Damian Serrano, Assoc. AIA, Project/BIM Coordinator - RLF Inc. Kyle Hingst, LEED AP, BIM Manager - Balfour Beatty Construction MP5031 Autodesk Navisworks has become a must-have tool for general contractors, thanks to its robust features for clash detection and 4D scheduling. Unfortunately, these tools are not being adequately utilized by A/E firms. This class will illustrate how Autodesk Navisworks can be incorporated into your regular QA/QC process, as well as for internal coordination of multiple disciplines. We will also demonstrate how Navisworks can be used as a powerful visualization tool to create imagery for design and presentation purposes. This class will feature management and technical tips, as well as the use of a case study project to illustrate the concepts. Learning objectives After completing this class you will be able to: Incorporate the use of Navisworks as a milestone in an architecture project schedule Implement a workflow to create and exchange Navisworks files with multiple disciplines and consultants Perform 3D coordination as part of the QA/QC process of an A/E firm Leverage the use of Navisworks for presentation purposes, creating images, walkthroughs, etc. About the Speakers: Damian is a Project/BIM Coordinator with RLF, a nationally recognized A/E firm specializing in healthcare and government projects. With 20 years of experience in the AEC arena, Damian has been a key player in RLF's migration from CAD to BIM. Damian is a Revit Architecture Certified Professional and also an Adjunct Instructor at Seminole State College of Florida and Valencia College. He implemented the first BIM/Revit class at college level in the Central Florida area. Damian has a degree in Building Design and Construction and an Architecture degree from University of Buenos Aires, Argentina. damian_serrano@rlfae.com Kyle is a BIM Manager with Balfour Beatty Construction, and he is based out of their Dallas, TX office. Currently, he is located on-site at the Ft Riley Replacement Hospital project where he is responsible for all of the BIM initiatives and goals for the project. Kyle is part of Balfour Beatty Construction s National BIM Work Group where he helps develop and facilitate national BIM training and Standard Operational Procedures for the company. Kyle received his Masters in Architecture from the University of Nebraska and has gained valuable project exposure in multiple roles including Architect in training for a large A/E firm, Preconstruction, Project Management, as well as his current role in BIM. khingst@balfourbeattyus.com
Introduction One of the most amazing things of working with BIM is that you are creating a virtual representation of a building, a 3D model that is at the same time the source of your construction documents and your 3D presentation/visualization. There is no way to fool yourself about a project in BIM: you open a 3D view and immediately you can see where are the parts of your project that need attention and more development. However, the list of things you can do with a BIM project does not stop there. Analysis of the models is one of the BIM differentiators from CAD technology. Analysis is for us the ability of testing the building model to understand how the project is going to perform and be built. For example, 3D coordination of the models, a.k.a. Clash Detection, is one of the basic tools of analysis in a building model. Clash Detection has been used for many years in plant design projects such as oil refineries, power stations, offshore platforms, etc. and gained rapid popularity in the commercial building industry as more and more projects are being designed in 3D from inception. Autodesk Navisworks is currently one of the best tools for Clash Detection. Originally known as NavisWorks JetStream, the software was developed initially by Sheffield, UK based NavisWorks, and purchased by Autodesk in 2007. Autodesk Navisworks has been rapidly adopted by large contractors as a way to study constructability of a design, even in projects not originally designed with BIM technology. That means that if you as an A/E firm are not yet using BIM, chances are that the GC in your project will pay to get your project in BIM and perform Clash Detection on it, finding most likely thousands of problems that cannot be found in 2D representation. At RLF, we started implementing Revit six years ago and we are today a 100% BIM firm, including all disciplines, Arch, MEP, interiors, Structural. The use of Navisworks was a natural evolution of utilizing BIM technology. A couple of projects we worked on in the last few years triggered the need for developing an in-house procedure to run clash detection exercises at different stages of the project: the massive 1.5 million s.f. VA Medical Center in Orlando and the 550,000 s.f. Irwin Army Community Hospital at Ft. Riley, KS, both under construction today. In both projects the early involvement of the contractors facilitated the 2
discussion about constructability and 3D coordination, making us pushing the envelope in search of a clash detection process that can be applied in all our projects as a regular QA/QC procedure. The use of Navisworks to perform Clash Detection created a lot of discussion in the office. Concerns about responsibilities and liabilities surfaced quickly, as the different disciplines faced with the reality that today is just not enough to propose a design solution and let the contractor coordinate it. The design professional today is required to present a design solution as coordinated as possible. For instance, the BIM Implementation plan for the Ft Riley project said clearly: Design Coordination[:]... Autodesk Navisworks will be used for model coordination periodically throughout the Design process for periodic model reviews and to spatially coordinate building systems during the design process... Purpose[:] Spatial coordination of all building systems to verify design intent and establish that all systems have the space required to be installed where shown. This is a key design quality control process to reduce system conflicts prior to design completion. This process is not intended to produce a clash free model, but to find major spatial conflicts and ensure all building systems are located in the ceilings, walls, shafts, etc. Detailed, clash free coordination is conducted as part of the Clash Detection Process. Clash Detection [:]... is a process that replaces 2D construction CAD file overlays, which were commonly done on light-tables in the past. The Construction Team will utilize 3D models created by designers and subcontractors to assemble a composite 3D coordination or "clash detection" model using Navisworks. The fully coordinated models become the basis for subcontractor shop drawings. You can certainly expect similar reactions in your office as you implement this technology, although, if you have been implementing Revit in the past few years, you must be used to it by now. While working on developing a QC process, we realized that Navisworks is an impressive tool for quick visualization purposes and probably the only way of putting all the models in a project together to be navigated in an average BIM workstation. The fact that you can open the model and start walking around the building in the computer was an eye-opener to many senior-level staff that so far had been hearing the discussions about BIM implementation but were not hands-on the models. For many of them it was the realization of the power of 3D information as a design and analysis tool. The use of Navisworks for visualization was leveraged for all disciplines in our firm, creating imagery and walkthroughs to communicate design intent to the design team, contractors and clients. 3
Location of furniture and equipment, signage, quick fly outs around the building, etc, can be easily studied by exporting the walkthroughs in avi format, keeping an eye on project development as the design progresses. Navisworks Basics Packages and File formats Autodesk Navisworks 2012 comes in three different versions: Manage, Simulate and Freedom. Manage is the full version that includes the visualization tools, 4D scheduling, reviewing and clash detection. Simulate is similar package but does not include clash detection, so I would not recommend its purchase if you are trying to leverage this technology. Freedom is a free viewer that can open Navisworks as well as DWF files and is a great tool for Senior Project staff to navigate the project, access element properties and visualize saved viewpoints and walkthroughs. In the last few versions, a number of features that were only in the full version have been added to Freedom, a trend that all users would like to keep seeing in the future. Navisworks allows opening a large list of file formats, but there are three native file formats: NWC Navisworks Cache file When you open in Navisworks a file of supported CAD format, an nwc file is created automatically with the same name of the original file. Ironically, Navisworks cannot open a Revit rvt file, therefore the nwc files need to be exported from inside Revit with the Navisworks export add-in tool. Every time you open the CAD file again in Navisworks, the information is checked against the exiting nwc cache file; if the CAD file was updated, the nwc is updated as well automatically. Once again, unfortunately it is not the case with the Revit files, which need to be exported periodically. NWF Navisworks Working File 4
The nwc files are appended as links into an nwf file. The nwf format doesn t have any geometry it is coming from the linked nwc files- but is a master file that contains all the information about clash detection, review, markups, saved viewpoints, etc. As you go updating the nwc files from Revit, every time you open the nwf file you have an updated overall view of the project. NWD Navisworks Document File This is an output format that binds all linked nwc files into one composite NWD file for publishing purposes. An nwd file is like a snapshot of a project at a particular point in time. Exporting from Revit Typical export is one nwc file per Revit model. Every model should have set up a 3d view with the right settings. Export using the Navisworks 2012 exporter located at Add-Ins tab>external Tools>Navisworks 2012. 5
You can also export multiple nwc files per Revit model, i.e. broken down by floors. This is helpful for large projects, and to avoid the use of search sets. This also address the issue of mechanical objects not reporting the level. Column Grid marker model, auxiliary model to show the grid numbers at the column locations. This is a separate Revit model exported to nwc. Column grid marker family. CAD exports of floor plans, are exported from Revit. The CAD export are laid out at the floor slab level to help while navigating the model with the interior partitions turned off. Creating the nwf file 6
Append all the nwc files. It is very important to use shared coordinates when exporting so all models fall in place. CAD exports may need to be adjusted their elevation with the transform tool. You can apply color overrides to models of different disciplines to facilitate visualization during navigation. Create search sets as needed. For example turn off floor slabs to avoid ignorable clashes vs. piping. Find items and then save the search. Then select the set and hide it. When you hide something in Navisworks it is not considered for clash detection. 7
Clash Detection as milestones in the design process When should Clash Detection be performed in the design process? This needs to be discussed in your office. Navisworks is not a very complex software package. The development team has kept the program easy to use and understand. However to successfully utilize it a process needs to be establish, and here is where contractors have taken the initiative, outpacing most of the A/E firms. It is obvious that in order to run clash detection you need to have a 3D model, that s why is so important to start working in BIM from the inception of the project. We have identified three stages of a project when Clash Detection should be run. Clash Detection at 35% Construction Documents Stage One: Structural vs. Main MEP System Components At 35% development, a project should have most of the architecture components placed in the model and the systems should have at least the main components and pieces of equipment. This is the moment when you can start running clashes of structural systems versus MEP systems. Although the MEP system won t be fully developed yet, here you can start finding conflicts between main structural members and mechanical equipment, main ductwork runs, panels, etc. The design team should run the clash detection, issue reports and start reviewing them to address the clashes and make necessary changes in the design. Clash detection at 65% Construction Documents Stage Two: Structural vs. MEP and MEP vs. MEP At 65% the architecture and structural model are much more refined and the MEP models should be very close to be fully developed. This is the time to run again Structural vs. MEP systems to verify that clashes from the previous stage where addressed and find new clashes as a result of the development of the project. This is a good time to also run clashes of MEP vs. MEP, this is ductwork vs. piping, ductwork vs. cable trays, etc. Typically this where the bulk of the clashes occur, and is a good moment to have the different engineering disciplines to coordinate the layout and routing of the different systems. 8
Clash Detection at 90% Construction Documents Stage Three: Structural, MEP and Ceiling Coordination 90% CDs is for us an instance when the project is almost finished. The models should be complete and it gives you the possibility of re-running all the clashes of the previous stages plus new clashes on areas of the project that require multi-discipline coordination, i.e. the ceilings. Creating clash reports of ceilings vs. MEP and Structural system is a great help to find problems in convoluted areas, recessed ceilings, soffits, areas with bracing for ceiling mounted equipment, etc. Clash detection is an exercise that can be as precise as the models you are running it on. This is another reason to be as precise as possible when modeling your buildings and incorporate 3D information that is helpful to achieve this. The quality of the content used in the models is a key factor here. While it is not necessary that the families have every nut and bolt, it is important that contain information that can be useful for the clash detection process, i.e. families that have clearances incorporated as geometry. Running the clash tests Create a new test and select models or search sets to clash, may be multiple. Settings and tolerances. Sort clashes. Some of them may be ignorable, mark them as reviewed (cyan). Otherwise leave them as active (orange) 9
Reporting clashes Once the clashes have been sorted out, you should have all clashes to be reported as Active (showing with an orange dot). The clashes that are ignorable are marked as Reviewed (showing with a cyan dot). Go to the Report Tab and under Contents, check the boxes of the fields you want to include in the report. Typical fields to be included are the Item ID, the Layer of the object (which reports the Level where the object is hosted in the Revit model), and the item name (which gives you the name of the Revit family). The Item or Element ID is important to find the objects back in the Revit model and fix the clashes. Under Include Clashes, check only the Active clashes, as you typically don t want to export all the ones that have been ruled ignorable. For Report Type, use Current Test, as you typically want to generate one report 10
per clash batch. You could also choose All tests (combined) and All tests (separate) if you want to speed up the procedure. For Report Format, use HTML if you are planning to open/edit the report in MS Word, or HTML (Tabular) if you are going to open/edit the report on MS Excel. We typically export in both formats, the HTML can be opened in MS Word and printed to PDF to generate a report book that can be distributed to team members. The HTML tabular is open/edited in Excel to generate a matrix where comments and other information may be added by the designers addressing and fixing the clashes. Editing the HTML Clash Report in MS Word When opening the HTML in Clash Report in MS Word it typically won t look readable and some tweaks may need to be done before you can print to pdf. One of the problems is that the item properties don t show with proper spacing. To fix this, the HTML file should be tweaked with the following procedure: 1. Open the HTML file with Notepad. 2. Hit CTRL-H. In the Replace dialog box, enter this in the Find What box <span class="namevaluepair"> And then enter this in the Replace With box <span class="namevaluepair"><br> And hit Replace ALL. 3. Then save the document. Then open the HTML file with Word and you will see the item properties show one per line. Save the HTML and then save as.docx format to create a final report. The report will look well presented if you show one clash per sheet, which may be achieved by adding or removing lines, or sometimes just by adjusting slightly the size of the first pictures, the whole document gets arranged one clash per sheet. Editing the HTML Clash Report in MS Excel The HTML Tabular report can be opened in MS Excel, which will give you a spreadsheet report very well presented. A few additional tweaks should be added like modifying the title and adding a couple of columns (we use background color green for 11
them) for the designers to add comments when addressing the clashes. Reporting Clashes as Saved Viewpoints The clashes can also be saved as a viewpoint. In the Clash Detective dialog, under Report Format you can select the option As Viewpoints. When writing the report, Navisworks will generate a saved viewpoint for every clash in the report, grouped by Clash Batch. The result can be seen in the Saved Viewpoint dialog. Publishing the NWD file An NWD file is basically the nwf with all the linked nwc models bound into it. The links to the nwc files are severed and all the geometry plus all the reviews, markups, clashes, etc. become one single comprehensive file that can be opened both in Navisworks Manage or Navisworks Freedom. Since the links to the nwc are broken, the NWD file becomes like a snapshot of a project at a particular point in time. 12
To Publish the NWD file go to Output tab>publish panel>nwd. From the dialog box, you can fill out the parameters Title, Subject, Author, Publisher, Published for, Copyright, keywords and Comments. You can also restrict the access to the NWD file by adding a password to open it. You can also check the Display at password checkbox, so anyone opening the NWD file will see this dialog box and have access to the publisher information to request the password. You may also add an expiration date to the NWD file, after which the file can t be opened. Finally when you click OK, you can specify location and name for the NWD file. Solving the clashes in the Revit models Engineers address the clashes and post comments to the excel spreadsheets. 13
How Contractors Utilize Design Models BIM Execution Plan A successful project incorporating the use of Building Information Modeling workflows starts with the BIM Execution Plan. This plan sets up clear guidelines for the Owner, Design Team, Construction Manager, and Subcontractors which outlines project expectations and deliverables. One of the essential tools of this document is the BIM Model(s) Content Responsibility Matrix. This document is based on contractual requirements which are further broke down into what level of detail a particular element is required, who develops the element, and at what time during the project it must be delivered. Clearly communicating these guidelines during the planning phase of a project ensures that all parties understand the project expectations. Coordination Kick-off Meeting Similar to the Project Execution Plan, Construction Managers must clearly communicate the project expectations with Subcontractors prior to joining the project team. These expectations are outlined in the Construction Manager / Subcontractor contract and later reinforced during the BIM Kickoff meeting. Again, the BIM Model(s) Content Responsibility Matrix becomes the basis of what models were developed by the design team and to what level of detail (LOD), what content needs to be created by the subcontractor and to what LOD, and when the model content will be needed as it relates to the Project CPM schedule. 14
It is important for Construction Managers to clearly communicate the clash resolution hierarchy and installation sequence up front. The clash resolution hierarchy allows subcontractors to understand who has precedence when an agreed upon resolution cannot be achieved. Indicating this information is critical to ensure that coordination occurs in a timely manner and will not delay the coordination schedule. The installation sequence generally helps MEP subcontractors understand what elevation their system should be modeled. Again, laying out the basic expectations guidelines helps expedite the construction coordination process. The coordination kick off meeting is also utilized to clearly indicate the technical aspects of the coordination process which includes: Electronic File Sharing, File Naming, Model extents (IE Level 2, Area B), X Y Z model coordinates communicated and shared with an insertion point file, to name a few. These items will be discussed in further detail during the Construction Coordination section. File Sharing At Balfour Beatty Construction we utilize the Design Team models similar to electronic 2D CAD file sharing. Typically, we are asked to sign a holds harmless agreement clause with the Design Team, which in turn is required by any of our subcontractors prior to utilization of any of the model files. This eliminates risk associated with sharing the design models as the 2d drawings and specifications are the contractual binding documents. Construction Managers / Subcontractors receiving the design models should heavily scrutinize the model information content as they become responsible for the information which is received by these models. The following Construction Team workflows are heavily dependent on Design Model content which includes: Quantity Extraction While it is true that model-based quantity surveys through Autodesk QTO can be performed considerably 15
faster than traditional methods, it is important to understand that the accuracy of the material take-off is directly dependent upon the model accuracy and the method by which the components were created in the model. With this understanding, Construction Teams utilizing design models for quantity extraction can expect much of their efforts ensuring the accuracy level of the model. Once the model has been analyzed, Construction Teams determine what components will be utilized for quantity extraction and verification. Visualization BIM allow the Construction Team to visualize critical aspects of the project to verify they meet the project goals and intent. Verifying finishes, clearances, and the spatial arrangement of building components help to ensure the contract document requirements will be achieved. Furthermore, Construction Teams can navigate through a virtual model of the facility to better visualize and inspect the project design prior to construction. 4D Scheduling / Sequencing Using Navisworks Timeliner for 4D scheduling and sequencing is another important tool used to help Construction Teams develop / verify CPM schedules. The 4D model can be used to analyze the logic and feasibility of the CPM schedule. Ultimately, allowing the Construction team to gain confidence in the construction schedule by verifying the CPM schedule in a visual manner. The 4D model provides enhanced schedule management through monitoring current progress and forecasting project schedule constraints, sequencing issues, trade overlaps, safety concerns, and changing site conditions. 16
Construction Coordination Process and Tools As previously discussed in the BIM Coordination Kick off Section, clearly communicating the process and expectation can determine the success or failure of a well executed coordination plan. The following tools and techniques will help facilitate a systematic approach at resolving discovered clashes to ensure a successful outcome by all stakeholders involved. File Naming It is important to develop consistent file naming standards for the composite model to ensure a quick and easy file reference. This will allow the entire coordination team to easily identify and organize the clash batches. Inconsistent file naming can often cause confusion among the team. Ultimately, leading team members to work with out of date models and wasting valuable schedule time. It is important to find a system which is simple, easy to understand, and consistent. Clash Resolution by System When setting up batch tests, it is important to keep tests limited between only two different systems. This allows the BIM Integrator to run clash tests based on the clash resolution hierarchy. Furthermore, breaking down the clash tests into small manageable groups allows you to quickly understand what systems have the most coordination issues. Also, this allows the involved team members to quickly identify which batches they should reference when reviewing their coordination issues. Clash Resolution by Floor and Area One of the most important aspects of analyzing clashes in construction coordination is to subdivide your model into smaller, more manageable areas for review. The first step is to break down models by level and area, then further subdividing the model into small areas based on priority, such as corridors, shafts, and pinch points. Utilize Navisworks functionality to locate the clashes, but utilize the viewpoints tool for outlining the sequence of review based on priority. This will allow the team to address priority issues rather than the individual clashes. This will further expedite the process as one coordination issue can 17
often be identified as 30 or more clashes based upon how the component was modeled. Ultimately allowing you to have a true understanding of how many coordination issues exist opposed to how many clashes have been identified. Creating Viewpoints Creating a viewpoint is simple. Navigate to the viewpoint tab or right click within the viewpoints section to add folders or new viewpoints. When creating viewpoints, keep in mind that organization, naming, and number identification plays an important role for tracking issues. 3D Grid Markers When reviewing coordination issues, one of the first things the facilitator must do is orient the team to the area of the building in which the coordination issue exists. This can cause confusion among team members and result in team members addressing the wrong issue or the team spending unnecessary time identifying the clash location. One way to eliminate this unnecessary issue is through the use of grid markers. Setting aside a few hours at the start of the project creating a grid markers file is just as important as developing gridlines in 2D plans. 18
Tracking Coordination Issues Utilizing Viewpoints can help the coordination team to track information both in the model and the through the Navisworks viewpoints.html export functionality. First, viewpoints saved in the model, can be exported or saved from one composite model to the next. If a coordination issue has been resolved from one version of the model to the next, it will clearly be understood in the model as the saved viewpoint will no longer show a clash in the new composite file, which is can quickly be reviewed. Next, exported viewpoints, allow the team to review the coordination issues without opening a model for quick reference. (before and after viewpoints) Post Construction Coordination Upon completion of Construction coordination, subcontractors are able to confidently use their system models for Pre-fabrication / Pre-Assembly, Automated Layout, and As-Built models. This allows subcontractors to bid projects schedules more aggressively, improve the quality of the deliverable, and add value to the project. 19
Navisworks as a visualization tool in the A/E firm Navisworks includes a number tools to navigate the model, allowing the designers to validate the design communicate it to clients and consultants. You can save viewpoints representative of the project and come back to them later to track modeling progress. You can also put together multiple viewpoints to create quick walkthroughs of the building. It is recommended to keep the visualization tasks separate from the Clash Detection process. They have different needs and happen at different points in the design schedule. While the Clash detection happens as milestones in the design schedule, visualization works more as a routine task. Clash Detection requires saving the nwc files for future reference a document the reports and published nwd files. Visualization tasks are dynamic in nature. You should create nwc exports, separate from the ones used from clash detection, integrate them in an nwf master file and generate viewpoints and walkthroughs. The nwc models are updated as often as you want, allowing you to see the updated project every time the nwf file is open. Ideally, the models could be exported every day to be available always for project team and managers. Creating Saved Viewpoints As we go navigating the model, any representative viewpoint can be saved with a name. These viewpoints are like pictures of the model that can be saved by simply going to the Saved Viewpoint dialog, right click, pick Save Viewpoint, give it a name and hit Enter. Similarly, folders can be created and views grouped into them by dragging and dropping. 20
Walkthroughs The animations may be created in two ways: 1. Recording live as you go navigating the model. This is faster but requires great skill in the use of the navigating tools. 2. Assembling a number of saved viewpoints that are used by NW as key frames. When you play the animation, the intermediate frames are added. This is the preferred option in our office. To record the live navigation, go to the Animation tab, click on the Record button and NW starts recording all your movements. Click the Stop button to finish the animation, which is automatically added in the Saved Viewpoint dialog for you to assign a name. To create an animation with saved viewpoints, you go to the Saved Viewpoint dialog, right click and pick Add Animation. Then give it a name and hit enter. Then drag the viewpoints you want to use as key frames and drop them on the animation name. To play the animation go to the Animation tab, find it in the pull-down menu and click the Play button. Output methods Saved Viewpoints may be exported as simple Images or Rendered Images. Both options are available in the Output tab, Visuals panel. Both have similar settings, you can control the file format and the image size. Images have also an anti-alias setting. Animations may be exported in two ways: 1. As a video file in.avi format 2. As a series of pictures that can be assembled in a video editing application. This is our preferred option, since it allows to better control the video file format, file size, quality, etc. In our office we export the images to.png format, at a rate of 25 frames per second (fps). The result of this is a large number of image files, named with a consecutive number. To assembly and edit the video you can find different applications, many of them free, on the Internet. At the office we have successfully been using VirtualDub, a very simple freeware to compose images and run a video from them. The interface is very easy to use, just take the images from Windows Explorer and drag them on the VDub window. The settings include the frames per second, file format, compression codec, etc. In a few minutes we obtain 21
a good quality walkthrough that can be used as a communication tool for the design team, consultants and clients. 22
Conclusion Oftentimes we have discussions with colleagues and students about the power of a tool like Navisworks in the A/E office and I hear that NW is the QA/QC tool of the future. In my opinion this is not true; Navisworks is the QC tool of the present. This technology is available here and now, and any firm not using might be delivering projects less coordinated and with bigger risks of additional costs and constructions delays. In addition, not using Navisworks means missing a fantastic possibility to visualize, navigate and get immersed in your projects with the purpose of validating your proposed design. These and many other features of the software (reviewing tools, animated 4D scheduling, photorealistic rendering, etc.) make Autodesk Navisworks a tool that should be used by any A/E firm that wants to deliver outstanding services to their clients. -Damian & Kyle November 2011 23