This final post follows on from:
This will serve as a few added points and a bit of a conclusion:
I was speaking to Elrond Burrell following the first posts and we made a few observations:
• Units are an interesting problem in that the US has a pound/inch version of PHPP as well as the metric version; also the settings for Conductivity in Vectoworks Energos are as R values rather than U values. This is straightforward to change as there are online calculators that can sort this (SEE HERE):
• You don’t need to export from SketchUp DesignPH until the last minute as the software’s dashboard has enough information to check the design and compliance:
nb Screengrab from version 1.0; Current versions are v1.0.30 for PHPP8 users and v.1.1.50 for PHPP9. Updates (with required log-in available at (opens in new window): http://www.designph.org/patches_updates
You then export from DesignPH to PHPP when you want to add additional information or for Certification
• We were wondering how many people were actually using Sketchup DesignPH ‘on real projects’ and Patrick Osborne informed us that his Practice “Found it very useful for complex refurbishmentss (making sure all thermal elements are counted!)”.
DesignPH is also featured in ‘PHPP Illustrated’ by Sarah Lewis (Available HERE from RIBA Bookshop).
• I’ve tried doing comparisons between PHPP results and those from Vectorworks Energos but they are tricky as everything is handled in slightly different ways; window shading is just one example. This is a key advantage of DesignPH in that it was written by the Passive House Institute specifically to integrate fully with PHPP. I may return to this at a later date but the writers of Energos are adamant (as I’ve queried it) that the results are hitting Passivhaus results exactly.
Comments as always welcome…
Comment below from David Edwards (software developer of DesignPH):
“One of the most significant changes between the initial release designPH 1.0 and the current versions is the shading reduction factor. In designPH v1.0 shading objects were automatically detected in SketchUp but the dimensions of shading objects were exported only to PHPP and did not affect the designPH calculation. The shading reduction factor is now calculated directly within designPH, which gives a greater parity between the preliminary results calculated by designPH and those obtained after exporting to PHPP. As far as I could tell from my own investigations, Energos offers no comparable feature – shading factors must be manually entered and surrounding buildings in the 3D model have no effect on the energy balance. [Editor’s Note: This is correct]
Another key difference I found between Energos and designPH/PHPP is that it is very difficult to interpret the results in Energos – there is very little breakdown of how the final energy balance is arrived at, whereas in designPH/PHPP the calculations are more or less completely transparent. I also found it difficult to verify if the thermal envelope was fully accounted for in Energos, whereas designPH gives direct visual feedback by the red / brown colouring of the surfaces when thermal area groups are assigned. I also found in Energos that it is quite difficult to know, and have control over, exactly which surface areas are taken as the external heat loss surface, when you have junction between different elements.
It should also be noted that although VectorWorks Energos provides the 15 kWh/m2a specific annual space heat demand as a target metric in accordance with the Passivhaus certification criteria, Energos alone cannot be used for certification of Passivhaus buildings according to the PHI criteria. Therefore in that respect, both designPH and Energos have the same status – they are both preliminary design tools that give direct feedback on the energy performance of the design from a 3D model, but a PHPP model is still required in both cases if the design is to be thoroughly tested and certification is to be done.”
Can we work together?
If you are looking for an architect with Passive House (Passivhaus) Certified Accreditation (Designer / Consultant) or if you are another architect/PH Consultant/Designer (in the UK, Ireland or even further afield (I’ve been called as far as the Virgin islands previously)) and would like us to work together on your project(s) (ideally using Vectorworks) then please do not hesitate to CONTACT US…