How Energy Modeling Will Impact the Design Process

How Energy Modeling Will Impact the Design Process

It’s a topic that cannot be avoided for any longer. The ongoing Paris Climate Conference has seen an unprecedented amount of participation - even before the summit began, over 150 countries submitted national plans of action to the United Nations - and there seems to now be a global consensus that we must cut back on our energy use and reliance on carbon polluting fossil fuels, or risk causing irreversible damage to our planet. By the end of the conference, an agreement will likely outline energy-reducing strategies by which all countries must abide. For architects, this means fundamentally changing the ways we design buildings and determine their success. Traditional building and construction methods consume large quantities of natural resources and account for a significant portion of the greenhouse gas emissions that affect climate change. In the United States, the building sector accounts for 41 percent of the country’s energy usage, according to the U.S. Green Building Council.

But this information is hardly new, and thankfully, our profession has been preparing for this change for some time. In 2006, the American Institute of Architects became the first adopters of the 2030 challenge, a call for all new buildings, developments, and major renovations to reach carbon-neutrality by 2030, with milestone goals of reduced dependence at 10-year intervals along the way. Each year, the AIA releases a progress report outlining the current standing of energy consumptions and take-aways from their findings. This year’s key conclusion? We must start integrating energy modeling techniques earlier into the design process.

The Bullitt Center was designed with energy modeling software. Image Courtesy of Bullitt Center

The report found that projects using energy modeling software in 2014 met or exceeded the 60% energy reduction target 26% of the time, with an additional 25% of projects coming close. In contrast, only a few outlier projects built without energy modeling reached the challenge goal, and the 75th percentile of non-modeled projects landed behind the 50th percentile of modeled projects in energy efficiency. While the benefits of adopting energy modeling are clear, just 44.2% of projects integrate energy modeling in the concept or schematic phase, a statistic the AIA calls a “missed opportunity.” They continue, “having a model in place at a project’s outset helps ensure that design teams will keep working on energy reduction throughout a project’s twists and turns. Without a model at the start, it’s too easy for energy issues to get short shrift as a project changes.”

The AIA’s message is clear, and the report seems to freely suggest that a building’s form should at the least be informed by energy saving calculations, if not fully determined by them. This leads to the question: How does integrating energy modeling into the design process affect the designed product?

Bloomberg Center Exterior Rendering. Image Courtesy of Morphosis Architects

One place to start looking for the answer is in buildings already being designed with this technology. For their design at Cornell University’s Bloomberg Center on Roosevelt Island in New York, Morphosis Architects and engineering firm Arup are using energy modeling software to aim for a net zero rating. Morphosis principal Ung Joo Scott Lee described how their design process was impacted by the energy restrictions:

“From the beginning, we knew that we had to tackle the PV surface area issue. PVs are becoming more efficient, but they’re reaching an efficiency plateau, so we have to deal with the horizontal surface. That translated into a building that had a particular form, a certain type of massing.”

Another place to look is in the capabilities of the software itself. According to the AIA’s report, the most commonly used tool is Sefaira, a graphic daylight-simulating plug-in for 3D modeling programs such as Revit and SketchUp that recently added energy analysis engine EnergyPlus to allow users to see energy information displayed directly on an architectural model. Similar programs include Vabi, Green Building Studio, IES Virtual Environment for Architects, DesignerBuilder, Open Studio, IESVE, eQuest, Trace 700 (for HVAC systems), Trynsys (for solar design) and Graphisoft EcoDesigner Star, an extension for ArchiCAD.

Courtesy of Sefaira

Architects are largely visual learners, and if architects build models using these graphically-driven software packages, they will be much more likely to end up with an efficient, artistically-pleasing design, than they would if they attempt to retrofit a form to become more energy efficient. Depending on which software is chosen, different characteristics may be displayed with heightened graphic importance. For example, designing with daylighting information displayed may result in buildings with priority placed on solar orientation, while drawing with thermal data turned on could change a building’s selected materials. Ideally, an architect considers all of these conditions but if, as the AIA suggests, we are to start using energy modeling from a project's inception, the initial design response may still be influenced by what information the software is giving you and how it is displayed.

A large portion of the energy saving techniques employed in buildings involve reducing reliance on mechanical systems for lighting and climate control. The more natural light in a space, the less users need to rely on energy draining artificial light sources; the more comfortable the air temperature and quality, the less mechanically controlled air is necessary. The different elements of a building’s design can be adjusted to allow for optimization of these passive strategies. But energy efficiency can also be a result of the building user’s actions. Leaving a window open during the winter or leaving unused appliances turned on for extended periods can cause energy losses. Does meeting energy quotas mean that we should lean towards creating stable, non-interactive environments via inoperable windows, automatic window blinds, etc.? These are techniques that don’t necessarily make a building more efficient, but are used to make a project’s energy use more predictable and quantifiable. As detractors of the LEED system have pointed out, meeting numbers provided on a checklist can lead to the loss of innovation in sustainable design. This same effect could occur with the use of energy modeling software. Software programs can only recognize techniques currently employed to reduce energy reliance, and working and building in this software encourages designers to use these established strategies rather than thinking from a wider perspective.

Sustainable Strategies used at The Bullitt Center. Image Courtesy of Bullitt Center

Perhaps in many projects, energy design would be easier to understand if energy were treated more like money - projects begin with a limited energy budget, and designers must choose the important parts of the project to dip further into the budget. There is an artistry in choosing the right places to spend money - perhaps the same can be true of spending energy. This approach was also utilized in Morphosis Architects' Bloomberg Center, where large glazed areas were placed to take advantage of views to the Manhattan skyline, despite slight losses to the building’s energy efficiency. The design prioritizes concept in key areas while prioritizing energy efficiency in others. Energy modeling software allows them to make those decisions while remaining within the project’s overall energy budget.

But using an "energy budget" in this manner should not be the mandated strategy for every building project. Energy software evaluates a building using a codified criteria, but overall sustainability can be something that is more than a set of numbers, and innovation is spawned when a problem is approached from a variety of directions. Today, the energy reductions required for new buildings are still technically difficult to achieve, but people are no longer impressed by making energy reduction the raison d'etre of the work - as they once were in projects such as Ken Yeang's Menara Mesiniaga project, for example - perhaps because such projects today generally settle for established techniques rather than exploring the possibilities of sustainability. While it will soon be imperative that buildings reach high levels of efficiency using energy modeling, there should still be room for buildings that reach greater heights of sustainability through new techniques. By using energy modeling to set a new sustainability standard in more everyday buildings, perhaps architects will be driven to reach greater levels of innovation when they decide to make pushing beyond software capabilities the project’s main concern.

Until recently, there has been a dichotomy between artistic design and sustainable strategy. But we have now entered an era where that gap can be bridged. With the current global attitude toward environmental sustainability and the AIA’s recent report on 2030 challenge progress, it is clear that energy design must become an essential part of the design process. The latest energy modeling software should allow architects to design with new metrics in mind, but not in the way, a distinction that is crucial for the success of the program. Because for energy modeling to be valued as something to be worthy of “capital A” Architecture, architects need to know that it will not come at the expense of the conceptual value of the work.

About this author
Cite: Patrick Lynch. "How Energy Modeling Will Impact the Design Process" 08 Dec 2015. ArchDaily. Accessed . <> ISSN 0719-8884

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