Green Building News

Green Building News August 3, 2010

Solar Trees® Create Clean Energy, Shaded Parking and Electric Vehicle Charging for Dell Headquarters

Solar Trees now producing more than 130kW of clean solar power annually

Envision Solar International's extensive portfolio of solar parking arrays includes a design project for a solar shaded parking structure at Dell's headquarters in Round Rock, Texas. This configuration of Solar Trees®, called a Solar Grove®, located in the Dell employee parking lot generates clean electricity directly from the sun, more than 130kW of solar power annually. The structure simultaneously shades 50 parking spaces. In an example of Vehicle-to-Grid (V2G) technology, the solar arrays also incorporate two Envision Solar CleanCharge(TM) solar charging stations for Electric Vehicles (EVs) and Plug-In Hybrid Electric Vehicles (PHEVs).


Home Size Continues to Decline; Buyers Increasingly Opt for Single-Story Homes

The size of new single-family homes completed declined last year, dropping to a nationwide average of 2,438 square feet, according to detailed information about the characteristics of new homes completed in 2009 that was released recently by the Census Bureau.

After increasing continually for nearly three decades, the average size of single-family homes completed in the United States peaked at 2,521 square feet in 2007. It was essentially flat in 2008, then dropped in 2009, so that new single-family homes were almost 100 square feet smaller in 2009 than in 2007.

"We also saw a decline in the size of new homes when the economy lapsed into recession in the early 1980s," said NAHB Chief Economist David Crowe. "The decline of the early 1980s turned out to be temporary, but this time the decline is related to phenomena such as an increased share of first-time home buyers, a desire to keep energy costs down, smaller amounts of equity in existing homes to roll into the next home, tighter credit standards and less focus on the investment component of buying a home. Many of these tendencies are likely to persist and continue affecting the new home market for an extended period."

In keeping with their slightly smaller size, new single-family homes completed in 2009 had fewer bedrooms than previously. After increasing for almost 20 years, the proportion of single-family homes with four bedrooms or more topped out at 39 percent in 2005; it was 34 percent last year. The proportion of single-family homes with three bedrooms increased from 49 percent to 53 percent between 2005 and 2009.

New single-family homes completed last year also had fewer bathrooms than previously. The proportion of homes with three or more bathrooms was 24 percent last year, a decline from the peak of 28 percent in both 2007 and 2008. The percentage of single-family homes with two bathrooms increased from 35 to 37 last year, and the percentage with 2 1/2 bathrooms was at 31 percent for the third consecutive year. The proportion of single-family homes with 1 or 1 1/2 bathrooms has been below 10 percent for more than a decade.

In 1973, the first year for which the Census Bureau reports characteristics of single-family homes completed, most new single-family homes  - 67 percent - had only one story. Twenty-three percent had two or more stories, and 10 percent were split levels.

The proportion of one-story homes declined steadily for more than three decades, dropping to a low of 43 percent in 2006 and 2007. At the same time, the proportion of single-family homes with two or more stories increased, rising from 23 percent in 1973 to a high of 57 percent in 2006 (split level homes currently account for less than one percent of all single-family homes ). Since 2006 the trends have been reversed, as the share of single-family homes with one-story increased to 47 percent last year, while the share with two or more stories dropped to 53 percent.

The Census Bureau s data on characteristics of completed single-family homes also showed regional differences.

In 1973, less than half of all new single-family homes completed had air conditioning; in 2009, 88 percent were air conditioned nationwide. Regionally, the proportion ranged from a low of 69 percent in the West to a high of 99 percent in the South. The Northeast and Midwest were at 75 percent and 90 percent, respectively.

Nationwide, 62 percent of new single-family homes completed in 2009 had two-car garages, and 17 percent had garages for three or more cars. However, there were clear regional differences. Three-car garages were found in only about 11 percent of homes in the Northeast and the South. In the Midwest, 30 percent of all homes had three-car garages, and in the West, 26 percent.

Regional differences were especially pronounced in the selection of exterior wall material. Nationwide, 34 percent of all single-family homes completed in 2009 homes had vinyl siding, 23 percent were brick, 19 percent were stucco, and 13 percent had fiber cement siding.

Vinyl siding predominates in the Northeast, where it accounted for 74 percent of the market; wood was a distant second with a 12 percent market share. In the Midwest, vinyl siding accounted for 62 percent of the market while wood and brick were at 15 percent and 11 percent, respectively.

Brick was the leader in the South, where it was found in 40 percent of new single-family homes. Twenty-eight percent of new homes in the South had vinyl siding and 13 percent had stucco.

The Census Bureau began reporting statistics on fiber cement siding, which is relatively new to the market, in 2005. It already accounts for 24 percent of the market in the West. Stucco and wood account for 52 percent and 15 percent of the market, respectively, in that region.


DOE Announces $30 Million for Energy-Efficient Housing Partnerships

The U.S. Department of Energy recently announced 15 research and deployment partnerships to help dramatically improve the energy efficiency of American homes. These highly-qualified, multidisciplinary teams will receive a total of up to $30 million for the initial eighteen months of the projects to deliver innovative energy efficiency strategies to the residential market and address barriers to bringing high-efficiency homes within reach for all Americans. A total of up to $20 million per year will also be made available for the partnerships for three potential one-year extensions. These research and deployment partnerships will provide technical assistance to retrofit projects and will leverage industry expertise and funding to support DOE's energy efficiency retrofit programs. 

The partnerships will provide additional support to ongoing retrofit initiatives that are making cost-effective energy efficiency retrofits easily accessible to hundreds of thousands of American homes and businesses.  These partnerships will research and deploy new technologies and demonstration projects, and provide systems engineering, quality assurance, and outreach for retrofit projects throughout the country.

Existing techniques and technologies in energy efficiency retrofitting - such as air-tight ducts, windows and doors, heating and cooling systems, insulation and caulking - can reduce energy use by up to 40 percent per home and cut energy bills by $40 billion annually.

View a description of the selected teams, which will each receive between $500,000 and $2.5 million depending on their performance.


21st Century Building Expo & Conference - Sept. 15-17

Held in Charlotte, North Carolina, this conference offers a line-up of courses and seminars for everyone in the home building industry. More than 50 general session seminars, North Carolina Builder Institute courses and NAHB Education classes are on the schedule. Courses include The Ins & Outs of Energy Efficiency Programs for New Construction in NC, Cost Effective Wall Systems that Meet NC Energy Code Requirements, Green Building for Building Professionals, and Building Energy Codes.

More information


East Coast Green - Sept. 16- 17

East Coast Green is held in conjunction with AIA-NJ’s annual Design Day event on Sept. 16 at which award-winning design projects will be selected in various categories. The conference will be preceded on Sept. 15, by a full day of LEED (Leadership in Energy and Environmental Design) workshops sponsored by the New Jersey chapter of the U.S. Green Building Council. A Green Building Expo featuring green building products and materials will also be held in conjunction with the conference.

The theme will be “Meeting the Architecture 2030 Goals.” Architecture 2030 is a U.S. based, non-traditional environmental advocacy group focused on protecting the global environment by using innovation and common sense to develop, and quickly implement, bold solutions to global warming.

More information




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