Multi-Building Coordination
Hello,
I am starting this discussion to find out how others are coordinating multi-building projects. Our team is coming from a BIM360 Model Coordination background, where you would set up a Model Coordination space for each building, and another for site utilities. With Revizto, I feel like this can be achieved in a single project. See below for my current theory on how this would work.
1. Once Horizontal control is received from the design team, the Architectural and Site Grading model Survey Point is set to "Civil Coordinates". The Project Base Point is then placed on an agreed Grid Intersection for each building. This allows each sub-contractor the ability to choose how they want to setup their Revit/AutoCAD project.
2. A new Revizto project is setup and the model positioning is set to Shared Coordinates.
3. Each subcontractor will have a separate Revit/AutoCAD Project for each building, and will have to choose an alignment point described in step 1. If the subcontractor uses Project Base Point, we add a Scene Transformation by calculating how far the Project Base Point is from the Survey point. If the subcontractor chooses to align to Civil Coordinates, then no further work is needed (this will be recommended).
Pros: This will allow for easy coordination between the site and building utility subcontractors. All issues can be tracked in one place and will allow the field team to view all buildings on the mobile app in one project.
Cons: For our past Revizto projects, we set up a Level and Grids model to remove excess levels. One possible issue is that multiple buildings will have the same grid letters/numbers, same level names and different finish floor heights. Revit does not allow the same grid/level names. So I am wondering if it is best to have a Level/Grid model for each building, but I am curious on how an issue's metadata will read that? For example if I want to filter clashes on the First Floor level and there are 3, how will that work? I assume we will need to use Zones instead.
Please note that I have not tested any of this, and that's why I am reaching out to the community to see if anyone has come across a workflow. I look forward to reading any input on this topic.
-
Hello Anthony,
Allow me to clarify how levels and grids function differently within Revizto. This should help with your setup.
Levels - Levels for the project are determined by one model. Those levels are boundless.
(This can be problematic when buildings have a "Level 1" at different elevations.)Grids - Project grids can be set from different models as long as they have been exported. The grid numbers do not have to be unique.
What about zones…
Zones - Special 3D objects created for locating issues and organizing clashes. Zones report back when an issue or a clash is created inside the zone “volume”.
You could divide up the zones per building and per level. Building A + Level 1, but if you wanted to use the zone for construction zones then you would end up with more zones to account for the buildings and levels.
But there is a little used piece of meta-data we do bring in from Revit…
Area - These flat, 2D areas, typically used in early architectural design to denote occupancy types. But could be used as ‘levels’. Even though they are ‘flat’ they will report issues within the area boundaries and above.
Well, then what do we do with levels? You could choose not to set them up in Project Properties to avoid confusion. But since levels span the whole project site, you could make the levels elevation datums.
I will put together a sample project to demonstrate.
-
Here are a few screenshots of a simplified version.
- The main building only has one area per level and extend outside the building as you can see in the 2D.
- The secondary building has areas for the 'podium' and each 'tower', level 3A and level 3B, not shown.
- Levels are in created in an empty file with a level for every 5m. (The model includes model line crosshairs at Revit origin.)
-
Laura - Thank you for taking the time to provide this input. From your explanation, I think it will be best to have a single Level/Grid model, and in cases for duplicate level/grid names then we can simply add a prefix to the name (Ex: Grid AA, Bldg A - FF). With Zones, I think it would be best to have a Zone at each level in the building as you mentioned.
To answer Federico's question, the value for us is having site utilities and building utilities in 1 space. In some of our projects, we coordinate site utilities heavily and input lots of survey/drone data throughout the project that can be used in Revizto. For a project that has multiple buildings and little site work, then I think we will just have a project for each building under 1 Revizto license.
I will be setting up a new project that will follow what we discussed here in the next few weeks. Once I have a final workflow down I will make sure to share it in this discussion.
-
Hello All,
With the information provided in this discussion we were able to successfully create a multi-building project that is currently being coordinated. Here is a breakdown of the workflow and the potential challenges you may face if you want to run a Revizto project like this:
The first piece of the puzzle is to establish good horizontal control for each building. 50% of the time, the civil engineer will provide good horizontal control with at least 2-3 coordinates at grid line intersections. This wasn't the case with this project, and the design team gave dimensions from new curbs to building corners. To find the coordinates we typically open the Civil CAD file, verify it's on a published coordinate system and locate the grids in the model. If you can't find grids in the CAD file, we typically export a floor plan in the Architectural Revit model to AutoCAD, import the floor plan into the Civil CAD file and align it to the building outline already in the CAD file. Next you will create/submit an RFI that provides coordinates of at least 2-3 grid intersections for each building and ask the design team to confirm the values. There's a small chance that you may get some pushback and the civil engineer may not confirm the values. If you are the CM, then you should be good to continue. Just make sure to relay your values to the surveyor so that everyone is on the same page.
Before coordination starts for the project, we create a Site Grading model in Revit. Site Grading models are crucial for our sitework contractors and help us find site related issues. I have found that the site grading model is perfect to be the host model for Grids, Levels, Areas and Zones.
- Grids: Import a Civil CAD file that shows grids and building outline and create the grids. The grid locations should reflect the horizontal control drawing or the RFI that you submitted. Revit doesn't allow duplicate names so make sure to find a neat way to make them unique.
- Levels: As Laura mentioned, it is best for levels to act as datum points. In our case we created levels for each building FF. See image below.
- Areas: Optional but are helpful for multi-story buildings since they can be used as a replacement to Levels. You will need to make sure you are drawing the area boundary in an Area plan that is hosted to the level that represents FF of the building. This is due to how Area's function in Revizto and Revit. See image below.
- Zones: In Revit use the Model is Place tool to create a "mass" around the building. It is best to follow the exterior building walls with a 5' offset since building utilities typically stop around that point. Once you do this for all buildings, create a final mass to fill up the void space between the buildings. This zone will be for Site Utilities. For heights, I found that it is best to go 15ft above and below the top and bottom constraints of the building. See image below
The next step is to publish all design Revit models to the Revizto model so that we can export sheets. Before you get started, you will want to confirm how the design team organized their sheets. This step is a lot easier if the individual building sheets came from individual Revit models. In our case the design team had a central Revit model for each discipline, with the individual building models linked in. This ended up becoming a mess, but we were able to make it work.
- If the design team has individual building models for each discipline follow these steps: Upgrade the model to the chosen Revit version, link in the Site Grading Revit model, align the site grading model to the building using grids, acquire shared coordinates, and create a 3D view for export. Once these steps are complete for all disciplines, open each model, reload the links to the upgraded models, then export to Revizto. It is crucial to reload the links before exporting sheets so that elements are not missing. You can save some time here by completing the steps above with the architectural model first. Then when you move onto the structural model for example, the link for the architectural model should already exist, so you can just reload from and select the architectural model that acquired coordinates from the site grading model. Then acquire coordinates from that Architectural model. That way you don't need to align a model every time. It will also help you find if Architectural and Structural gridlines aren't aligned.
Once this is complete for every building and discipline you should have the full set of drawings in the 2D tab. When sub-contractors start uploading their models, you can delete these design models. Sheets will not be deleted if you do this.
Something that I thought would be a struggle is having our sub-contractors align to the Revizto model. But so far we haven't had any issues. Since we upgraded the design models and set coordinates, anyone who is working in Revit is already good to go. For AutoCAD users we created a Master Grid file, which they can reference in and align to. For Tekla users, they can reference the horizontal control and use the Project Base point feature.
Although I didn't highlight every little detail this should be a good outline for setting up a multi-building project. We are a few weeks into coordination, and everything has been running smoothly, from clash automation to filtering issues. I am looking forward to reading any feedback and am willing to dive into more detail on specific steps.
-
This is amazing! Thank you so much for sharing your setup.
I appreciate that you shared how you worked with C3D and survey data to start the project off on the right foot.
I really like the use of a Grids, Levels, Zones file that can be shared to everyone creating content. It seems to have already been a great benefit.
Keep us updated on how it goes.
Please sign in to leave a comment.
Comments
6 comments