Notes on BIM Collaboration across Multiple Offices

At PAYETTE we believe in partnerships and we have a history of collaboration with our architectural peers to learn, share and practice.

Last year we began Construction Documents for the Milken Institute School of Public Health at George Washington University. For this project, we partnered with Ayers Saint Gross in Washington, D.C.  With a history of BIM and project collaboration dating back to 2009, Carolyn Hoef from Ayers Saint Gross and I were tasked with creating a BIM strategy to carry the team through Construction Documents and Construction Administration. Our strategy needed to address: design ownership boundaries, co-authored sheets and model and family sharing. While we both brought strong Revit and BIM skills to the team, we learned many valuable lessons along the way. The following are some guidelines to assist in navigating through BIM collaboration across multiple offices.

Establish a workflow within the files and how information will be shared between offices.

Ask:
Will you have separate files and link them together?
Will you remote desktop into one office and work from one central file?
Will you take advantage of the Revit Server or BIM Clouds out there?

When our team began this process, virtual clouds were relatively new so we hesitated to implement them. We selected the more conventional method of linking separate central files, which allowed us to avoid large files through Construction Administration.  We allocated Remote Desktop capabilities in the event immediate access was required to the respective models. For this workflow, this process proved to be very beneficial and we highly recommend implementing as early as possible. Weekly progress postings were also applied, with increased frequency during deadlines.

Define the boundaries of your scope.

If you collaborate with a partner architect, project scope is well defined in the contract, but this distinction is different than dividing the BIM work. While awareness of the contract is imperative, drawing and model ownership decisions take an alternate perspective. It’s common practice to break a model into Core & Shell and Fit-Out, but that split may not work for your team. In our case, it didn’t. Instead, we selected an interior boundary, which splits the building into relatively equal halves and hugs a gridline; we call it the “C-Line Wall”. In our case, the “C-Line Wall” is a grouping of wall assemblies over 9 floors with many ins and outs – suite entrances, service entrances, and program changes.

Navigating a shared interior boundary requires special attention to wall assemblies and thicknesses. If possible, set reference planes to establish important datums and maintain them throughout the duration of the project as “check points.” Remember, in Revit, you can’t join walls in separate models. Instead, a line exists where the two walls meet in plan and a strategy for the team should be defined for clarity and graphic purposes.

Different firms have varying electronic standards, and templates and conventions. In the BIM world this also means varying project file templates, families, detail components and even line styles. Choose one team to lead file set-up and commit to using one firm’s library of families and graphic standards. This ensures users implement the same line styles, naming conventions and annotation symbols throughout the course of documentation. Establishing shared elements like grids, project base point, and levels are important in ensuring model, drawing and graphic coordination. Scheduling items like doors and casework across linked models will benefit from this process in turn, as the families will already have the same parameters needed for scheduling.

Overall plans and ceiling plans at 1/8” scale are co-authored by our two firms. Thus visibility of the layers of construction documentation information is critical; and dimensions, tags, and keynotes that are drawn in one model need to appear as intended when linking into the partner model. We achieve this in our linked models utilizing the “by linked views” setting,  a standard Revit setting allowing the linked view to appear exactly as drawn in the host model.

The “by linked views” setting allows visibility of model elements, annotation symbols, detail line work and dimensions. However, reference view tags such as section markers, elevation markers and callouts do not appear in the host model. For example, an enlarged plan callout in the partner file will simply not appear when linked into the host file. To work around this issue, we coordinated “dummy views” in the PAYETTE model – that is a callout, elevation tag or section marker drawn in the PAYETTE model that navigates the audience to the correct sheet. This means establishing sheets for the sole purpose of navigation, and excluding them from the print set.  And by default, the PAYETTE model became the only model capable of printing the co-authored sheets for documentation.

Fast forward to Construction Administration and we have encountered another obstacle. Although all revision bubbles drawn in the partner half of the building appear, their associated tags are not visible when linked into the host model. Tagging elements across linked models is possible – that is, I can tab select an item in the partner model and use my annotation symbols to tag it. However, when tagging a revision bubble that originates in a linked model, the reference number in the triangle appears without a number. Instead, the workaround we’ve devised requires us to draw and tag all revision bubbles in the host file.

Collectively we have learned a lot about BIM collaboration across offices of the same trade, and we continue to learn. Similarly, BIM software is quickly evolving and responding to user needs. BIM Cloud software is steadily improving and emerging as a viable solution to many of our collaboration obstacles. In fact, we are currently exploring the possibility of implementing a cloud through Construction Administration. There are alternate workflow processes for some of the obstacles we have encountered, and with software and personal advancements we will continue to seek for ways to improve our BIM collaboration workflow. Successful collaboration across offices takes planning, so remember, critical thinking about key items such as file structure, scope definition, shared model elements and co-authored drawing coordination will help get your team started in the right direction.

This post was co-authored by Cara Gastonguay, Associate AIA LEED AP, PAYETTE and Carolyn Hoef, Associate AIA LEED BD+C, Ayers Saint Gross.