Spreadsheet Sustainability

Visionaries may talk up instant output and 3-D digital models for complex projects, but the bulk of analysis begins and ends with by-the-numbers spreadsheets.
This course is no longer active
[ Page 4 of 4 ]  previous page Page 1 Page 2 Page 3 Page 4
From GreenSource
Russell Fortmeyer

The Future of Real-Time Modeling

While the energy-systems planning of CTG and the building-systems optimization of Buro Happold represent examples of the upper end of the industry's capability in multi-criteria modeling, the online chatter in architectural modeling forums focuses on connecting these environmental performance processes with formal modeling in programs like Rhino, Autodesk's Revit visualization tool, and Bentley Systems's optimization software, Generative Components. The agenda is less about replacing deep systems interrogation by professionals and more about making the early design phase of a project more robustly attuned to environmental inputs when there is still time to change the architecture in significant ways. Andrew Payne, the founder of Lift Architects and more recently a doctoral student at the Harvard Graduate School of Design, has cowritten a program, Firefly, that links real-time controls information directly into a digital architecture model through the Grasshopper platform. You can download Firefly's beta version for free. In turn, Grasshopper can be used to program parametric models that can directly influence architectural form in Rhino. In theory, Firefly could allow you to take real-time wind data from an online weather station feed and then generate an unlimited number of corresponding facades; an optimization algorithm could parse through these alternatives to find the best fit given a set of predetermined constraints. Given 15-minute intervals between wind readings, you would end up with the 15-minute facade. If it sounds neat, Payne is inclined to agree.

"This is really a prototyping platform to get ideas out quickly," Payne says. He often taps into a website called Pachube (www.pachube.com), which links to any publicly reported sensor and illustrates them on a map of the world. You can find things like electricity consumption, temperature readings, and the output of a solar photovoltaic array, all reported in real time. Although consultants like CTG's Meacham rely on historical data from several years to minimize anomalies and establish reasonable averages, a real-time modeling approach could benefit projects or systems being designed to plug into an existing infrastructure. A simulation of proposed wind turbines could then be embedded in a digital model. The model incorporates the real-time energy consumption of an existing neighborhood to understand the fluctuations in the turbine's interface with the grid over a week of real-time modeling. Given enough computing power, you can see how this simple platform could easily scale up.

"This is not going to beat BIM at being BIM," says Payne. "But it is the first time we've embedded this real-time information into a CAD package." Since the Grasshopper beta version is open source (and free to download), there are several concurrent efforts to Firefly aimed at connecting environmental simulation and data into an algorithmic model to inform architecture. Christoph Reinhart, an associate professor at Harvard's GSD and Payne's doctoral advisor, is developing a program called Diva, which would integrate Radiance and Daysim-two daylighting programs-into Grasshopper to then manipulate a Rhino model. Efforts are also under way to integrate Autodesk's Ecotect program into Grasshopper, although Ecotect has already been integrated with the Generative Components algorithmic software. To the non-aficionado, this software interoperability arms race can quickly become confusing. And there is a tendency for the majority of users at this level of design to prefer open source software or those that remain in the public domain. "The power of Grasshopper lies in the fact people with no computer programming background can get up and running creating very complex things in a matter of hours," says Payne. "The promise is a new way of thinking about design."

What anyone who works in this field will tell you-grand public pronouncements aside-is that a fully integrated software package that takes into account energy, water, daylighting, waste, greenhouse gases, etc., is several years, if not a good decade, away. "There is a lot of time involved in going back and forth between software," says Buro Happold's Williams. And CTG's Meacham emphasizes the need to have tools that can be demonstrated in face-to-face project meetings. "With Excel, we can look at trade-offs in real time so the whole project team can see results and make meaningful decisions that can actually be implemented," he says. So, maybe it's safe to say, regardless of the software packages that eventually come to market, they will likely remain attuned to concept-level design, not the nuts and bolts of hardcore engineering. For that, the lowly spreadsheet stands alone.

Overview of Select Building Physics Software
Software Developer Capability


US Department of Energy

Daylighting analysis using ray-tracing simulation

Simulink (Matlab)


Component-based, algorithmic platform


David Rutten/Robert McNeel & Associates

Component-based, algorithmic platform for optimization studies

Rhinoceros (Rhino)

Robert McNeel & Associates

Three-dimensional visualization tool



Environmental analysis, including daylighting and shading

Green Building Studio


Web-based, concept-level energy analysis software

Integrated Environmental Solutions Virtual Environment (IESVE)

Integrated Environmental Solutions

Thermal/energy simulation, natural ventilation analysis


Lawrence Berkeley National Laboratory (LBNL) for the US Department of Energy (DOE)

Whole-building thermal/energy modeling


James J. Hirsch & Associates (JJH) and LBNL for the DOE

Thermal/energy modeling

Transient Energy System Simulation tool (TRNSYS)

University of Wisconsin-Madison

Component-based thermal/energy modeling


Harvard Graduate School of Design

Environmental analysis plug-in for Rhino


Christoph Reinhart

Modeling of daylight availability and energy savings from control systems



Simple building energy modeling, California focus


Andy Payne/Jason Kelly Johnson

Plug-in for Grasshopper for real-time sensor networks

Generative Components

Bentley Systems

Algorithmic optimization software



Three-dimensional visualization/CAD tool


Mentor Graphics

Computational fluid dynamic (CFD) modeling


Integrated Environmental Solutions

Bulk air flow analysis


Bentley Systems

CAD tool



Glazing and window technical and performance construction tool

Russell Fortmeyer is an engineer, sustainability consultant, and journalist based in Los Angeles.


[ Page 4 of 4 ]  previous page Page 1 Page 2 Page 3 Page 4
Originally published in GreenSource
Originally published in May 2011