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Constructing a Foundation for 'Net-Zero' Buildings
Joel Makower, 2 Apr 06

Can buildings use zero net energy, be carbon neutral, and still be commercially viable? That intriguing question is being asked these days -- not by fringe green building champions, but by major multinationals. Clearly, they see net-zero buildings yielding net-positive profits.

The most recent development came last week from the World Business Council for Sustainable Development, which said it is forming an alliance of companies "to determine how buildings can be designed and constructed so that they use no energy from external power grids, are carbon neutral, and can be built and operated at fair market values."

The industry effort is led by United Technologies Corp. -- which makes elevators, cooling/heating, and on-site power systems, among other products -- and Lafarge Group, which manufacturers such building materials as cement, concrete, aggregates, gypsum, and roofing. Along with other companies, the alliance plans to produce reports that together "will form a roadmap to transform the building industry." The first report will document existing green building successes and setbacks, the second will identify the full range of present and future opportunities, and the third will present a unified industry strategy for realizing those opportunities by 2050, specifically in China, India, Brazil, the U.S., and the E.U.

This is no small matter. According to the Pew Center on Global Climate Change:

The energy services required by residential, commercial, and industrial buildings produce approximately 43% of U.S. CO2 emissions. Additional [greenhouse gas] emissions result from the manufacture of building materials and products, the transport of construction and demolition materials, and the increased passenger and freight transportation associated with urban sprawl. As a result, an effective U.S. climate change strategy must consider options for reducing the GHG emissions associated with how buildings are constructed, used, and located.

The idea of net-zero buildings is not new. For example, Habitat for Humanity has built a net-zero home in Colorado as a model for what comfortable and affordable green housing could look like. Last year, a British builder opened a set of flats in central London that can be entirely self-sufficient in their energy needs.

Commercial buildings also have gone the net-zero route. A few years ago, Shaklee Corp., a distributor of consumer health-care products, was certified as the first Climate Neutral enterprise in the U.S. after it reduced energy use by more than 30% internally and offset all remaining greenhouse gas emissions to zero. Pepsi has built a plant in Oregon with sufficient renewable energy to power it entirely. The Northeast Sustainable Energy Association recently announced a Zero-Energy Building Award to recognize net-zero-energy buildings designed for the unique northeast climate.

Still, such projects remain relatively few and far between.

What will it take to make net-zero buildings the norm? According to a report last year from Pew, it will take a variety of emerging technologies and techniques, including:

  • sealing methods that address unseen air leaks,
  • electrochromic windows offering the dynamic control of infrared energy,
  • unconventional water heaters (solar, heat pump, gas condensing, and tankless),
  • inexpensive highly efficient nanocomposite materials for solar energy conversion,
  • thermoelectric materials that can transform heat directly into electrical energy,
  • solid state lighting that uses the emission of semi-conductor diodes to directly produce light at a fraction of the energy of current fluorescent lighting,
  • selective water sorbent technologies that offer the performance of ground-coupled heat pumps at the cost of traditional systems,
  • abundant sensors dispersed through buildings with continuously optimizing control devices, and
  • 80-90 percent efficient integrated energy systems that provide on-site power as well as heating, cooling, and dehumidification.

It's far from clear whether the companies forming the fledgling WBCSD alliance will have the bandwidth to address all those needs. But others are. Two examples from the above list: Researchers at Brookhaven National Lab last year announced that "Thin films made of so-called thermoelectric materials could be used to convert heat . . . into electrical energy without producing carbon dioxide or other emissions." And researchers at Lawrence Berkeley National Lab say they are working to overcome barriers to the economical manufacture of new solid-state light-emitting diodes (LEDs) to produce "cool, economical home and commercial lighting."

It is encouraging to see a corps of very large companies -- Connecticut-based UTC earned $42 billion in 2005; Paris-based Lafarge earned €16 billion ($19.4 billion) -- talking the net-zero talk. Clearly, we've come a long way from the days when "green buildings" were considered outside the mainstream. And they're not alone. BASF, Dow, and Dupont are just a few of the other behemoth companies that have staked out green building as a major market opportunity.

But it's important to keep in mind that green buildings -- like all buildings -- are more than the sum of their parts, however green they may be. It will take a concerted effort by architects, planners, developers, zoning boards, utility officials, and their respective customers to ensure that "net-zero" becomes more than just an exemplary vision punctuated by occasional success stories.

If the new WBCSD initiative can bring together, educate, and activate these disparate players, they'll have built a strong foundation for transforming the built environment -- and the natural environment in which it lives.

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The WBCSD is not impressive as an innovative organization. the Rocky Mountain Institute headquarter building is famous worldwide as the first example of modern comfortable passive solar building. Designed by Amory Lovins and others, it was self-built between 1982 and 1984. It is located at 2200 m above sea level in Old Snowmass, close to Aspen; the building maintains perfect comfort with external temperatures frequently below minus 30 Celsius. There are 2 wood fired stoves as a backup for extreme cold days or cloudy weather. The payback time for the extra investments to build it that way was 10 months with 1984 technologies. The building is also a banana Farm.

Posted by: eric ezechieli on 2 Apr 06

In Europe today there are over 6000 built and operative passive solar buildings, most of them are also net energy producers, mostly in germany and northern Europe. The biulding costs are absolutely competitive on the market
see also

Posted by: eric ezechieli on 2 Apr 06

Great post Joel. While we push toward Net Zero Energy, we can get to Net Zero Carbon even quicker. As always, efficiency improvements will come first, bringing loads low enough to be met with renewable sources. Our architecture firm is getting very close to designing buildings whose energy consumption would not make CO2 levels rise, while keeping their cost competitive in the market. Within 5 to 10 years, net zero should be quite easy to do.

Posted by: David Foley on 2 Apr 06

I don't know what the definition of net-zero building is but...
We built a passive solar heated house 10 years ago and now with our PV system we produce all the energy we need on a yearly basis. And it cost about the same as a typical house to build.

Am I missing something here?

Posted by: Rich on 3 Apr 06

Some folks who have left comments seem confused about the significance of this article. It is one thing to achieve 'zero energy balance' in small buildings with one or two floors, but doing the same with 'skyscrapers' is something else entirely... such monstrosities only exist because oil used to be cheap.

Developing low CO2 emission (during manufacture) materials suitable for high rise construction isn't the only challenge.

~~Pumping water to the top, dealing with heating, ventilation and air-conditioning loads that depend more on internal factors than the external skin... (Pssst... not that it would do much good if they did, but most of these buildings have windows which don't open -- well, I suppose we could break them... but winter will surely come again.)

~~Power the elevators... (Want to climb 80 flights of stairs every Monday morning? Oh and Tuesday, Wednesday, Thursday, and Friday too. Uh, hmmm...)

~~Powering computers, coffee pots, microwaves and lights...

Meanwhile, these buildings often have little or no solar gain due to shading in dense urban settings... even wind power for such huge structures would require blade diameters larger than the footprints of the buildings.

This is a significant challenge. It seems inevitable that the cities will continue to put reliance on outlying areas for support instead.

One of the most promising, yet poorly reported possibilities is OTEC - Ocean Thermal Energy Conversion... it was tested, proven, and then dismantled... but there probably isn't enough time (or cheap oil) to build out the capacity required to fill the looming Peak Oil gap.

The line for the water cooler starts here... Or... Perhaps we will simply abandon all these ugly relics of the Oil Age. The death of the cubicle is nearly upon us -- well at least there's a little cloudy silver in the lining. Aye?

Posted by: logspirit on 3 Apr 06



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