Building Energy Performance—Going Mainstream

The big trend in architecture today is designing sustainable buildings. There are a number of practices where sustainable design is part of the very soul of the firm. Michael Hopkins' firm in the U.K. is an excellent example of this. They win large projects in the U.S. from their London office because their customers really care about building operating costs. For many other firms, however, designers are simply not equipped with a true understanding of sustainability, how to really design energy efficient buildings, and what their correct role should be in the supply chain between themselves, the engineers, and the building product manufacturers. My prediction is that for an architectural practice, being "energy-aware" is going to make the difference between being awarded projects or losing them at an ever increasing rate.

The Growing Importance of Green

Why is sustainable design so important? Six billion people, sky-rocketing energy prices, a shortage of natural gas with no end in sight, building owner expectations, and perhaps most importantly, government regulations are all driving architects around the world to view this problem as "their problem." If I don't have your attention yet, consider this:

• Every day, more solar energy falls to the earth than the total amount of energy the planet's 6 billion inhabitants would consume in 26 years.
• A 30% saving in energy costs can translate into a 6% increase in net operating income of a typical office building's operating expenses.
• For home air conditioners, each degree setting below 23 C/78 F will increase energy consumption by approximately 8%.
• Every year, US businesses pour at least $25 billion of profits down the drain in the form of wasted energy from inefficient buildings.
• One sixth of the electricity consumed in the U.S. goes to cool buildings, at an annual cost of $40 billion.
• Advanced glazing with spectrally selective coatings can reduce the space cooling requirements of new buildings in hot climates by more than 40%.

The numbers above have grabbed the attention of building owners. If they haven't gotten yours, governments will! Designers will soon have to prove that their designs meet national energy performance standards. 2006 is going to be a very important year in Europe. Today, standards regarding energy performance differ between member nations of the EU. In some countries, there are no requirements and in other countries like Austria, architects must provide a certificate of energy efficiency. Starting in 2006, there will be one standard, the EPD (Energy Performance Directive). Architects have to get ready to comply with this.

LEED (Leadership in Energy and Environmental Design) is the hot topic in the U.S. The U.S. requires all new federal buildings to achieve a LEED "silver" certification. Several corporations are also requiring similar certifications or levels of performance. These requirements are creating a demand for firms who can design green buildings and are trained to attain the building LEED certification. This is why some large architectural practices are putting hundreds of their employees through training. California and New York have the highest electricity costs in the U.S. and consequently they are the most aggressive in implementing measures to meet these design expectations. California will mandate the use of advanced technologies to reduce energy demands by the end of next year.

And finally in China, where economic growth has taken center stage over the past two decades, "Green" is now the topic of discussion. The major design institutes are trying to figure out how to design energy-efficient buildings.

The Tools are Already Here

Today's Virtual Building technology already allows architects to visualize, analyze, and optimize their designs even during the earliest design stages, without having to make each new project an expensive experiment. There are a great number of tools available on the market that work in conjunction with building modeling tools to support this green evolution. These include:

• ArchiPHYSIK: ArchiPHYSIK has been used to analyze energy efficiency within building design for 11 years, and has been directly integrating with architectural 3D models for 5 years (see Figure 1). "Europe is still an early adopter market in terms of using computers to perform energy simulations, but the 2006 European Directive will force all designers to calculate the energy performance of buildings. Then it will become mainstream across Europe." That is the view of Johann Riegler, Managing Director of A-NULL EDV GmbH, Austria, who are the creators and developers of ArchiPHYSIK.
• Green Building Studio: John Kennedy, President & CTO of GeoPraxis, Inc. is a key figure in the US drive toward building energy efficiency. He rightly points out that "if an architect is not learning and practicing sustainable design, they will soon not be qualified to work on a lot of projects." The Green Building Studio is a free web service that provides immediate energy analysis results within ArchiCAD.
• ECOTECT: According to Andrew Marsh, Managing Director of ECOTECT in the U.K., who is also an architect by training: "Designing energy-efficient buildings is an ethical responsibility. If the client's desire to save a small amount of money on construction costs is going to result in a significant energy cost (in this case a 'societal' cost) over the full 80-100 year life of the building, it is the architect's responsibility to ensure this does not happen."

Energy Simulation at Work

There were two recent examples of building design which showed me that architects still have a long way to go to make energy simulation an integral part of their work. One was is a small project—my new home. The other is New York's Freedom Tower.

In the case of determining the energy efficiency of the Freedom Tower, the Lawrence Berkeley National Laboratory (LBNL) and the National Renewable Energy Laboratory (NREL) provided their know-how on the project. The Freedom Tower design features two elaborate "pleated skin" façades. LBNL modeled the middle (office space) section of the tall and twisting building with ArchiCAD to import the complex building skin geometry into its energy analysis application, EnergyPlus. NREL added the definition of mechanical equipment and systems. LBNL and NREL are simulating the performance of different building skin alternatives, as an integral part of the rest of the building, with EnergyPlus to determine optimal daylighting design and overall building energy performance. The architects and the mechanical engineers on the project are incorporating the results of the simulation into their design decision-making.

Vladimir Bazjanac of LBNL, who led the effort in the Freedom Tower project, has definite views on the subject of sustainable buildings. "The building industry is the only major industry that regularly delivers its product to the market without first thoroughly testing it. The future of architectural practice may depend on architects' ability to test the performance of their designs before final design decisions are made and before the construction starts or the building is occupied and used. That will mean creating "virtual buildings" (detailed computer representations of buildings) for which all types of performance, including energy performance, can be tested in simulation to find optimal solutions and understand how they will perform under different conditions."

The images shown in Figure 2 are a result of an analysis of my new home using ECOTECT. The house is located on a glider plane field, so there is a vast amount of glass with a north-east exposure. While this is great for the view, it can also be a significant source of heat loss at night and heat gain when the low level sun shines through in the mornings.

The graph on the top shows a breakdown of all the different sources of heat loss and gain acting on the house throughout the year. The red area below the center line clearly indicates that the heat loss through the external fabric, in this case the glass, is significant over winter and for most of spring and autumn. Offsetting this are some solar gains but certainly not enough—so lots of heating will be required. Ouch!!

A tool like ECOTECT allows the designer to consider many different aspects of building performance. In addition to the thermal analysis, the lower image in Figure 2 shows air speeds through the house under certain ventilation conditions. The image in Figure 3 shows the distribution of natural light over the floor in the main living area.

Although some adjustments were made to the design of my house as a result of the analysis with ECOTECT, more could have been made if we were earlier on in the process. Definitely, my architect was not energy-aware and he left everything up to the engineer on the project "after the design was complete".

Some Recommendations for Going Green

Two projects—one very large and one very small. Both can benefit greatly in the early and detailed design phase from energy simulation. Unfortunately, this kind of building simulation is the exception so far rather than the rule in design.

So here are my recommended do's and don'ts for an architect practicing today to stay competitive in the upcoming green revolution:

• Don't — feel like you have to immediately master the new simulation programs that perform the analysis. Grow into these programs over time. Look for young architects coming out of school that have the aptitude and interest in using these programs. For those who will never grow to use them, it is absolutely fine. Again, just be the best in the world at providing the data necessary to run the simulations and interpret the results.
• Don't — wait until the design is done to have a simulation performed. It is best to do these kinds of studies at the conceptual design stage so that you still have time to make modifications to the design for optimizing the energy efficiency of the building.
• Do — begin to read about sustainable design and which tips and tricks you can employ to keep buildings warmer in the winter and cooler in the summer without additional energy consumption. A good place to start learning is the World Green Building Council website.
• Do — develop an understanding for energy-efficient building components and attempt to specify them as much as possible in your designs.
• Do — develop a relationship with an engineer that employs advanced energy simulation software. Be very good at generating the necessary inputs so that it is easy to run analysis against your designs.
• Do — market your newly found skills. Architects don't normally appeal to clients with an energy competence message. It's time!
• Do — consider starting your projects in 3D from the outset. The virtual model linked to software assessing building energy efficiency can lead to improvement in the overall design.

This is a big trend going on in the profession, a trend with no end in sight and only possibilities. The world's energy needs will grow over 50% by 2025 to a staggering 623 quadrillion BTUs. I believe there will be good times ahead for your practice if you are able to insert your services squarely into the process of taking on the energy challenge.

Acknowledgements

Special thanks to Johann Riegler, Managing Director of A-NULL EDV GmbH; Andrew Marsh Ph.D., Managing Director of ECOTECT; John Kennedy, President & CTO of GeoPraxis, Inc.; and Vladimir Bazjanac Ph.D. of Lawrence Berkeley National Laboratory for their contributions to this article.

About the Author

Dominic Gallello is the President & CEO of Graphisoft. He has a long track record of helping to shape some of the major trends in the design software industry. Prior to Graphisoft, Mr. Gallello spent approximately 20 years in various executive positions at Autodesk and Intergraph. Having lived in Asia and Europe, Mr. Gallello brings a unique perspective to customer requirements and possibilities.

Note: The views expressed in Viewpoint articles are those of the individual authors and do not necessarily reflect those of AECbytes. Also, no advertising or sponsorship is accepted for Viewpoint articles.

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