The Global Archicad Community

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Hello Andyro

Thank you for that link to the blog, very detailed, I have not used or even looked the Energy model review in' AC. As you wrote graphisoft and passivhaus should get together, the designPH (in a good direction if you dont use BIM software for your work). They should really just eliminate the designPH and BIM2PH and just have it right in AC or at least an add on, something that we wouldn't have to guess are the numbers correct.

[JamesLEDA2]

While I can't speak for Graphisoft, the detailed consideration for vertical (by structure) thermal bridges and lateral (psi) thermal bridge simulation and addition of length parameters (you model every lateral detail, and provide a length multiplier in the structures list view), as well as window installation psi values, appears that EcoDesigner's developers were in fact aiming to align 100% with PHPP. In fact I wrote a blog on this here: https://www.thomsonarchitecture.ca/2020 ... ive-house/

I have yet to complete my PHPP course of study and exam, but it seems GS is 90% of the way towards a completed tool. The PHPP export works (tested to 9.6) but is partial, and Exterior Envelope Area needs to be calculated in 2 ways, for its own calculation methods, but also for PHPP export. This could considerably reduce the PHPP input process if export was consistent and reliable, not to mention well documented.

Andy, I completely agree that it would reduce a lot of input (not 90% however, there is significant input required regarding the shading and heating, I've not checked U-Value and thermal conductivities of elements) however, one of the main reasons that PH is a safer standard is because it uses external dimensions, thus over estimating the heat loss. then, by calculating areas externally, the thermal bridge PSI values tend to be negative, which is essentially a correction factor for overlapping elements.
Due to this methodology not being followed by Graphisoft, it makes the PHPP not valid and requiring complete recalculation manually or by another means.

I REALLY wish Graphisoft would either resolve this, or ever reach out to some PH professionals (THIS IS ME OFFERING MY SERVICES) to make this work as it's so close, better than having to remodel in Sketchup (in designPH) and would make it so much easier for designers to understand how their designs are likely to perform.

EDIT: I'm now reading through your blog post with glee. You've obviously used ED more than myself (being a lowly AC Solo user) and having the frustrating time limits of a very small practice. I'm hoping to get some time in experimenting the ED properly whilst working through your blog post in a hope that it provides some useful insight.
THANK YOU

[JamesLEDA2]

I've actually had a thought, if we produce a BEM model, with an external skin marking the boundary of the thermal element and have a way of setting a graphic override or structural view to hide all layers of an element internal of this external skin, the zones could be updated to account for this and represent the building model correctly as per the PHPP. OR you could also just draw the defining line in 2d and use this to define your zones for PHPP purposes however, this would only work for walls and the roof and slab would need to be defined another way.

[JamesLEDA2]

A couple of things that seem to be missing from your overview from my very brief tests this afternoon are...
the double counting of openings previously mentioned in this thread. Wall areas are exported with the opening area already removed into phpp, then in phpp, the opening areas are again subtracted.
Also, in my test the exterior door is not calculated correctly, I cannot work this one out, manual measurement gives me 1.89m2 but the exported value to PHPP is 2.11m2