BIM Energy Analysis with Archicad 17

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Archicad 17 As in its previous version, Archicad 17 comes with a built-in energy evaluation tool (EcoDesigner), that allows designers to develop the building energy concept from the preliminary design phase. The line that divides architectural design and energy simulation seems to be getting thinner and thinner.

On one hand, this Graphisoft approach is no doubt cutting edge. However, some large doubts remain:

How reliable are the results of this energy evaluation?

Graphisoft EcoDesigner

Last year, we wrote a long article about the new features of Archicad 16, the first version of the software to come with the EcoDesigner add-on included (before that, you had to purchase it separately).

In that article, we did not hide our mixed feelings of both enthusiasm and skepticism about this development. In the international Archicad forum, we had a chance to discuss this matter with Graphisoft developers, but some doubts remain.

The energy evaluation run by the built-in EcoDesigner add-on is not validated according to any national or international norm. Furthermore, we could not find anything to prove these results (such as a validation white paper).

Should we just trust the software?

Given how widespread the software is (Archicad) and the importance of energy efficiency, we think the time has come for us to publish a series of articles to fill in this void of relevant information. The goal of this research is to establish whether Archicad-EcoDesigner can be trusted as a reliable tool, or if it is more suited as a marketing toy, with little scientific basis.

Our concern is simple:

Unfortunately, in the "green" architecture industry, marketing is often a more diffused selling strategy than actual quality (hence the term "greenwash"). A tool such as EcoDesigner can be very useful if properly used, but it can also be very misleading if used by someone without the proper expertise. At the end of the day, the question is: who is going to use this tool? Archicad is used every day by thousands of architecture professionals with expertise in construction and BIM technology. However, what is the knowledge of these users when it comes to energy and building physics?

The addition of the energy evaluation tool in Archicad exposes the users to a risk: using a tool that probably goes beyond their current technical capabilities.

Imagine taking the best Formula One driver, and putting him/her in the cockpit of an airplane: does this seem like a good idea?

This series of articles that we are going to publish is meant to be of help for those professionals who would like to use Archicad-EcoDesigner in their daily architecture practice.

In order to do that, we are going to break down the energy evaluation into specific topics, as you can see in the following list. The goal is to understand the strengths and weaknesses of this tool. As an example, we are going to develop the evaluation of a building (in a simple box shape), with its thermal envelope meeting the passive standard.  The geometry, including any thermal bridges, are going to be run through both Archicad 17 and PHPP v7.1 (the tool for calculating a passive building).

Besides the software itself, however, we must also understand the importance of input data. Specifically, climate data and interior heat gains are of fundamental importance to estimate the energy demand of the building for both heating and for cooling. The quality of the energy evaluation is strictly bound to the validity of the input data, whatever norm your calculation refers to.

To draw another analogy, think of it as a flour mill: the resulting quality of the flour is determined by the initial quality of the cereals, whatever the machinery is.

We are going to break down our research as follows:

  • Analysis of the climate data sourced from the Strusoft server within Archicad 17
  • Default values of interior heat loads
  • Thermal conductivity of materials and transmittance calculation
  • Building systems
  • Boundary conditions
  • Overview of reference technical norms
  • Building model description
  • Zoning of the thermal model
  • Energy evaluation in Archicad 17 and PHPP
  • Conclusions

From the list, you can easily understand how complex the topic is: we'll try and explain these aspects in a way to eliminate the many doubts that surround the Archicad-EcoDesigner evaluation.

To keep up to date with the development of this research, we invite you to subscribe to our newsletter.

This series of articles only addresses the built-in version of EcoDesigner, included in Archicad 17. Graphisoft already announced a future, separate add-on, called EcoDesigner Star, to be sold separately from the base package. This new software is supposed to be validated according to ASHRAE norms, in order to be used for LEED certification. We had a chance to test the beta version of this program, but in order to issue a review article, we'll need to wait for its final version.