The Army is still going for Gold and Platinum despite recent legislation calling a halt to LEED spending.

The federal government has been one of the biggest supporters of LEED certification in the last few years, with the General Services Administration (GSA) requiring basic LEED certification for all federal buildings starting in 2003 and then upping that requirement to LEED Gold in 2010.

The military has been on the cutting edge of green building from the beginning. The Navy adopted sustainable design principles before LEED even existed, as we reported way back in 1998. The Army embraced LEED in 2006 and recently began the much more radical work of moving all its installations to net-zero energy, water, and waste. As Katherine Hammack, assistant secretary of the Army for installations, energy, and the environment, put it to EBN earlier this year, "Energy security is mission critical."

It doesn't cost more

We feared that might all change when we saw that the most recent military appropriations legislation requires explicit justification for any spending on LEED above the Silver level. What's worse, this decision pretends to be about money but appears to have been made over certified wood credits. (Watch this space for in-depth coverage of the "wood wars" in coming weeks.)

Hammack is having none of it. In a call with reporters yesterday, she reiterated the Army's commitment to net-zero and LEED and gave an update about some of the progress that's already been made. "We're finding it does not cost more to design and construct to LEED" standards, Hammack said.

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Lighter, more fire-resistant, and a better insulator, autoclaved aerated concrete caught on in the rest of the world ages ago. It's taking a lot longer in the U.S.

To read what manufacturers and distributors say about it, you'd think autoclaved aerated concrete (AAC) was some kind of new, space-age environmental miracle.

Although it certainly has some nifty properties, AAC isn't new and isn't miraculous--but it's certainly popular in Europe, and has been for decades; according to one source, it accounted for 60% of all new construction in Germany in 2006. It has enjoyed pretty flat market share (of near zero) here in the U.S., though, since it was first introduced in the 1990s.

Is there space for AAC in the U.S. market? Should the green building community be working to make space?

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July, 2011 dust storm in Phoenix, Arizona. Photo: Militec, Inc. Click on image to enlarge.

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Will environmental product declarations end greenwashing for good? Not so fast.

This is Part 3 in our series on transparency.

Part 1: Why We Care About Product Transparency

Part 2: Why We Need "Nutrition Labels" for Building Products

We all want to know more about where our building products come from and what's in them. Finally, with the emergence of environmental product declarations, we're going to find out!

Aren't we?

The promise of the product transparency movement is huge, and we think this nascent trend is going to play a big role in sustainable manufacturing, design, construction, and operations in the next few years--one reason why we dedicated this month's EBN feature to product transparency.

But things aren't as simple as they might seem in this uncharted realm. There's more to environmental product declarations (EPDs) than meets the eye. And in many cases, there's less than meets the eye too. While many manufacturers are working hard to show leadership on true transparency, there is also a risk of insidious greenwashing like we've never seen before.

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Contact with nature is not just an amenity: it's important for well-being. Green walls liven up urban spaces while improving building performance.

I live in Vermont, where agriculture is an integral part of our culture. I drive past the farms as the seasons change and see when the corn is high or when too much rain has made plowing impossible. And the family sees the results at the local farmer's market. Whenever I visit urban areas, I inevitably end up at the local park or waterfront for my early-morning runs.
I value this connection with the natural world--or biophilia--and maybe it's more than just a lifestyle choice. Biophilia has been shown to have tangible benefits, including reduced stress, improved productivity, and faster healing, to name a few, but integrating greenery among limited--and expensive--urban real estate is no easy task. Maybe the answer is to think vertically.

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Our pellet stove has DC fans and a kit that allows us to hook it up to a battery to power those fans in the event of a power outage. Photo: Alex Wilson. Click on image to enlarge.

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There are more than 20 different standardized tests manufacturers can invoke to "qualify" as a code-accepted weather-resistive barrier (WRB); with our GreenSpec section on WRBs, we've picked just one that we think does the job.

It's not easy being a weather-resistive barrier (WRB): it has to stop liquid water, be tough and not tear, but also be flexible to wrap around building elements. And it often needs to be vapor-permeable to promote drying.

Finally, water-tight standards

In the past, manufacturers could cherry-pick the standardized test to use to "qualify." That's how we ended up with industry acceptance of perforated and cross-woven housewrap that literally leaks like a sieve.

Now we have a new ASTM "Standard Specification for Vapor Permeable Flexible Sheet Water-Resistive Barriers Intended for Mechanical Attachment." This standard also aligns with the latest version of the ICC-ES Acceptable Criteria (AC) 38–"Acceptance Criteria for Water-Resistive Barriers (PDF)." The table below presents the requirements for WRBs used in the new standard and now by GreenSpec.

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This exterior window shade in Florida blocks most of the solar gain, yet allows some view out. Photo: Alex Wilson. Click on image to enlarge.

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BIPV has yet to reach its full potential in the U.S., but a couple companies are giving it a shot.

Building-integrated photovoltaics (BIPV)--photovoltaic (PV) modules integrated into functional building elements, such as roofs, glazings, and building façades--are fairly common in Europe and Asia. Yet finding commercial BIPV façade products
in the U.S. is nearly impossible. Why is that?

There are a number of possibilities, including lack of suitable new projects due to the economy, a tempestuous PV market, and concerns about reliability and performance, to name a few--but the real reason might be a lot simpler.

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Passive solar design is a key element of creating resilient homes.

A passive solar home in Halifax, Vermont. High-SHGC, triple-glazed, south-facing windows were used to improve the direct-gain passive solar performance. Click on image to enlarge.

As I discussed in last week's blog, a resilient home is extremely well-insulated, so that it can be kept warm with very little supplemental heat--and if power or heating fuel is lost, for some reason, there won't be risk of homeowners getting dangerously cold or their pipes freezing. If we design and orient the house in such a way that natural heating from the sun can occur, we add to that resilience and further reduce the risk of the house getting too cold in the winter.

Passive solar heating

I had the good fortune of working in Santa Fe, New Mexico for a solar energy organization in the late-1970s, when the passive solar energy movement was just emerging. Northern New Mexico was the epicenter of research into passive solar--the effort, ironically, being led by Los Alamos National Laboratory, which, a generation earlier, had brought us the nuclear age.

It was an exciting time. The relationship between solar gain and thermal storage was becoming understood. It was discovered that very simple south-facing windows and high-mass walls and floors were not only far simpler than the very complex active solar heating systems that emerged (briefly) in the early 70s, but they also worked better.

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