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Routledge Chats with Kjell Anderson about Design Energy Simulation for Architects

Design Energy Simulation for Architects

"While a handful of architecture firms have measured the performance of their designs and occupied buildings in the past, this is a rapidly growing trend.  Firms are simulating during design, asking for earlier engagement of energy analysts, and going back to check on completed buildings.  Performance, in this case, can refer to overall energy use, thermal comfort, daylight levels, occupant satisfaction, usage patterns, etc.  Their simulation results from early and late design are being compared against post-occupancy results, leading to a more informed design process."

1.      What led to your decision to write Design Energy Simulation?

Early energy simulation is wide-ranging and inconsistent in practice.  My impetus was to collect samples of the most important or clever uses of simulation to help give the field some scope definition.  Instead of the typical book that delves deeply into one aspect of simulation, speaking to a narrow band of users, I realized that books written for the average architect to understand and engage more meaningfully in simulation did not exist.  Even for the firms that have gotten their feet wet in simulation, some firms do daylight modeling exclusively for daylight quality or quantity, others attempt full energy simulation, others only do shading analysis.  Few firms get the full benefit of energy simulation even from their engineers for lack of an understanding of what the energy analysts are concerned with.  Within daylight simulation, even, there are a variety of techniques using computers, physical models, HDR photography, post-processing for glare, and more.  No resources I'm aware of had previously explored the breadth of useful simulations in early design, and this was an attempt to discover and catalog them.  Along with this, about half of the book was written as theory, to convey basic knowledge about energy use theory that I wish I had known several years ago, and which is necessary to inter-relate aspects of simulation.

I also realized that play is important to understand energy consequences of design decisions.  When architects meaningfully play with simulation, they begin to intuitively understand how their designs will perform.  In this sense, play can use internal or external energy modeling resources.

2.      Can you speak to the ongoing trends in architecture and design simulation? How are new developments affecting the way architects work? What are some of the current controversies that surround these developments?

While a handful of architecture firms have measured the performance of their designs and occupied buildings in the past, this is a rapidly growing trend.  Firms are simulating during design, asking for earlier engagement of energy analysts, and going back to check on completed buildings.  Performance, in this case, can refer to overall energy use, thermal comfort, daylight levels, occupant satisfaction, usage patterns, etc.  Their simulation results from early and late design are being compared against post-occupancy results, leading to a more informed design process.

Beyond firms engaging directly in simulation during design and tracking energy use after occupancy, the biggest trend within simulation is towards parametric modeling.  Parametric modeling allows designers the opportunity to explore energy use options quickly and iteratively.  The most advanced simulation techniques now allow simulation results to directly inform design by helping with interpretations. 

The caveat is that simulation should be useful: both actionable and accurate.  Simply because one has studied thousands of options parametrically doesn't mean one has set up the question correctly, or understands building science enough to have produced a useful simulation.  This is especially important with parametric modeling and solvers as the question gives shape to the answer.  All models have flaws, and only a user that understand where the flaws are likely to show up can interpret results correctly. 
Since generally the younger generation is great at simulation, and the older generation understands building science, there needs to be an ongoing conversation between the two to ensure any results are accurate and actionable.

3.      Speculating, what do you see as the future for architecture practitioners with regards to design simulation?

I'm guessing that nearly all architecture firms in the US will be using energy simulation in some form within 5 years.  Three reasons:
1. The most-overlooked part of the 2030 Challenge is that architects, using passive design techniques, are responsible for much of the remaining energy savings in new buildings.  This means that we as a profession need to understand how to design the best passive building (using a combination of experience and simulation) to avoid the necessity of running energy-sucking systems most of the time.
2. Software for non-specialist users has come along way in the last few years (ie, the post-Ecotect world), and still has a ways to go before architects can get good results consistently. Most firms on the leading edge are using the current crop of software such as Diva, Sefaira, Vasari, OpenStudio, and others.  
3. Architecture schools are teaching simulation within required curriculum, and the American Institute of Architects is also proactively engaging in the energy education of architects, helping create the baseline of knowledge necessary to approach simulation. 

4.      What do you hope readers will take away from this book?

I hope junior readers will explore how widespread and interesting the field is; I hope mid-career architects will learn to request and perform the most useful types of simulation, and I hope firm leaders will hire those young architects with simulation skills and promote this within their firms as a measureable way to achieve quality, green design.