Wednesday, November 25, 2009  

Measuring Environmental Performance of Green Buildings

Selecting building products based on minimum life cycle economic impacts is relatively straightforward. Products have been bought and sold in the marketplace, which has established their first cost, and sound analytical procedures to quantify life cycle cost have been developed and employed for over 20 years. In addition to initial cost, future costs that contribute to life cycle cost include the cost of energy, operation and maintenance, labor and supplies, replacement parts, and eventually the cost of decommissioning or recycling the system.

Environmental performance can be quantified using the evolving, multi-disciplinary approach known as environmental life cycle assessment (LCA). Environmental life cycle assessment (LCA) is a “cradle-to-grave” systems approach for measuring environmental performance. It is based on the belief that all stages in the life of a product generate environmental impacts and must therefore be analyzed. The stages include:

Raw materials acquisition
Product manufacture
Operation and maintenance
Recycling and waste management

An analysis that excludes any of these stages is limited because it ignores the full range of upstream and downstream impacts of stage-specific processes.

The strength of environmental life cycle assessment is its comprehensive, multi-dimensional scope. Many sustainable building claims and strategies are now based on a single life cycle stage or a single environmental impact. A product is claimed to be “green” simply because it has recycled content, or accused of not being green because it emits volatile organic compounds (VOCs) during its installation and use. These single-attribute claims may be misleading because they ignore the possibility that other life cycle stages, or other environmental impacts, may yield offsetting effects.

For example, the recycled content product may have a high embodied energy content, leading to resource depletion, global warming, and acid rain impacts during the raw materials acquisition, manufacturing, and transportation life cycle stages. LCA thus broadens the environmental discussion by accounting for shifts of environmental problems from one life cycle stage to another, or one environmental medium (land, air, or water) to another. The benefit of the LCA approach is in implementing a trade-off analysis to achieve a genuine reduction in overall environmental impact, rather than a simple shift of impact.

Excerpted from Green Building: Project Planning & Cost Estimating, 2nd Ed. The new 2nd edition has been completely updated with the latest in green building technologies, design concepts, standards, and costs. Includes Means’ Green Building CostWorks CD at no additional cost. A Unique Cost Reference for Architects, Engineers, Contractors, & Building Owners/Managers.

RS Means, November 25, 2009.

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Thursday, November 12, 2009  

Beyond LEED: Living Building Challenge 2.0 Certification Unveiled This week the ILBI released it's New Green Building Standards

This week the International Living Building Institute released its new green building standard to the public at Greenbuild 2009. Version 2.0 expands on its already impressive focus to now cover social issues – any Certified Living Building must be net-zero energy, net-zero water, non-toxic, provide for habitat restoration on sister sites, and urban agriculture is mandated. The 20 imperatives, all of which must be addressed, go well beyond the simple efficiency standards that our industry seems content to comply with before calling a project ’sustainable’. Seriously, read this thing!

Jason F. McLennan and his team have done a wonderful thing in giving us the language and rules to move beyond LEED. Industry spokespeople will call this ‘idoitic’, ‘unreasonable’ and ‘impossible’. Don’t be scared industry spokespeople – change happens, we move forward, let’s do it together. Remember when you said the same things about LEED, which is now mandated in cities and counties all over the world?

The International Living Building Institute was founded in 2009 by the Cascadia Region Green Building Council to promote to the creation of Living Buildings, sites and communities in countries around the world. There are currently 70 projects pursuing certification in the US under the previous release.

One of the most important features of LBC is that it measures the actual performance of buildings. Basically this means that a year after a building was built, measurements are taken to ensure that it is, in fact, net zero in terms of energy and water, etc. This is a big distinction from existing requirements like LEED and CA’s Title 24 which measure performance models and do not hold projects accountable to live up to those models.

This is also the first standard to address social justice and equity issues. In their own words: “The intent of the Equity Petal is to correlate the impacts of design and development to its ability to foster a true sense of community. A society that embraces all sectors of humanity and allows the dignity of equal access is a civilization in the best position to make decisions that protect and restore the natural environment.”

“The simple concept of green buildings has generally produced more efficient buildings and smaller footprints. But that is no longer enough,” says McLennan. “With version 2.0 addressing issues of food, transportation and social justice, we expect a considerable leap forward will happen once again.”

We are interested to hear what you think about this new standard – sound off in the comments!

by Trey Farmer, 11/12/09

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Friday, October 30, 2009  

Renovating a Home to Become Net-Zero

BOULDER - With the recent construction of an near net-zero house in Boulder, potential homeowners nationwide might be encouraged to go just a little greener when they build.

Located at 2300 Kohler Drive, the home of David Humphrey and Jamie Gardner was featured in a recent episode of the Discovery Channel’s popular “Renovation Nation,” a program showcasing green-building projects across the country.

The home has 3,547 square feet of living space with a 1,400-square-foot unfinished basement. The entire development project was the result of a collaborative partnership with Boulder-based Ellis Construction Inc., Namasté Solar Electric Inc. and Colorado Geothermal Drilling.

Jonathan Ernst, a solar engineer at Namasté, the photovoltaic panels used for the house are the highest efficiency panels currently available on the market – and are also readily available to anyone who wants to go solar.

While the building partners declined to disclose specific costs on the house, Namasté co-owner Heather Leanne Nangle estimated the current retail cost – before energy rebates or tax credits – to install a 7-kilowatt grid-tied, flush roof-mount photovoltaic system in a similar residential development could typically cost around $47,000.

Nangle said, the Xcel Energy Solar Rewards rebate for this system would be $24,000, while the federal tax credit would be $7,200. Including rebates, this brings the cost of the photovoltaic system down to $15,800.

Nangle said this price range depends on many factors, such as the number photovoltaic panels installed and the kilowatt power of the house. While the average residential system size is 5 kilowatts, the house on Kohler Drive runs at 8.28 kilowatts.

Ernst said there was nothing done to the Kohler Drive house that couldn’t be done to just about any new construction or retrofit project.

“The only thing out of the ordinary is that we were being filmed,” he laughed.

Another key player in the net-zero house is its 5-ton geothermal heating pump system, installed by Dan Rau, owner of Colorado Geothermal Drilling. The system circulates water from 300 feet underground, which is then stabilized to consistent temperatures in order to heat or cool the house.

Rau said while the geothermal system installed was a standard one used for many houses in Colorado, the house on Kohler Drive will have one special element added within the next few months.

“We’re going to put in an energy-monitoring system that will kick up minute-by-minute and show how much the whole system costs to operate, as well as how efficiently it’s running,” Rau said. “We install a geothermal pump system about once a week, but we only install two or three of these energy-monitoring systems a year,” he added.

Rau said implementing a standard geothermal pump system will typically cost $3 to $5 per square foot more than the cost of putting in a conventional gas/electric heating and air unit.

General contractor David Ellis said these renewable energy technologies will enable the house to produce all the energy it uses. "In a net-zero house, you’re going to try to use as little fossil fuel as possible to produce energy,” he said. “In order to do this, we had to apply different levels of building practices to the house.”‘

These green-building practices were put into action before construction even began. First, Ellis and his crew began with a systematic deconstruction of the existing house on the site, sending everything out to be recycled, including construction waste.

During the building process, the contractors applied a tight seal to the house with spray foam insulation, creating an air barrier to prevent heating or cooling from leaking out. The exterior siding was constructed of cement board with recycled content, and a rigid foam insulation was used on the outside of the foundation walls. The entire frame of the house was constructed from forest stewardship council lumber, coming only from sustainable managed forests.

Ductwork in the house was sealed, and a heat recovery ventilator – a device that naturally produces a continuous intake and exhaust of air flow through the house – was installed in the attic.

In finishing the interior of the house, Ellis used low VOC paints and water-based floor finishes, and installed energy efficient windows and lighting.

Ellis, along with his colleagues from Namasté and Colorado Geothermal, agrees that everything done in the house can easily be implemented in any new construction or retrofit project.

“All of this stuff that we did makes sense,” he said. “The house was built really green through a lot of common sense things – nothing exotic, just stuff like good insulation. These are things I’d want to do, whether the house was dubbed ‘green’ or not. These are just good building practices.”

Ellis gives credit to homeowners Humphrey and Gardner for adding to the scope of the work.

“It’s not that difficult to reach the minimum requirements for Boulder’s green building code, but David and Jamie went above and beyond and invested way more than that into this house,” he said.

Ellis said that meeting the new Boulder County green code will typically add on about ten percent above the cost of a new construction project for houses of up to 5,000 square feet. However, Ellis added, costs for the Kohler Drive house probably topped at more than 20 percent above those estimates, thanks to the commitment made by the owners to go as near net zero as possible.

As to whether or not the couple achieved that goal, the proof came when the home was given its Home Energy Rater score. The lower the number, the more energy efficient the building. Boulder’s green codes require a score of 60 or less – and the Kohler Drive house came through with flying colors at a score of 14.

For Ellis, who spent this past year in an intensive study of renewable energy building practices, the timing of the Kohler Drive project couldn’t have been more serendipitous. Now, thanks to the completion of this net-zero home, Ellis is fast becoming known as one of the country’s premier green builders.

“A year ago I had never built anything green, and now I’m one of the few builders who have actually built a net-zero house,” he said. “This is where homebuilding is going, and I’ve embraced it. And the best thing of all is that I can walk away knowing that I’ve built a better, healthier house to live in.”

By Keely Brown, Boulder county Business Report, October 30, 2009.

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