Monday, March 31, 2008

Revit 2009 - Smart about shading surfaces

The Revit 2009 line of products offers some rather nice improvements in regard to the structure of the gbXML file, as well as in regard to how the geometry is translated into the same.
The first visible improvement starts with Energy Data entry within RAC 2009 Project Information options. The user will have the option to define the ground plane location and project phase as well as the “Sliver” tolerance, which specifies the tolerance for areas that will be considered sliver spaces.
But to me the most interesting one is the ability to specify whether the exported analytical model will contain "Shade" surfacesTypes enumerators or not. If the decision is made to export the model without Shade surfaces, the resulting gbXML file will represent pure space/volume analytical geometry, stripped of any intended or unintended "Shade" surfaces.

In the case that you really don’t care whether the addition of "Shade" surfaces will offset your results, go ahead and turn on the "Shading Surfaces" option, and voila, they are back whether you like them or not. This opens the possibility of manually merging the non "Shading Surfaces" model with only those shading surfaces that are welcome in your analysis, like eaves , overhangs, and various tectonic elements that will impact the insolation loads.
The following workflow describes one possible way of merging both gbXML files by using GBS’s VRML browser and a suitable XML editor like XML Marker.

Export two gbXML files: one with "Shade" surfaces turned off and one with "Shade" Surfaces turned on.
Submit the one with "Shade" surfaces to GBS and look at it in the VRML viewer. Examine the surfaces whose name contains “depx” as part of their description and this will help you identify those that you are willing to keep.

Once those surfaces are identified, in the XML editor open the file containing "Shade" surface, copy the entire surface(s) definition, and paste them by appending those after the last element definition in the gbXML file that does not contain any of the “ShadesurfaceType enumerators. Save the modified file and compare the results.

If you work with a relatively small building these results will not be noticeable, but as the scope increases and the complexity of the structure increases, as well as the need to switch from generic building elements to those that have real world thickness, the difference between these different Shading Surfaces options will become more evident.

Monday, March 24, 2008

Smarter and Greener BIM with ACA 2009

This article might be offensive to those that are fundamentally opposed to the idea of using ACA as a BIM supporting platform, but nevertheless I cannot withhold my enthusiasm for the improvements that have been made with this new and somewhat downplayed release of 2009.

Before I explain the above statement let us for a second focus on the recent publication “BIM Handbook” by Eastman, Teicholz, Sacks and Liston, in which the authors are somewhat specific in outlining the basic minimum requirements that any BIM platform should meet.
According to the authors, the only key point that does not qualify ACA as a BIM tool is presented by this sentence; “Models that allow changes to dimensions in one view that are not automatically reflected in other views”.
To put the above statement into perspective, it might be prudent when discussing BIM to put the emphasis on the information associated with the building process, and on a given platform’s ability to link and mediate access to different information resources, manipulate it in a way that can be, but it does not have to be, object driven and report it in a way that can be either dictated by the future national standard or by a particular project’s requirements.

Personally I have always been drawn to more pragmatic and budget minded interpretations like this one: “BIM is about creating a richer set of project information, about understanding and being able to recall as much of the project as necessary to allow better informed design decision”, Davies 2006.
So what does this have to do with ACA? Well when it comes to information, it is hard to beat this Swiss Army knife of an application, and if Autodesk really thinks that “AutoCAD Architecture is better for architects”, this release will prove this more so than any other in the last 5 years, but to see this one should look behind the scenes, ribbons, endcaps and few other more in your face changes.
With this release think about interoperability, GSA standard project delivery and Carbon Footprint and than take a deep breath of relief, as the ACA team has finally got it.

Let start with the concept of green-washing as it applies to all of those applications whose claims fell short of promises, but not this time and not with ACA 2009.
With ACA 2009 the architect is empowered again as BIM platform has the ability to specify space loads, occupancy, conditions and thermal properties of the envelope. Than one could say so what? What I say! How about being able to deliver this information via gbXML file for analysis in Green Building Studio (recently purchased by Autodesk) or to the upcoming new release of Ecotect. Needless to say, all of it has been accomplished via the clever use of Property Set Definitions, as many of us have been suggesting for quite some time.

Yes, there are other BIM platforms that can deliver this, but then you need to start thinking about a discipline specific platform and another $5000 out of your pocket.
Enough about green: let’s move to BIM standards, and the way the most influential client on the US market defines them. If understanding the minimum BIM compliant project requirements imposed by GSA will ever help you in taking care of your insomnia, go here, but in the meantime the future user of ACA 2009 can peacefully rest knowing that its product has a GSA compliant template with all of the spatial and programmatic classifications built in it.

And, as if this was not enough, the ACA team had to prove how well they can listen and they have linked the object classification and IFC Pset(s) to the IFC Export feature, enabling users to classify ACA objects as IFC compliant classes and associate them with their IFC compliant properties. This means that my Laboratory Casework Library that is made of Doors and Curtain walls can be correctly translated into IFC format and imported and recognized as Furniture with its IFC compliant properties.

Briefly describing these several features does not do any justice to the significance of these quiet changes introduced by the new 2009 release of ACA. In my view it represents a paradigm shift with respect to imaginative handling of objects information and in all honesty extends the shelf life of this platform in ever changing and redefining BIM times. Schematic design in ACA and the related Building Performance Analysis and interoperability are a move in the right direction with the clear goal to award any practitioner that believes in BIM’s well publicized cost/effect curve.

Wednesday, March 12, 2008

Illinois Tool Works Acquires hsbCAD

"By bringing together Ameri-CAD's VisionREZ software to anchor the architectural front end in combination with hsbCAD's strength in structural modeling, detailing and manufacturing, ITW has created a solid platform that will unite the fragmented residential design market."
(VisonREZ news letter)
This is an exciting news for everyone that regards AutoCAD Architecture as a viable BIM platform. hsbCAD brings an amazing palette of software solutions built on AutoCAD Architecture that will, with no doubt, enrich VisonREZ's path toward an integrated BIM solution.

Tuesday, March 11, 2008

Greener Photovoltaics

BioSolar, Inc. is developing a breakthrough technology to produce bio-based materials from renewable plant sources that will reduce the cost per watt of solar cells. Most of the solar industry is focused on photovoltaic efficiency to reduce cost. BioSolar is the first company to introduce a new dimension of cost reduction by replacing petroleum-based plastic solar cell components with durable bio-based components.
(read more)