Sustainability Summit 2012

Autodesk hosted a Sustainability Summit on February 7, 2012. See Autodesk CEO Carl Bass in conversation with Fortune Magazine's Marc Gunther; Autodesk Sustainability Director Lynelle Cameron; and a panel of sustainable design leaders facilitated by Autodesk sustainable manufacturing lead Sarah Krasley. For more on sustainable design, visit www.autodesk.com/sustainable-design

AU Building Performance Analysis

This year's AU attention to sustainable design with the aid of Autodesk's BIM enabled applications is just another confirmation that ADSK means green business. I am particularly interested to see how far down the road we can push the information gathered through sustainability analysis during the design process into the construction activities. Some courses look very promising in that regard.
Along the same lines they just ‘up the ante’ by conducting the survey of their existing facilities from the energy footprint point of view. These results are published and posted on Autodesk’s website (Link).

Post Occupany Energy Use Analysis

Case study in usability of Ecotect Analysis for the adaptive reuse projects. More information on this project is available upon a request.

Revit - Ecotect Surface subdivision improvements

Thanks to Jon, and his post on the improved curtain wall workflow in Revit Architecture 2010, we can see how one can significantly improve geometry translation process when analyzing building's skin within Ecotect Analysis.
Keep burning that Midnight Oil Jon!

Revit Architecture 2010 gbXML improvements…

Beyond those well anticipated changes in the Revit platform such as the Ribbon Interface and the somewhat more capable Free Form modeling engine, there are a number of more minute improvements that make Revit continue to shine as the dominant BIM compliant platform in US market . In recent years Autodesk as a company has worked hard to establish itself as a champion of BIM aided sustainable design, and the acquisition of Green Building Studio and Ecotect made us all wonder how those two applications would fit within the greater agenda of building information modeling.
In the newest release of Revit Architecture 2010, certain long-overdue gbXML related enhancements have proved that good things come to those who wait. The revamped interface goes beyond a cosmetic change and introduces functionality that will definitely help building performance modeling enthusiasts.
By the same token, the new releases of Green Building Studio and Ecotect 2010 offer additional functionality via gbXML exchange that streamlines the geometry manipulation and translation process among several BIM compliant platforms.
Let’s start by reviewing the new interface, with settings that are now better exposed to the designer that would like to have a more comprehensive understanding of a proposed design’s implications on overall performance.
At the project level choices are given to determine a facility’s operational mode by selecting its category from the Building Type list which adheres to gbXML schema 0.37 and Building Type spaces as outlined in ASHRAE 90.1 2007. Another important aspect of the new interface is the ability to determine the level of detail, if you will, at which the geometry will be translated into the gbXML file.

It is important to mention that from a designer’s perspective an attempt to analyze a model at the end of the SD phase, or even later, might yield frustrating moments as one is attempts to fix inevitable “leaks” that are caused by both compounded user errors and Revit’s inability to interpret complex (rich in detail) design intent via gbXML. During this translation process Revit can ignore all of the leftover spaces that did not get a room assignment, such as wall cavities, and override them by setting the appropriate value for Sliver Space Tolerance. What is unique in the new interface is the preview of the exported model with its corresponding rooms/spaces and surfaces, in a similar fashion as with the IES export utility. The two available tabs within the gbXML export dialog box, “General” and “Details” allow for two levels of model information access as well as for some post processing of information that is submitted for the future analysis. The “Details” tab is particularly valuable as it allows for a more comprehensive look into the analytical model by allowing a user to either highlight or isolate the individual rooms as shown in pic.4 or to highlight and isolate the individual analytical surfaces for the purpose of verifying potential model drawbacks.

Switching to the Analytical Surfaces preview allows for an even greater level of detail in previewing translated geometry and in a slightly different fashion from the VRML preview where all of the surfaces are color coded, the orientation of the surface is contained in the translated name of the surface and the function of the surface is color coded. Nevertheless, beyond that almost aesthetic discrepancy, the functionality of this surface preview surpasses any of the currently available ways to validate translated geometry.
Now this is all great, but by the same token this exposes some not so great things about Revit’s modeling engine and about the ever growing lack of self imposed modeling discipline when creating content in BIM applications. As most of today’s software compensates for “sloppy” modeling, this compensation factor cannot cover up for inefficiencies within the analytical model. This leads us to another good reason for the “Less is more” approach to energy modeling. In pic.8 it can be seen how the surface tessellation that is conducted by Revit has a relatively hard time interpreting the optimal face layout for the given representation and instead of having only 4 properly oriented faces, the software interprets this wall as a combination of more than 4 faces, which translates into more analytical surfaces that are being pushed for the analysis. More surfaces do not necessarily mean a better model, but on the contrary it can produce results that are less accurate and harder to interpret.

This newly added export functionality is a significant step toward the desired interoperability between Autodesk’s BIM supporting platforms and a range of energy modeling tools that are either attributed to the same software vendor or are available as free of charge, third party Building Performance Analysis applications. One of the most obvious applications of gbXML exchange within the Autodesk family of products is model information exchange between Revit and Ecotect bundled with Green Building Studio. This somewhat convoluted way of cross application geometry and limited object information exchange will be the focus of several upcoming BIMology posts.

Green Building Studio Release 3.5

Autodesk has announced a maintenance relase of its web-based service for Building Performance Analysis that brings the following improvements;

Enable Simulation of Canadian Projects
Compatibility with Autodesk's Revit 2010 platform
Enhanced Stability
Enhanced Usability

The detailed list of improvements is available form Green Building Studio web-site.

Autodesk - Building Performance Modeling Powerhouse

After the recent acquisition of Green Building Studio, the acquisition of Ecotect is anything but a surprise. As the old saying goes, "If you can't beat them, buy them" and ADSK is apparently very good at doing so. What to expect next? Speculations aside, in my opinion another flavor of Revit might emerge, Revit Analytical as the melange of best what GBS and Ecotect can offer, Interface and DOE engine. Only time will show, but today it is quite certain who is 100% committed to BIM and BPA integration.

Green Building Studio 3.2 - The first Autodesk update

This is the first release of Green Building Studio after the recent Autodesk acquisition and it brings a few changes. The most noticeable one is tighter integration with the 2009 line of the Revit platform via the External Application addition to the Tool pull down menu.
The second update is the client application for all of the other BIM platforms that can produce gbXML files. Therefore, AutoCAD Architecture 2009 and MEP 2008 and 2009, as well as ArchiCAD users will still have to submit their files outside of their applications.
I almost forgot, black is the new green as the Green Building Studio web interface has changed to resemble the ADSK home page.

Revit Architecture 2009 to gbXML – Problematic Structure

Last week, one of the students in my course on BIM tools for sustainable design created a model that had an excess of shading surfaces and as such was rejected by Green Building Studio as invalid geometry. In order to remedy that I suggested that the same model could be processed within Revit Architecture 2009 since, as I have mentioned before, it has the ability to strip the model of excess shading surfaces. At that point this seemed like a good idea, right? Wrong. The model, which had been 4 MB in size, grew to be 48 MB in size and needless to say it was not applicable for simulation. We submitted the XML file to GBS for their analysis, and this is what they found:

	RAC 2008	RAC 2009
int.floor	232	3965
int.wall	232	305
ext.wall	376	8830
roof	3	665
raised floor	183	650
ceiling	0	2
shade	924	863
und.wall	40	2068
und.slab	33	1066
opening	1311	1457
spaces	76	86

This morning I decided to put a simple model created in RAC 2008 to the test and, since I suspected that having the structural elements might have something to do with XML output, I placed a simple round (pay attention to the word “round”) concrete column in the center of this test structure. Analysis of the 2008 XML file did not show anything unusual, so I proceeded and opened the same file in RAC 2009. Not to my surprise the newly generated 2009 file quadrupled in size and these are the findings:

	RAC 2008	RAC 2009
slab.grade	1	32
roof	1	32
ext.wall	4	36

The round column is being defined with 32 segments, and just for the future reference when modeling curvilinear geometry think of the polygon count, as even in these BIM days it still matters.

The conclusion is that the structural element is subtracted from theroom volume, the void is therefore tessellated, and surface type enumerators are assigned to the newly generated surfaces. Interestingly the enumerator for the vertical faces is the exterior wall, and this poses an alternate problem related to the overall calculated mass of the analytical model. Now, although in both versions of RAC the structural element is designated as Room Bounding, somehow RAC 2008 was semi-smart about it and it was ignoring them, where RAC 2009, possibly due to the enhancements with the room object, is quite happy in exporting those structure bound faces as well as exponentially increasing the size of the gbXML file.
In order to make previously created RAC models applicable, one should declare all of the structural elements as non Room Bounding and by simply doing this the gbXML output from RAC 2009 will be almost identical to the one from RAC 2008. This will increase the usable room area within the project, but we can all agree that this is the small price to pay for being green, or maybe not?
The only slight difference in the file size will be caused by the changed nomenclature within the 2009 generated XML file that is used for more eloquent description of exported surfaces.You can download both the 2008 and 2009 samples and their corresponding XML files by following this link.

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 “Shade” surfaceType 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.

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.

AutoCAD Architecture 2009 - Green Again!

Without making the argument whether AutoCAD Architecture is a valid BIM platform, or is just “Better for architects”, with this new release one can not but acknowledge the return of the very useful ability to export an ACA based model into gbXML format. This time, unlike with the version 2006 and prior, this is not a third party developed plug-in but is part of this version core functionality.

So why is this a big deal, or is it? Well ACA has one very peculiar object type. The e-space object is probably unlike any other ACA object, in terms of its capacity to serve as a fully customizable data container, as well as in its ability to be shaped with an ease that very closely resembles the functionality of SketchUp or the ease of Ecotect’s zones. Its geometry can be chiseled into almost any conceivable shape, but what really makes it unique in this version is the ability to assign surface enumerator types (analytical surface tags) to any bounding surfaces, including opening types, windows and doors, and export them as such for analysis to Green Building Studio.

Unfortunately, as this platform is being marketed as just a better drafting tool for those architects that still did not cross over to the other side, most e-space features are being underutilized. Their suitability for program evaluation (a minimum BIM compliancy requirement by GSA), FM required data encapsulation, and now the ability to create quick schematic design energy evaluation models places them in the category of objects that have no true competition in any of Autodesk’s offered BIM platforms. Not to exaggerate, but one can literally make e-spaces talk to the user and report any programmed relationship within the BIM model! (This example will be posted soon.)

In the next few weeks I will attempt to evaluate the quality of ACA’s 2009 gbXML file and its compliancy to gbXML schema 0.35, both in the Green Building Studio environment and hopefully with the new release of highly anticipated Ecotect 5.60 that will be able to import gbXML compliant files.
So, for anyone that wants to get their feet wet and evaluate their schematic design energy models at the early stages of their design process, the 2009 line of Autodesk architectural products is bringing some rather interesting improvements.

Autodesk - Green and Carbon Neutral !!!

It was bound to happen. Another strategic purchase by the well known giant from San Rafael. This time, like some five years ago when another acquisition redefined the software of choice for BIM from ADT to Revit, they are reinventing their commitment to sustainability by another, in my opinion even more revolutionary, move.

Starting today, Autodesk has become a major player in the arena of building performance analysis by acquiring Green Building Studio Inc. , and by doing so the “Factory” can finally stake their claim in green building beyond green marketing.

Green Building Studio, Inc. offers the only web-based solution that provides immediate whole building energy and carbon analysis on any building design scheme. Their product, based on interpretation of gbXML encoded building geometry, allows designers to share information at all stages of design.

If the quality of information contained within most “BIM compliant” datasets ever had to undergo scrutiny of its applicability for delivering better buildings, it would be hard pressed to live up to the hype. Now, the virtual representation of the physical world is one step closer to become a major part of one’s digital building, and the grammar and the vocabulary needed is what Green Building Studio brings to the house of AutoDesk.

When the late Louis Kahn metaphorized architecture as frozen music, he could not have envisioned the decades of CAD/BIM induced white noise. This move by Autodesk represents an enormous opportunity for architects to start composing in harmony with the world around us.

(read more...)

Green Building Studio and the Biofuel Use CO2 offset

If your Green Building Studio analysis suggests the potential for Biofuel use as one of the solutions for offsetting CO2 footprint, you should definitely reed this article in R&D magazine....

gbXML Project Location and Revit

Location, location, location! These days, even with the real-estate market in peril, this seller’s mantra should still be relevant for anyone that is serious about their energy modeling practice and Revit’s model translation. When exporting your model to a gbXML compliant file, according to the Revit Architecture manual, all you need is the ZIP code and the building type. Well, not quite so as unfortunately, even though the latitude and longitude data is exported to gbXML, it does not relate to the project’s zip code but to the location that is determined via the advanced model graphics settings. And since the DOE 2.2 manual clearly states that hourly loads are the function of a building’s longitude and latitude one should take that extra step of synchronizing the ZIP code and sun location within Revit before translating Revit’s building geometry. Or, we can just hope that in one of the next installments of Revit BIM platforms the sun data and energy data will be automatically synchronized. You can easily verify the inherit discrepancy that is described above by opening the newly created gbXML file and verifying the “Campus” entries of the ZIP code, longitude and latitude.

Revit to gbXML - What does the window want to be?

As I was finishing my tutorial on manually placing shade devices as part of Revit's model envelope, I stumbled across this rather interesting "feature" that was exhibited while translating geometry into the gbXML file format. But before I continue to describe that particular Revit to gbXML behavior I need to make a correction to a statement in my previous article where I was testing Revit's ability to model shading devices by using In-Place families.

"Shading devices, constructed or planted, exterior or interior, can be approximated in Revit's BIM model via the persnickety use of a variety of modeling objects, but within Revit Architecture there is no identifier that designates any such improvisation as a valid gbXML compliant Shade surface. Someone might ask, but what about using a roof or a slab family to create exterior shading devices? Sounds like a good idea, but unfortunately to export such an element, the same one should be a part of a room bounding enclosure."

I need to praise Kyle Bernhardt for pointing out that this statement needs to be revised as follows: In Revit Architecture one can use Floors or Walls (stick with generic) to represent the shading surfaces. The Walls and Floors that are of the System Family type will get exported, but if you attempt to model them as In-Place families they will be ignored.
This means that any articulated solid extrusion made as an In-Place Wall or Floor will not be exported to the gbXML file.
Nevertheless in order to successfully export the objects mimicking Shading surfaces into the gbXML file, the warning message stating that a particular Room Bounding element is ignored should be disregarded and one can proceed with saving a new gbXML file.
Now back to glazing.
In order to test the available Window families and their corresponding operational (descriptive) parameter within the Revit Building Model, place an array of different window families along one wall in a sample model in order to see if the translated output will properly identify these windows according to the Window Type identifiers that are outlined within gbXML schema version 0.34.
Those Window type identifiers are as follows:

• FixedWindow
• OperableWindow
• FixedSkylight
• OperableSkylight
• SlidingDoor
• NonSlidingDoor
• Air

When building a model, if you resort only to Window families for facade apertures it really does not make any difference what type (Casement, Fixed, Awning, Glider etc.,) is used, as all of those will be translated with the "OperableWindow" gbXML type identifier.
The opposite in this glazing interpretation is that all of the Wall Family based glazing (Curtain Walls, Storefronts) is always translated with the "FixedWindow" gbXML type identifier.

The ability to eloquently articulate glazing performance in any building submitted via gbXML for analysis can not be regarded as accurate if the designer does not have the utmost control over the ventilation character of glazed surfaces. Unfortunately, within Revit Architecture we do not have the capability to designate windows operational descriptor, which means that the Curtain Wall family based glazing will always be simulated as non operable, whilst the Window family based glazing will always be characterized as operable type glazing.

One quick way to remedy this is to identify an element's ID and use it's value to parse and edit the gbXML file before is submitted to Green Building Studio for further analysis.

To mimic the sentiment of people that are trying to use Revit Architecture for Building Performance Analysis, it is quintessential to make some functionality changes to Revit's Room Object and make it behave more like the eSpace objects in Autocad Architecture where all of the relevant gbXML type identifiers can be directly assigned to the analytical space and its bounding elements such are walls and openings.

Green Building Studio - Support Pages

For all of you using Green Building Studio's web service, a new resource describing the knows issues is available at this location.

Solar Heat Gain control in Revit's gbXML model

As some of us have ventured down the road of Building Performance Analysis (BPA) it is to clients' benefit that we fully understand that the path between BIM compliant, or want to be a compliant model and the simulation model doesn't have to be a black box. Thanks to the visionary (read common sense) approach in interpreting virtual building objects and to the creation of a standard language of building, one can regard gbXML format as the first line of defense against inaccurate modeling or translation results.

When exporting a model into an ASCII compliant XML file or examining the same model via its VRML incarnation, one can quickly validate the integrity of the model translation, or manually modify the same file with a very basic text or XML editor. This to a certain extent can compensate for the current software shortcomings or one's unwillingness to purchase another $5K software package.

Let us see what the average user can do to enhance the quality of the preliminary model interpretation, and what are the basic elements of the gbXML file that we as architects should understand in order to approach schematic design modeling with realistic expectations. To do this, knowledge of BIM compliant model structure is the key component, and reflecting on how this model is put together will yield to greater appreciation for the simplicity of its analytical counterpart. The BIM model as such, appropriately so, is distilled down to its basic analytical geometry by treating each major construction component as a 2 dimensional surface (plane) with its associated information, and this associated information is what really distinguishes the building's components in their analytical environment.

The purpose of this geometrical interpretation is the functional and data rich translation of the somewhat superfluous BIM supporting platform geometry, and to emphasize the irony of information modeling, only the spatial components and functional labels of BIM model objects are conveyed to the simulation software. So instead of true information modeling that incorporates usable physical and temporal data ,the grunt work is done after the model is submitted and from that perspective that famous "Information - Cost" BIM diagram becomes somewhat questionable.

Once we establish this common understanding of BIM's model capacity we should find a way to manipulate the purpose built model and its information after it is being exported to gbXML.
Now let's get to the very basics and learn what are the "building blocks" of a gbXML file. Not to be surprised, but the basic Euclidean surfaces are what defines the space and consecutively the building within the analytical model, and those surfaces are defined as follows within the gbXML schema;

• InteriorWall
• ExteriorWall
• Roof
• InteriorFloor
• Shade
• UndergroundWall
• UndergroundSlab
• Ceiling
• Air
• UndergroundCeiling
• RaisedFloor
• SlabOnGrade

One could ask why even mention these surface types as your BIM application can easily translate any model into a comparable gbXML file that can be sent for analysis. Therefore through a simple iterative process, the architect/designer should be able to optimize a design toward finding the most viable sustainable solution. Or is it so?

The short answer is not at all. Yes, indeed the basic building geometry focusing on slabs, roofs and walls will be generated as it defines the spatial boundary conditions, but several of the quintessential passive sustainable strategy elements get entirely neglected.

Shading devices, constructed or planted, exterior or interior, can be approximated in Revit's BIM model via the persnickety use of a variety of modeling objects, but within Revit Architecture there is no identifier that designates any such improvisation as a valid gbXML compliant Shade surface. Someone might ask, but what about using a roof or a slab family to create exterior shading devices? Sounds like a good idea, but unfortunately to export such an element, the same one should be a part of a room bounding enclosure, and besides extending slabs beyond the buildings envelope, the aperture shading definition does not comply with Revit Architecture's capacity for model translation to gbXML.

Following is the technique I use to circumvent the above described deficiency and append my own shading surfaces to the analytical model, and for its implementation a good XML editor and any VRML browser are must have tools. The editor I prefer (read free) is XML

Marker , and the VRML browser I prefer is Cortona by Parallel Graphics.

As indicated in the previous article that was dealing with the ambiguous interpretation of different glazed opening types, in this one we will also rely on the gbXML surface type and its child object opening.
In order to manually indicate the location of a shading device, it is important to locate the surface which is hosting an opening, bringing us to an interesting modeling concept in which we assume that main building elevations are perpendicular to coordinate axis substituting for sides of the world and where by the convention we assume that North is in the positive Y direction. We can certainly model any structure to reflect its true site orientation and this would not pose a particular problem, but explicitly specifying building's orientation angle is something I like to avoid at this point, especially when considering the fact that GBS can rotate the world around any structure.
So go ahead and export your Revit Architecture model and make sure that all openings are properly translated by verifying their location within the VRML file. If you adapt the translated VRML file so that it can be used within the VRML client as shown in this example, it is quite easy to identify which opening's location will be used to manually place the new shading devices.

To find the appropriate surface and the associated opening one should parse the gbXML file and look for the Surface-Opening Parent-Child pair. To verify its association with the original Revit's entity one should always compare CADObjectID value of the surface with the entity ID value in the model. Once you find this, look for the Cartesian point that determines the location of the child object in relationship to its parent.

As indicated in this code example

This same point will be used to intentionally place the shade surface in relationship to the opening object. As we are examining the opening object ,it is worth taking a second look at Revit Architecture's translation of its window families into the gbXML file as some inconsistencies will become apparent. It is always up to the user to double check the interpreted definitions and manually modify the gbXML file in order to assure for the correct window operational type translation. One major improvement to Revit's gbXML output would be the ability to to pick the appropriate gbXML type definition and have it as a parameter within the relevant family, but circumventing this problem is a topic for the next post.
Confirm the type and the location of an opening with its vertices and its parent exterior wall surface. When this is done, adding a shade object is a relatively straightforward exercise, which consists of appending desired number of shading surfaces at the end of the gbXML file and naming them incrementally as shown in the example below.
While parsing the gbXML you will notice several definitions within the surface element such are "RectangularGeometry", "PlanarGeometry", "Azimuth", "CartesianPoint", and "Tilt" where the explanations for all of them are given within the gbXML schema, and the accompanying documentation.
So whether a shade device is aligned with an opening or located relatively to an exterior wall surface, all you have to do is to identify the opening vertices within a surface or the vertices of the surface itself, and use those to locate, orient and size the corresponding shade surface.

Save your gbXML file and submit it to the GBS web site under the same project name as the original file and compare the results. You will notice that specifying windows' operability value, as well as introducing the correctly placed shading device will make a difference in the total energy picture of your project.
As I mentioned in my previous article, it might be prudent to eliminate all of the unwanted shading surfaces that are artifacts of Revit's model to gbXML translation, and then introduce a new set of deliberately placed Shading Surfaces / Devices whose syntax is described below. Make sure that you assign an unique Surface ID and associated surfaceType as "Shade".

As indicated in this code example

Unfortunately the lack of an existing native gbXML editor makes this process labor intensive but the insight into the future performance of a new design, in my opinion, makes this entire exercise quite valuable.

SketchUp goes Green

Greenspace research has just release a new beta version of Demeter plug-in that expands the benefits of using Google SketchUp for preliminary design process. This plug-in provides the ability to perform the early energy design analysis within minutes, as well as the ability to import and export the gbXML files.
Some of the features are:

• Properties assignable to surfaces
• Enclosed space identification
• Boundary surfaces assignment
• Contiguity checking
• Integration with USA and UK version of Green Building Studio (This is BIG!!!)
• Import and export of gbXML files
• Direct export of SketchUp model for the Whole Building Energy analysis

The only question that remains to be answered in whether we are witnessing the rise of low cost BIM application and how effective is this more than welcome integration with Building Performance Analysis software.

Green Building Studio 3.0 - Released

The Green Building Studio has recently announced the release of GBS Version 3.0. This new version is designed for architects to use on all their design schemes on each project to ensure every building they are designing is carbon neutral ready. Exciting new features include:

• Carbon Neutral Building Check – Automatically estimates the feasibility for each building to achieve carbon neutral status using local grid emission data. US EPA ENERGY STAR Score – Computing each building's US EPA ENERGY STAR score or Architecture 2030's targets.
• Water Use Analysis - Estimates the water needs, savings associated with efficiency measures, rain capture potential, and LEED credits for the building.
• Daylighting with Energy Savings – Automatically determines LEED Daylight Credit and room by room glaze factor analysis.
• Natural Ventilation Potential – Automatically determines if the building location and loads are well suited for naturally ventilating the building.
• Local Weather Data – Providing access to over 50,000 weather locations, ensuring the design team uses local hourly weather data within 9 miles (14km) of your building rather than selecting from the typical 230 airport locations.
• Onsite Renewable Energy – Automatically analyze every exterior surface to determine all the best performing photovoltaic surfaces. Discover annual energy generated for your building from a wind turbine.
• Corporate Accounts – Providing firm-wide management of users, building designs, building templates, and review of corporate wide CO2 emission, energy and water use analyses. Leverage key staff on every project no matter which office they are in.
• Passes Industry Standards – ANSI/ASHRAE Standard 140-2004, Qualified Software for Energy Policy Act of 2005, & Microsoft Platform Test for Hosted Solutions (Platform test was conducted independently by VeriTest).

See the video, which demonstrates how to design a building to be carbon neutral in five minutes using GBS Version 3.0!