Graphisoft EcoDesigner

In this review, Sid Thoo, an Australian architect and sustainability expert, takes a detailed look at the workflow of EcoDesigner, a plugin that allows the energy efficiency performance of a building model to be analyzed within the ArchiCAD environment. The review explores how the application works for quick, conceptual analysis and concludes that EcoDesigner is a valuable plugin that should be considered as mandatory for all ArchiCAD users who are serious about designing more energy efficient and sustainable buildings.


6 thoughts on “Graphisoft EcoDesigner

  1. Well done Sid!
    I have to get into EcoDesigner as we speak for a large project, and can’t wait to give it a spin. Good info on the customization option. I’ll give it a go as well.

  2. Do you have a definition for what is meant by ‘solar gain’ in the charts? It seems odd this value is highest during the winter in Perth.


  3. Hi Ian,

    Thanks for your question, and for your interest in the article.

    Solar gain refers to temperature increases due to solar radiation. Wikipedia has a good definition:

    In order to reduce the energy demand for space heating, the goal of a well-designed passive building is to maximize solar gain during winter months. The higher solar gain values you see in the EcoDesigner energy balance graph represent solar radiation entering the building through equator-facing windows and glazing. Conversely, less solar gain is more desirable in Summer in order to minimize the need for space cooling.

    I hope this answers your question.



  4. Thanks Sid,

    I’ve been looking at some typical Perth weather data that indicates January global radiation is roughly 1000W/m2 and June global radiation is around 500W/m2 on average.

    In your ‘improved’ results the solar gain around January is very small and around June very large comparatively. How has this design and its improvements managed to reject nearly all the 1000W/m2 in January and at the same time seemingly been able to absorb all the 500W/m2 in June? I appreciate lower sun angles in June will help, but such a large ‘swing’, as seen in your results, still seems excessive given the global radiation bias in the area.

    Thanks again,

  5. Hi Ian,

    Thanks again for your question. I think there are a couple of considerations that may help to answer your query.

    Firstly, I don’t think it is unreasonable to assume that correctly orientated and shaded windows can’t reject almost all solar radiation in Summer, while allowing good solar penetration in winter. This is a fundamental principle of solar passive design, and there are numerous building examples around the world that demonstrate this.

    In the improved results, the two changes I made to the model were to improve the u-value of the walls, and to improve the performance of the glazing assemblies – this I did by specifying double-glazed, low emissivity windows. The double-glazing helps to improve heat loss/gain via conduction, while the low-e glass should improve heat loss/gain via radiation.

    In Summer, where the majority of windows are appropriately orientated and shaded, there should be very little solar gain, as demonstrated by the energy balance graph. In Winter, the lower sun angles and absence of shading should mean comparably higher levels of solar gain, albeit lower than compared to standard single glazing. While I can’t claim to know all of the formulas for calculating incident solar radiations angles and the like, the results shown in the energy balance graph seem to make sense.

    On that note, I must admit that I don’t know exactly what methodology is used by VIP-Energy to calculate the impact of solar gain upon a building, other than its overall calculation results have been tested in accordance with recognized energy software protocols. I have forwarded a question to the developers regarding this.

    Also, my colleague Olivier Pennetier (he posted above), has had an in-depth look at some of the weather data files that accompany EcoDesigner. He notes that the data seems to consist of synthesized solar radiation, rather than actual recorded values. This is turn may also effect the calculation results.

    Lastly, it is important to note that with any energy analysis tool, it is impossible to predict the performance of a building with pin-point accuracy; often we are mislead in this regard, because they produce such seemingly “precise” results.

    What tools like EcoDesigner allow us to do is comparative analysis ie. If I change variable XYZ, is this likely to improve the building’s performance, or make it worse? We are then able to steer the design of the building in the right direction, and hopefully produce an otherwise better outcome.

    Kind regards,


  6. Thanks Sid, but I’m not sure I can agree with your ‘passive solar’ argument about ‘almost all’ summer gains being rejected. If you consider that solar radiation and visible light (daylight) are generally transmitted/reflected/absorbed in a similar manner. Then the ‘improved’ results would imply that you may need the lights on in the summer, but there’s abundant light in the winter.

    Sadly that’s not something I’ve come across before (I wish I had). I’ll be very interested in the response from the developers.


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