topic Re: Specific Modeling for Energy in Sustainable design

Specific Modeling for Energy

stefan — Thu, 11 May 2023 08:26:56 GMT

We are working on a series of support material for our students to use ArchiCAD as a basic BIM model for energy evaluation. However, the way the Energy Evaluation in ArchiCAD 16 works is quite specific on how you need to model...

E.g. you need to model your "heated and protected volume" using Zones that touch the internal faces of the enclosing elements.

That is a perfectly valid starting point, but our regional regulations (based on EN 13790) demand that these volumes are created using the outer faces of all elements (e.g. zones touching the exterior faces). In ArchiCAD, you can define multiple sets of Zones, e.g. on different layers, but they have some strange limitations. When I created Zones using the Walls Reference line and place the reference line on the exterior side of the building:

* The 3D representation of the zone subtracts the Walls volume from the zone.
* The scheduled Zone Net Volume is indeed net and not gross.
* Connecting or cropping zones to roofs also uses the bottom side of the roof or slab and not the top side (which I need for a gross volume). So I need to add a vertically offset roof or slab to connect to.
* Then I drew the necessary zones manually. My volume is now correct. But the outer surface is not, as e.g. the faces between the two zones is counted twice. I tried to SEO Union the zones to get the net outer surface of the volume. This does not work, alas.
* Remembering how our local Revit-using colleagues are using Mass Models for this kind of calculation (and others using SketchUp), I modified the zones into MORPH objects and made a Boolean Union of the different MORPH objects into a single all-encompassing volume. This works fine.
* However, in a schedule of the MORPH object, I could only list total surface area and volume (which is correct), but can not distinguish between individual faces. E.g. when applying different materials to faces, I can not schedule them. Making a schedule by components does not support MORPH objects.

Any hints?

Re: Specific Modeling for Energy

Laszlo Nagy — Tue, 11 Dec 2012 08:34:38 GMT

I think these are very interesting points you are making here Stefan.
I am going to forward the link to this post to the guys at Graphisoft for their consideration.

Re: Specific Modeling for Energy

Francois Swanepoel — Sat, 14 Sep 2013 09:11:25 GMT

Hi @Laszlo
I am very interested to know if ArchiCad 17 includes any specific improvements or workflows to allow for Stefan's concerns.
Here in South Africa we are eagerly waiting to see what tools or value EcoDesigner Star will offer us to help our Architects and Designers to create the required calculation reports and documentation for our projects that has to comply with our local Energy Efficiency Regulations (SANS 204 & Part XA of our National Building Regulations).
Can you give or get us an indication about the issues Stefan raised?
Regards

Re: Specific Modeling for Energy

stefan — Sat, 14 Sep 2013 10:44:35 GMT

I was told at ArchiCAD Summer School in Cardiff this month that the model EcoDesigner Star is using is incompatible with the simplified method we use in our region.

And the limitations I noted above still stand in ArchiCAD 17.

Re: Specific Modeling for Energy

Francois Swanepoel — Sat, 14 Sep 2013 11:09:12 GMT

Thank you very much for the feedback and insight Stefan

Re: Specific Modeling for Energy

Laszlo Nagy — Mon, 16 Sep 2013 12:01:04 GMT

The only improvement I can think of in this area in AC17 is that Morphs can not be scheduled by Story.
But that does not help with most of the issues Stefan originally raised.

Re: Specific Modeling for Energy

stefan — Mon, 16 Sep 2013 20:15:54 GMT

Yes, Morphs can be scheduled by floor level. But be very careful. A Morph should be positioned exactly on the floor level. 1 unit above the story level and its area is skipped. One unit below the story level and the story below gets the full area counted as well. Volumes are consistent and the logic if areas is not wrong, but don't be mistaken.