GBS versus Revit CEA

[Dupont]

Can anyone tell me why they would still use /need GBS if they are going to do the conceptual analysis with Revit's CEA tool. They are both used for early conceptual analysis but I would like to figure out what tools are really necessary. I have not done a complete comparative analysis and was hoping someone out there has on the need to use all the tools. Once Project Vasari is actually released then do we even bother with GBS and CEA? We all know Autodesk appears to be breaking Ecotect up and adding the bits and pieces slowly into Revit.

[Scott D Davis]

The tools in Vasari are for analysis of conceptual massing only. Vasari does not have tools for Walls, roofs, floors, etc., only Massing. The tools in Vasari are based on GBS, but can analyze Massing.

Now, the CEA tools in Revit use GBS, but are based upon the Rooms you place in the model...not Masses. So you need an enclosed space defined by walls/floors/ceilings/roofs (room bounding objects).

So use Vasari for analysis on the earliest design using conceptual masses. Then use Revit and the CEA tools once your conceptual model begins to include walls/roofs/floors.

[Dupont]

Thanks Scott. A few of more questions:

1. Any idea when Autodesk will make Project Vasari go "live" ?
2. Since Revit-CEA uses GBS, would (should) the analysis results be the same? You have more parmeters to set within GBS so that would affect the results. When does one really "need" to use GBS assuming that the design process beig pushed is through Revit?

3. Should the weather results (ie. wind roses, air temp and humidity) from CEA be the same as what would get using Ecotect's Weather Tool?

Autodesk has so many tools that architects are we are confused as to which one to use and when.

Thanks for the inputs.

[Scott D Davis]

Sorry, I need to make a correction to my post. I was confusing the Revit CEA tools, and the Revit Green Building Studio tools.

The CEA tools in Revit, and the tools in Vasari are the same. They both use Massing and the analysis is perormed on the Massing shapes.

Revit has the capability (Vasari does not) to run more detailed analysis on building form using walls/roofs/floors, because one can place a Room in an enclosed space and then Export to Green Building Studio using gbXML. Using this method, the Rooms are analyzed as a space.

So there's the difference: Revit and Vasari have the same Conceptual Energy analysis tools, using Massing. Revit has the ability to export Rooms/Spaces as gbXML using Green Building Studio.

Hope that clears it up!

[Scott D Davis]

1. Any idea when Autodesk will make Project Vasari go "live" ?

Not sure what you mean by this, as Vasari is already "Live" on the Autodesk Labs. Labs.autodesk.com

2. Since Revit-CEA uses GBS, would (should) the analysis results be the same? You have more parmeters to set within GBS so that would affect the results. When does one really "need" to use GBS assuming that the design process beig pushed is through Revit?

The results from a CEA run in Revit and Vasari wil be the same. The results from a gbXML study in Green Building Studio run on Revit rooms/spaces may be different, due to a higher level of detail in a model that consists of walls/roofs/floors, rather than just massing.

3. Should the weather results (ie. wind roses, air temp and humidity) from CEA be the same as what would get using Ecotect's Weather Tool?

Yes, the wind rose diagrams in Vasari are from Ecotect, just running inside of Revit.

Autodesk has so many tools that architects are we are confused as to which one to use and when.

Use Vasari or Revit CEA for early conceptual design and energy analysis. Use Revit and Green Building Studio as the design progresses for "whole building" energy analysis. Use Ecotect for more detailed analysis on parts of the design.

Put it this way: Green Building Studio helps you study how your building affects the environment. Ecotect helps you study how the environment affects your building.