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Include Acad LT for that matter. Just need to know how to define blocks,
attributes and extract them, and automate Acad using scripts (*.scr) files.
Acad LT is definitely programmable if you know how to generate *.scr files,
start acad with a script, and otherwise read attribute extract files, or
process DXF files. Just depends how much effort wish to put into the task.

As for 2D/3D. Acad LT can be used to create wireframes, which can be
exported for input to frame analysis programs, where they can be rendered
for better visualization. I have occasionally drawn 3D wireframes, with
hatching to planes to give some semblance of solidity, to illustrate
problems I have identified using 2D but no one else otherwise comprehended.

So 3D is not necessary to identify and recognize problems, having a habit of
always drawing 3 orthographic views and visualizing sections millimeter by
millimeter helps identify problems. Only the different sections need to be
drawn and it doesn't take too long to draw in Acad LT. The real requirement
is that a human designer takes an interest and asks questions of the
proposal and seeks answers.

So a 3D model may save time, and reduce transcription errors (mark numbers
on plan not matching mark numbers on elevations etc.), since have a single
object which  can be viewed from any direction and consistently identified.
It is also useful to illustrate problems to those who cannot understand
technical drawings.

The main benefit of BIM is the use of IFC (industry foundation classes) and
CIS/CIMsteel and STEP standards to represent the data that needs to be
maintained and transferred from one application to another.

But if not working with other parties that need information as computer
data, then can create own BIM using simpler customized data "structures"
more suited to your specific needs.

So using Excel/VBA or Access/VBA, or WSH (VBSrcipt or Jscript) can get data
in and out of CAD packages like Acad LT or if wish to invest in high level
programming language use Delphi or C++, there are also free programming
languages available on the net along with information and sample code for
STEP. The only problem with scripts is that they cannot interact with Acad
or Acad LT, but if the purpose is automation, then interaction with Acad is
not necessary.

If need to interact, then COM compliant packages like Acad, IntelliCAD,
TurboCAD and even DesignCAD, provide even more potential for  developing a
simple BIM.  For that matter could even consider using frame analysis
software like Multiframe for developing a simple structural BIM.

But as I say it all depends on how easy and interested you are in computer
programming, and developing appropriate data structures for your purposes
and how repetitive what you do is to make it worth the effort.

My view is I can spend say half an hour with pencil and paper each and every
time I do something, or I can spend 5 hours programming the computer, and
turn each future repetition into a 5 minute task (Accepted such opportunity
not always available. And expensive if employing someone to do it.). Each
program can be built upon and so programming time decreases. I may not have
the sophisticated systems of the big commercial players, but having
developed my own source code, and having such source I can effectively do
what ever I want with the data and function libraries available to me. (eg.
Commercial software may be slow to update to new codes, or code errata. And
such software may have one way of doing things which may become a hindrance
on certain projects, requiring translation of problem to match software.
Software is just a tool: I've used structural analysis software to renumber
nodes and pipes in hydraulic networks. Its just data, the computer doesn't

Its not all that difficult to extract parameters from calculations in Excel
and then generate scripts which draw details in Acad. And since Excel
contains the data in the first place there is no need to retrieve it from
Acad, unless have to manually modify details in Acad: in which case just
severed the relationship between calculations and detail.

Basically a commercial BIM package provides a single user interface to a
single data model, to do all the things you would normally do and are
capable of doing, one way or another, and traditionally would have done with
pencil and paper. The next generation is 4D, the timing and staging of
fabrication and construction. You have the building but when and how do you
gain access to the site? Where is the steel and concrete, and labour coming
from and when?

In essence the building and construction industry is slowly catching up,
computer wise with manufacturing and using acronyms to describe what
everybody has always done but now possible or otherwise done by computer:
CAM, CIM, CAPM, MRP I / MRP II. At present the full benefits only appear to
be available for steel and timber, where CNC code is generated from the data
models and sent to machine tools. (How often have you watched a glaring
error come off the plotter? In other areas of manufacturing they use
re-useable machining wax, before expensive steel is wasted. Or CAD software
which turns CNC code back into CAD model. How is the CNC code generated for
a CNC beam line checked?)

Before buying the latest acronym I recommend completing a thorough review of
how effectively you are using your existing design and analysis tools.
Chances are that some minor changes to how you "structure" your data and
projects, can have a significant improvement on productivity. In the long
term may still end up buying the commercial BIM, but will have a better
understanding of how unsophisticated the software really is (lots of little
programs ran from a single interface: sounds like windows), and will be
better placed to define what information you want and how you want to work
with such data. It's a design and analysis task.

Happy to stay with Acad LT 2000, until someone can show me how to half my
input time and double my output: it has to be an immediate improvement. (We
can all improve productivity daily without the expense of purchasing new
tools. NB: it takes less than 1 minute to generate simple framing plans and
elevations (stick diagrams), using scripts.)

With COM (common object model) Automation Excel can be the central data
repository and controller for all your other applications. Whilst the BIM is
going to collect the data in a graphical model, and export tables to Excel. 

Now where did the idea for that building start? Was it visual or far more

Conrad Harrison
B.Tech (mfg & mech), MIIE, gradTIEAust
South Australia

-----Original Message-----
From: Thor Tandy [mailto:vicpeng(--nospam--at)] 
Sent: Monday, 2 July 2007 02:58
To: seaint(--nospam--at)
Subject: RE: REVIT

Include VectorWorks in that too ...

Thor A. Tandy P.Eng, MIStructE, Struct Eng
Victoria, BC

-----Original Message-----
From: Dennis Wish [mailto:dennis.wish(--nospam--at)]
Sent: June 30, 2007 10:42 PM
To: seaint(--nospam--at)
Subject: RE: REVIT

I suppose that it is possible to modify AutoCAD Architecture 2008 to become
a BIM s............................................

I don't see the advantage to REVIT other than it creates very nice 3D views
supposedly as it actually looks, but in reality, I don't detail in 3D - I
detail in 2D so that it is very clear as to what I want constructed. 3D
helps me to identify conflicts in elevation where members converge off their
mark. In many cases the designer does not consider the needed space for
structural members and this becomes clear in 3D since you can show your
client how two roofs may or may not converge properly.

I also think we should be spending more time creating professional standards
to simplify the cross-platform compatibility between offices. This is
difficult, but if we don't work on then then it does not matter how uses
REVIT, AutoCAD, DataCAD, or any of the many CAD packages out there. The
negative side to all of this is the failure of Autodesk to accept a DWG
standard since they attempt to create a proprietary change with each years
new version. The DWG Alliance is failing since they were sued by Autodesk
who won the suit to protect their DWG format in court. I think this is a
setback for the Architecture and Engineering professions. We will all have
our favorite tools, but without a standard, our jobs become more complicated
working with new clients using different versions of the same or various
other CAD packages. DXF is not a standard that is worthwhile. Autodesk has
little to fear from allowing DWG to become a cross-platform standard since
the future of the software lies in the creation of new productivity tools
rather than protecting a drawing standard.

My $0.02 worth.

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