certain materials for example, to be sent out tosubcontractors to obtain accurate cost validation. This allows for continuous cost control to help staywithin the budget.

BIM MODEL AGGREGATION

Large construction projects can involve any number of stakeholders, from the owner, to the designteam, to the general contractor and specialist subcontractors. The design software being used can besimilarly diverse. Sharing models between stakeholders can therefore be of limited value without aseat of the authoring software, therefore often relying on 2D drawings as a common means for

communicating intent.

Navisworks replaces this outdated means of communication by allowing models from various designapplications to be integrated within the same scene. This intuitive environment allows all involved toshare a common project vision, making it easier to see how their part of the project fits within theoverall design. This aids understanding and fosters a better collaborative relationship betweenstakeholders.

The project seen here has been modeled in AutoCAD Civil 3D, Revit Architecture, Revit Structureand Revit MEP. As the project progresses and specialist trades develop their own constructiondocumentation - using whichever design application is appropriate to their industry and workflow -

Navisworks allows those designs to be combined with the overall project model. The complex modelscreated through the Building Information Modeling process can result in large file sizes. However,Navisworks innovative technology compresses these files for interactive visualization and smoothreal-time walk-through, so you can navigate, explore, and review large, complex 3D models onstandard PCs. Furthermore, you can realize the value of BIM projects without requiring seats of theauthoring design applications and the necessary skills to use such software. The integrated projectcan be distributed in the highly compressed and secure Navisworks NWD format, providing access tothe model and associated building information using the free viewer, Navisworks Freedom.

COORDINATION AND SCHEDULING

In construction, coordination and scheduling is the combination of logistical planning and continueddevelopment of the constructability model, all focused on understanding the relationship to the buildschedule.


9/13

U.S. CAD



9

With multiple disciplines and subcontractors working on a project, its important to coordinate theseduring the pre-construction phase, to minimize the risk caused by RFIs and change orders that occuron-site. Identifying issues and making changes to the designs is quicker, easier and more costeffective when compared to on-site changes. And when using Autodesk tools such as Revit, anychanges to address coordination issues are automatically propagated throughout the model andassociated views, maintaining an accurate representation of the project. Changes in the design filesare similarly reflected automatically in the Navisworks project file (*.NWF). Greater confidence in thecoordination of disciplines additionally allows for more off-site fabrication, which lead to further costsavings and an increase in quality.

Construction planners can leverage the BIM to simulate the project schedule. Autodesk tools such asNavisworks can integrate with complementary scheduling software, including Primavera, ASTA andMicrosoft Project. This allows planners to continue using the scheduling software theyre familiar with

and then tie that schedule information to the data rich model. The result is a 4D sequence of theschedule which allows you to visualize the construction process, providing the opportunity to play outwhat if? scenarios; present alternative construction methods; plan and visualize lay-down areas,material drops, and other logistics for the entire site; perform safety and risk reviews virtually beforethe build begins; and influence public outreach.

SPATIAL COORDINATION AND CLASH DETECTION

Building Information Modeling presents the opportunity to spatially coordinate all of the different

project disciplines. And although there may be additional overheads in creating these models, thebenefits of fully coordinated designs includes confidence that everything will fit together, allowing formore off-site fabrication and on-site installation; fewer on-site RFIs and resultant change orders,which leads to fewer project delays; and ultimately reduced risk. The Navisworks Clash Detectivefeature realizes this potential and demonstrates one of the real powers of BIM in construction.

Clash Detective works by looking for issues between specific groups of model objects, or disciplines.The idea being that you define a test looking for issues where you might expect to find them, basedon past experiences for example, and Navisworks will do the hard work of searching through thecomplete project model, identifying any issues. This is quicker and more accurate than the traditionalmanual method of looking over plotted drawings on light boxes.

As the model is rich with building information (created in the authoring design application), you canuse this data to define search sets, which identify groups of like construction components, such as allof the structural components on the first floor, for example. Basing clash tests on these sets means


10/13

U.S. CAD



10

that you do not need to track model changes and modifications, as the test will always be performedon the most up-to-date version of the model files.

All navigation tools and various display options are available to allow you to better understand theclash, and clearly see the issue within the context of its surroundings. This makes it easier to reviewand decide on the best course of action required to resolve the issue, while clash status levels help tomanage the results list.

Communicating the necessary changes can either be done through a published version of theNavisworks model, or through a report such as HTML. The report contains details of the performedtest as well as each result. This includes details of the clashing items, the source file name, anyassociated comments that have been added, and also a screenshot of the issue. This allows theresponsible design team to locate the item in the original design application, understand what the

issue is, and make the necessary changes.

Once the design file is replaced with the modified version, opening the Navisworks file will load in thelatest version and the clash test can be updated. Navisworks re-runs the test against the up-to-dateproject model, and will automatically update the result statuses if the changes have resolved theissues. Its also worth noting that Navisworks will also identify any new clashes that result from thedesign modifications.

Navisworks can also be used to find duplicate geometry or test for clearances. Duplicate geometrymay result from modeling errors, and are important to find when taking quantities and calculatingestimates from the dataset. Clearance tests differ from Hard clash tests in that rather than looking for

physical intersections between objects you looking for instances where an object comes within aspecific distance of another object. An example of this would be checking for adequate clearancearound a piping system in order to insulate it.

Sectioning tools can be used to help see issues more clearly. Occasionally you will be able to seethat an object in the model is involved in multiple clashes. Rather than treating these as separateclashes, you can automatically group them together in order to treat them as a single issue, whichaids clash management and saves time, while maintaining an audit of all clashes found.

Measurement tools are available to understand the distances between objects, including a featurewhich calculates the closest position of two selected objects. This may be useful when objects run indifferent planes, for example, where a clearance issue may only be at a specific point where theobjects cross, and may therefore be discounted.

I mentioned earlier that by defining clash tests using search sets keeps the tests up-to-date. Theresan additional benefit to this too as the tests are based on property information, then they are not


11/13

U.S. CAD



11

tied to any particular model. Navisworks allows you to export the clash tests so that they can beimported into other projects that may not take the same architectural form, but follow a similarconstruction recipe thats to say they contain similar construction components.

PROJECT SCHEDULING AND 4D SEQUENCING

The traditional visualization of a construction schedule is the Gantt chart, however when youredealing with thousands of construction tasks its difficult to see how they all impact each other.Especially if you wish to see what effect a delay in task X has on tasks Y and Z, and the subsequentknock-on effects.

Construction planners are currently using applications such as Primavera Project Management,ASTA Powerproject, or Microsoft Project to create their schedules, and functionality exists withinthose applications to carry out What If? scenarios. Through BIM you can now take this further,bringing the project schedule into a digital reality. Utilizing the 3D models created as part of the BIMprocess and the existing construction schedule, the two can be united in Navisworks to create a 4Dsequence (where 4D = 3D + Time).

The models created through BIM are incredibly detailed, and the rich property information they inheritmake it easier to group objects that are to be constructed together, for example all of the first floorcolumns, or structural framing. And by creating a construction model, you can model buildingcomponents in the way that theyll be built. Take floor slabs for example. Traditionally a floor slab

would be modeled as a single object, though in reality it will be constructed from several sections, orpours. When creating a construction model from a conceptual model, floor slabs are one examplewhere objects can be split up to reflect a greater level of reality. These objects and groups in theconstruction model can then be assigned to the corresponding task in the schedule. When thesequence is played back you see a simulation of the buildings construction. This allows you tovisualize the construction process, identify areas of conflict between disciplines, or areas ofcongestion on the project site, and provides the opportunity to adjust and fine-tune the schedule.

The 4D sequence can also include staging of materials, positioning and movement of cranes, vehicleaccess, and so on, allowing you to experience the entire construction process.

Once the schedule has been linked with the model, you can quickly and easily synchronize with

modifications in the schedule, and simulate various What If? scenarios. This provides constructionplanners with more time to optimize the schedule, giving confidence that the building can be built tothis schedule, and helping you to manage risk and avoid costly on-site delays.


12/13

U.S. CAD



12

The Navisworks simulation can be played, paused, and reviewed at various stages throughout theproject, and viewed from multiple vantage points. Simulations can also be exported as renderedmovies which can be used for client presentations, or in helping raise public awareness andacceptance.

OPERATIONS AND MAINTENANCE

The life of models created through the BIM process does not necessarily end once the build iscomplete. As these models accurately represent the as-built project, owner operators have theopportunity to repurpose this data during the build, and throughout the life of the building. Forexample, if the project is residential apartments, then the BIM could be used for marketing

visualizations, or to allow potential clients to experience their apartment before its built. During theoperation of a building, the BIM could be used for facilities management or asset management, byintegrating the model to specific database-driven systems. From a maintenance perspective,inspection reports and digital images for example, could be linked to the relevant assets within themodel.

EXTERNAL DATA LINKING FOR OWNER OPERATORS

Through the adoption of this BIM for construction process, you have an additional opportunity to setyourself apart from the competition. When the finished building is handed over, youre also handingover a consistent, coordinated set of construction documentation, and a data-rich 3D Navisworksmodel that faithfully represents the as-built building. Owner operators can extend the use of thismodel into their operations and maintenance, asset management or facilities management processes

Every object in the model has a unique identifier, which allows for it to be tracked within an externaldata source. This could be as simple as tying desks in the model to an employee database, or tyingequipment to an asset management system.

The Navisworks interface is intuitive and easy to use, and requires no CAD skills, so is ideal for this

purpose. The visual nature of the building also makes it familiar and understandable to non-technicalusers, making it suitable for facilities management.


13/13

U.S. CAD



13

From a maintenance perspective, an issue with a boiler for example, could be tagged within theNavisworks model, storing a viewpoint of the particular boiler and comments regarding the issue. Youcould even take a digital picture of the issue and keep a record of it by linking it to the object in themodel. This can then be tracked regularly to see if the issue worsens, until remedial action is required

These are just a few examples of the way that the model can continue to be used long afterconstruction has finished. And through the API (Application Programming Interface), Navisworks canbe further customized to fit into more complex O&M processes, with the digital model at its center.

CONCLUSION

While architects and architectural engineering firms are adopting Autodesk BIM solutions for design,the power of BIM can be truly leveraged in construction. Autodesk Revit products can be used toefficiently create accurate, data-rich models from 2D designs. These facilitate Estimators to useAutodesk Quantity Takeoff, and spend less time counting, and more time estimating; ConstructionManagers can better manage risk by using Autodesk Navisworks Manage to digitally coordinatedisparate project disciplines before work begins on-site; Construction Planners can use AutodeskNavisworks Simulate for 4D sequencing in order to visualize the construction site and optimize theconstruction schedule; and finally Owner Operators can use Autodesk Navisworks Review to link themodel to their operations and maintenance systems.

These Autodesk BIM solutions can not only help you to manage the entire construction process, they

also allow you to set your business apart from the competition demonstrating your competence,providing confidence in your estimation, and ultimately helping you to win new, and repeat business.

s6-2 bim for construction

Documents