Autocad Architecture LEED EQ 8.1 update

After some positive feedback and a few constructive suggestion here is the updated LEED EQ 8.1 Daylight Factor interactive schedule that takes into account Net Area and Door/Window Assembly objects.

LEED EQ 8.1 Credit (Daylight and Views) for ACA 2008

(Real time daylight design tool for AutoCAD Architecture 2008)

In 2005 when my article on BIM and knowledge management was published, I indicated the opportunity within BIM as a methodology that has the potential to capture cumulative knowledge that aggregates within a firm and to implement the same within any BIM compliant platform.As we all understand the need to evaluate the performance of our buildings, the need for this knowledge integration is even more evident, and one avenue via which we can explore this methodology is in the integration of LEED credits compliance within the BIM model.
The Importance of LEED certification and its necessity for the creation of a sustainable built environment can be debated from several perspectives but considering the integration of real time evaluation tools should be a prerequisite for the creation of any expert system that will be used for instantaneous knowledge (code / rule) feedback.

I have to admit that, besides a few scheduling screen shots in Revit Architecture and some in articles that were relevant to AutoCAD architecture, I have not seen any serious attempt to tie in more closely any application with the concept of LEED credits take-offs or any LEED scheduling framework provided by the software manufacturers.

Now some of you could ask the question why this example is not available in Revit Architecture, and the answer to this is quite simple. I do not know how to make it work, and in this instance I will blame this on my own ignorance unless some one out there can actually explain to me why one has to calculate the area property of an room object as a result of volume by unbound height division as this, in spaces that have a sloped ceiling, will produce an unacceptable inconsistency.

So in order to have an interactive real time daylight factor analysis tool one should work with these ingredients:

Window use classification
Window style
Property Set Definition
Space style Property Set Definition
Display Theme for DF (Daylight Factor)
One not particularly customized schedule
And a few lines of VBS code slowly brewing in the background.

First we start by defining a window object classification category that defines any instance of a style as either an EXTERIOR or INTERIOR window, where only those that the user marks as EXTERIOR will contribute to the EQ8.1 calculation.

The second step is to define three different List Property Definitions whose values represent different window factors that are required for DF calculation. Those factors are:
GF – geometry factor
HF – height factor
TVmin – minimum visibility factor
TV – visibility factor

which are all dependent on window type, location and current glazing visibility as presented in this table.This method assumes that values are associated with a particular window style and in order to vary them from instance to instance one should copy and assign style in place and change the style based property definitions in order to accommodate for these variations.

On the other hand the Space Objects Property Set Definition has been modified in order to perform a required DF analysis by querying the current file for all of the windows that have matching location ID with the space objects for which the calculation is executed. The matching ID within every window object is placed within the Window Styles Property Set Definition via Location Property Definition and thereby the logical spatial link between two objects is established.

For the sake of differentiating from the OOTB Property Set Definition I decided to create two new PSD one for Window Styles and the other one for Window Objects.The object based one is labeled as 01_LEEDWindowObject and this is the one where the link to the Space Object is documented through the “WindowSpaceID” property definition while its relevance for DF calculation is established by the “001WinLocation” classification based property definition. The space based PSD is labeled as 01_LEEDWindowStyles and this is where the previously described window variables are hosted.



“LEED_GF”, “LEED_HF”, “LEED_TV” and “LEED_TVmin” are all style bound and this is where the associated space object reads the relevant values for its daylight formula.To visualize DF in real time I have included a basic Display Theme that is providing for a graphical feedback based on the calculated DF.
Tying all this together was executed within Space Objects PSD and in particular within the formula property definition that taps into two ADT libraries in order to make this work.

Set acadApp = GetObject(,"AutoCAD.Application.17.1")



Set AecBaseApplication = acadApp.GetInterfaceObject("AecX.AecArchBaseApplication.5.5")
Set SchBaseApplication = acadApp.GetInterfaceObject("AecX.AecScheduleApplication.5.5")
Set ActiveDoc = AecBaseApplication.ActiveDocument
DF_win = 0
DF = 0
PropValue_GF = 0
PropValue_HF = 0
PropValue_TV = 0
PropValue_TVmin = 0
WinArea = 0
For Each obj In ActiveDoc.ModelSpace
objName = TypeName(obj)
 If objName = "IAecWindow" Then
 Set objPropSets = SchBaseApplication.PropertySets(obj)
 Set objPropSet  = objPropSets.Item("01_LEEDWindowObjects")
 objWinLocation = objPropSet.Properties.Item("_WindowLocation").value
 objWinSpaceID = objPropSet.Properties.Item("_WindowSpaceID").value
  If objWinLocation = "EXTERIOR" and objWinSpaceID = "[ObjectID]" Then
  Set PropSets =  SchBaseApplication.PropertySets(obj.Style)
  Set PropSet  = PropSets.Item("01_LEEDWindowStyles")
  PropValue_H = objPropSet.Properties.Item("Height").value
  PropValue_W = objPropSet.Properties.Item("Width").value
  WinArea = (PropValue_H * PropValue_W) / 144
  PropValue_TV = PropSet.Properties.Item("LEED_TV").value
  PropValue_TVmin = PropSet.Properties.Item("LEED_TVmin").value
  PropValue_GF = PropSet.Properties.Item("LEED_GF").value
  PropValue_HF = PropSet.Properties.Item("LEED_HF").value
  DF_win=(WinArea/[BaseArea])*PropValue_GF*(PropValue_TV/PropValue_TVmin )*PropValue_HF
 DF = DF + DF_win
 End If
 End If
Next

RESULT = DF * 100

Without going into a lengthy discussion about what this VBS is doing, I just want to point out that the main loop is using SchBaseApplication object to access the property set of each window instance in ModelSpace object and compare its “_WindowSpaceID” property to the [ObjectID] property of the current Space Object.If the match has been confirmed within the first If statement of the outer For Each – Next loop and the examined ModelSpace object is indeed of IAecWindow type, then the second If statement is comparing “_WindowLocation” and “_WindowSpaceID” properties.
When both of these requirements are met than the set of relevant variables is accessed via SchBaseApplication object and are being channeled to DF_win formula that is being compounded within the primary loop to create the final DF value for this given Space Object.

In order to evaluate the final daylight value for a floor plan I have created a schedule that does it, but similar compounding and property extraction code could have been used to calculate the final result within a Space Object.


The prerequisites for this DF real time calculation method are the following:
ACA 2008 or ADT 2007 due to their capabilities to apply classifications to an AEC object and their use of List definitions.
This code can be retrofitted to operate within ADT 2006 and 2005 in a slightly less sophisticated way.
The code within a Space Object can not query window objects within a x-ref file and therefore both the envelope and spaces have to be part of a same construct, or a plain independent file. It is worth mentioning that the code within these customized SpaceObjects is taking a toll on ACA’s performance, but as I have tested it on a 60000 SF project with the acceptable performance the entire process can be even more streamlined during the initial design by having a zonal approach to DF evaluation.

After downloading this sample file the user should try to rescale the windows associated with their spaces and observe the change in color as the DF for this space crosses the threshold of 2%. It is worth noting that in order to create a window with the different performance values the existing style should be copied into a new style and those values should be adjusted within this new style based Property Definitions.

For any of you that have ever driven a certain French car, and you know the connotation, and especially those that were made between 1955 and 1979 by a company which I will not name but whose creation was closely connected with the architecture of Le Corbusier, you will understand my enthusiasm with this, not officially BIM like, Swiss army knife application that is still quite a useful BIM tool if you know which buttons to push. Thanks to the inspiring work of several people, like David Koch, Jimmy Bergmark, Jay Moore, Robin Capper and few others that are not yet ready to give up on the potential of embedded code within BIM compliant objects, this application proves that a good amount of intelligence can be placed behind a comprehensive BIM model.
For myself, I can not but wonder if ADSK is really listening, as I am quite sure that a few skilled programmers, and ADSK has enough of those, can crank out this code in a matter of minutes and have it become an integral part of the AutoCAD Architecture. The bigger picture is that ADSK should at least make an honest attempt to add the tools so needed in this “non BIM” application so that we can really take the full advantage of the outdated “object” technology.

This file includes all of the above described elements and I am encouraging you to test it on your own LEED projects. Being aware that there is a ton of room for improvement to this proposed code as well as that this can be far more efficient code if executed via VBA or VB, I am looking forward to get some constructive feedback.

autocad architecture