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leed and breeam analyses base on the same energy calculations, maybe with the exception of the imposed proprietary rules, but it's an overlay.

the results may be different, although the starting point is exactly the same. let's not get crazy about the official energy standards ūüôā


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On 7/7/2020 at 4:27 AM, gester said:

@Samuel Derenboim 

yeah, the polish certification document for the usage permit is formally standardised.


- the first page is the overall information of the building with the graphic display of its energy performance (enclosed is some older version before the tightening of the energy performance demand - the change is in the scope spread on the graphic ribbon - in this case the building doesn't comply with the requirements). the software can handle dwg imports, but not ifc models, so the calculations take approx. 90-95% of the creation time (a pretty cumbersome task, especially calculating walls and openings, depending on geographic directions), the rest is the adjustment of the installation systems. energy calculations are similar for all energy certification standards, what matters is the overall result, regarding particular requirements.


- second page is the description of the installation systems


- third page is the calculations with improvement recommendations


- the last page is the guides and notes - usually left as it is.


the certificate is valid for 10 years, and the creator is liable for any claims within this period. there's also a possibility to buy insurance for this scope, along with the professional designer's insurance.


is it somehow similar in the u.s.a.?







Our requirements have been much more rigorous as of late. There have to be areas for every fenestration and opaque wall face on the building per wall type for every floor each with their designated orientation (east, west, north, south). If we need to do something like performance values, we have to do average UA calculations for opaque wall types and total average UA calculations for total building areas in order to determine performance. The math itself is quite easy, just extracting the information out of energos and Vectorworks is the challenge.

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Presumably, if LEED is listed in the Results List of Energos as an optional analysis output, and choosing this option has Energos produce a LEED-specific analysis, which entails a different calculation method (ASHRAE 90.1 Appendix G for LEED versus PHPP for Passivhaus), then the calculation results should be different.  In reality, if one switches the Results output from Passivhaus to LEED, the calculation results do not appear to change at all as far as I could determine in running sample analyses.  But the results should be different.   NYSERDA did a comparative analysis and found that results varied significantly between ASHRAE 90.1 and PHPP modeling and simulation approaches because they use different calculation methods.  Here is a second comparative analysis that also found the two calculation methods resulted in very different results.


Given this, what is the value of selecting a LEED Results report?  How are the results indicative of what is required to meet LEED performance requirements?

If these questions cannot be answered succinctly, then is this an unfinished tool that slipped off the radar of developers?  Perhaps when the tool was launched in 2016 the intent was to build out functionality for LEED, BREEAM, and the other referenced standards in the future, so they left them as options in the Results list, but then the development never happened.  I think the tools either need to be finished properly or removed from the list, OR the documentation has to come with a sufficiently detailed explanation of the usefulness and limitations of relating Passivhaus results to ASHRAE 90.1-referenced standards like LEED. 


I do not believe it is sufficient to say that, "...Energos really is a designed energy evaluation tool that taps into the architectural design process. It's not intended for energy certification and there are other software, often mandated, doing that job. Benefit of something like Energos is that you know where you stand before that certification process because you can check the building performance and how design changes affect overall results."  Nor is it sufficient to say, "...the results may be different, although the starting point is exactly the same. let's not get crazy about the official energy standards." 


Someone who selects an estimated set of benchmark energy performance results with regard to LEED or BREEAM or any specific standard has a reasonable expectation that the results provided are actually based on the calculation methods required by that standard.  The fact that Energos is not a complete compliance tool and that it is meant for early stage design decisions is irrelevant.  If the tool gives me a "LEED Result" indicating that the design has good energy performance or bad energy performance and it turns out that that analysis is actually a Passivhaus analysis presented to me as a LEED analysis, and if I then assure the client that our preliminary LEED analysis indicates that our energy performance will be in good shape, or conversely that it is in bad shape and that we need to spend more money on additional or enhanced assemblies, when in reality I have unknowingly completed a Passivhaus analysis and the results are not at all indicative of ASHRAE 90.1 compliance, then it could lead to missed targets, missed certifications, damaged relationships, and litigation. 


To be more specific, it appears from the NYSERDA assessment that Passivhaus is more detailed in assessing the envelope, unsurprisingly, but less detailed in assessing the HVAC systems and automatic controls, also unsurprisingly.  So if I have a more or less cube-shaped, mid-sized office or educational building in a temperate climate that is internal-energy-load-dominant and Passivhaus is not fully accounting for all of those internal energy loads and associated controls, then it is possible that the Passivhaus analysis will indicate that we need to increase the performance of the envelope systems to improve the performance of the building overall when in fact this is not the case.  This could result in me spending time looking at higher performing envelope options and convincing the client to spend more on the envelope when in reality this is not the best use of resources because the loads and efficiencies are being driven more by the HVAC systems and automatic controls.  Furthermore, what is the client going to say when, for building code energy performance compliance, which uses the same calculation methods as LEED, the energy model is simulated and shows that the modeled performance is wildly different than the initial 'LEED Results' analysis?  The client could reasonably say, if the energy code requirements are based on the same calculation methods as LEED, then why is the initial energy analysis model so different than the compliance model when both models are modeling the same wall types, shape, orientation, roof types, floor types, percent/type of glazing and openings, etc.? 


Again, I think that Vectorworks needs to make a fix here.  Either remove the LEED/BREEAM options, complete them, or provide documentation to explain their specific and limited use cases.





Edited by jmanganelli
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What you say makes 100% sense. That is why i bypass the guess work and do the calculations from wall areas and other tricks with different types of geometry with records referenced in the file. However, even the areas of exterior walls are very difficult to get given different conditions of wall types and walls. Wall surface areas still cannot be calculated properly (curtainwalls in particular). I would even go so far as to say I'd be happy if VW got out of the energy modeling department, and simply fixed the current toolbase in order for the community to assemble together and make one that suits our needs. 

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Does anyone know why Vectorworks doesn’t heavily promote that IESVE has Vectorworks integration (for a long time now)?  That is pretty huge.  The only other BIM package with which it is integrated is Revit. It is arguably the most comprehensive energy analysis program available, at least in the EU and North America. 
Why not just play that up and develop lots of training for that workflow? 

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afaik the iesve is a costly application. similarly is (was?) with the ecodesigner star and its integration with archicad, where both licenses were necessary.

isn't it the case with revit and iesve?


i think that vw users are in need of a fast and reliable energy calculation tool, at best within the aplication and its price. the next step might be an integration with something bigger, but the energos level is pretty good for the designed calculations. not everyone can afford professional energy calculation applications.



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IESVE is no more expensive than the other major energy analysis tools and no more than getting into Lumion or a perpetual license of C4D.

Sefeira and cove.tools are strong options for early design.  I think for mechanical systems of moderate complexity, cove.tools can be used end to end. Now that sketchup is subscription only, there is a subscription package that includes sefaira. its an extra $1000/year over the sketchup subscription.  Not nothing but a lot less than IESVE or design builder.  I think that cove.tools is closer to IESVE’s price. 

simergy is supposed to be full-featured, like Design Builder or IESVE, but priced more like Sefaira. 

openstudio is free. 

there are many options at different price levels and a great option that is already fully integrated with Vectorworks. 

Other than revit, vectorworks is in as good a position as any other bim authoring tool with respect to energy analysis tools. 

a good path forward for more options is to go to the rhino forums and join the very small chorus of people asking for rhino.inside integration with vectorworks and let grasshopper replace marionette. Then all of the tools of the rhino/grasshopper ecosystem, including energy analysis tools ladybug/honey bee/climate studio would be available for analysis. Ladybug/honeybee are free and climate studio is closer in price to sefaira than IESVE. 

Edited by jmanganelli
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  • 7 months later...
  • 6 months later...

Not sure if this is the best spot to post this question, but here goes:  I'm learning to use ENERGOS, and hope it will help me evaluate design options.  However, I need to have confidence it's working in order to trust the results.  Which brings me to the issue...


I have a heliodon on the same layer as my spaces, walls, slabs, etc. and it's set for the project location.  It's in a temperate climate with hot, humid summers, but the results show zero cooling load.  This is consistent whether I use Basic or Advanced settings for the heating, cooling, and ventilation settings.  (A typical mechanical system for projects in the area will have cooling and heating loads that are roughly equal.)  All the walls and slabs are standard Vectorworks styles.


Thoughts?  It's a big enough error, I feel like I'm missing something obvious.



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  • Vectorworks, Inc Employee

@sixfootzero It could be a number of things - it's hard to tell like this. Have you checked U-values/R-Values of the Building elements (Doors/Windows, Walls, Slabs, Roofs)? Are you using Spaces to give you areas and volumes? 

Also under advanced set of parameters you should include the cooling system, and potentially check advanced ventilation settings to set overheating limit. Just a few things off the top of my head, let me know if it still doesn't work and it would be best if I have a look at the model in that case.

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Hi Luka, I enjoyed your tutorial on Vectorworks University!


I checked the U/R-values for the building elements, and am using spaces to generate volumes.  I clicked through all the various menus/setting I could find, but didn't see anything out of line.


I tried setting up advanced parameters, and basic ones as well.  The cooling loads are stuck at zero.


Please see the attached file.



Energos Test.vwx

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  • Vectorworks, Inc Employee

@sixfootzero I've had a look and I presume the reason for this is that your model is at a very early stage where it's essentially a really well insulated box form an energy point of view - if you create a label, it gives out A+ rating! 

There are no windows in the model, so there is no solar gain and I think between good insulation and ventilation set to mechanical, that's probably more than enough to handle cooling. There is an actual cooling energy demand value, but it's very low, which means you need very little energy over a year to keep the set comfort parameters. Load is the cooling required at hottest period and I think it probably has a value, but it's smaller than two decimal places so it's not showing.

Having said all that, if you go into advanced ventilation settings and into summer ventilation, then drop your overheating limit to say 73F, you'll start seeing cooling loads appear.

Also, when the model starts developing further and you have glazing, then solar heat gains will also come into play and it will become a more realistic scenario with cooling loads becoming a much more prominent factor.

Early stage assessment is useful for many reasons, but it's crude based on what information is provided to the model and should be taken with a good chunk of salt!

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