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Study: Most Toilets "Spray" Germs If Flushed with Open Lid

Posted by Christina B. Farnsworth

Sep 22, 2015 7:37:23 AM

Prepare to be grossed out. A Discovery Channel episode tests the truth of the toilet "spray" rumor, and finds it to be mostly true.

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Insulation: Don't Leave Your Home Without It

Posted by Green Builder Staff

Jan 21, 2015 2:33:40 PM

Know the Lingo

R-Value: A measure of how effectively a material resists heat flow. Thus, higher numbers are better. 

Batt: A length of insulation that is precut to fit certain wall cavity dimensions. Typically sold in a pre-cut roll.

Unfaced/Faced Insulation: Faced insulation (typically a fiberglass batt) includes a vapor retarder on the interior face that restricts movement of moist air into wall cavities. Unfaced is simply a batt without a vapor retarder.

Ridge Vent: An opening covered by a rainproof vent that follows the peak of the roof, typically required by code. Some insulating methods, however, negate the need for a ridge vent. Clear it with your local code official first.

Blow-In: Method of introducing loose fiberglass, cellulose or mineral wool to framing cavities or attic space, typically using a machine with an attached hose.

Blower Door: Equipment used to test the effectiveness of a home’s insulation and air sealing systems.

Stud Cavity: The space between the vertical members of a conventionally framed wood or lightweight steel home. Common stud spacings include 16” and 24” on center (of stud).

IF YOU'VE EVER opened up the wall of a home built before about 1950, you’ve probably been shocked to find little or no insulation—or at best some crumpled newspapers. And even the earliest serious attempts at insulation with fiberglass look quaint now. Cavities were often only partially filled. Water from outside often leaked in around windows and doors and damaged the insulation. Of course, homes were so leaky prior to the 1960s that walls dried out quickly, so mold wasn’t a big problem.

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Indoor Air Quality: Manage Air Flow and Materials

Posted by Green Builder Staff

Jan 14, 2015 2:29:00 PM

ONE OF THE CONFUSING CHARACTERISTICS of green building certification programs is the way they lump together two different aspects of building science: saving energy and keeping indoor air safe and clean. Is a green home one that saves energy, or one that has healthier indoor air than a conventional home?
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Flat Roofs Earn Their Keep

Posted by Dan McCue

Dec 30, 2014 1:23:00 PM

 

WHEN PAUL LEDMAN PAUSED TO CONSIDER THE ROOFING OPTIONS of the new, multi-family home he was building in historic Portland, Maine, the ultimate choice seemed like a no-brainer.

To the former New Yorker, who has developed several multi-family brownstone and commercial projects, a pitched roof would have just seemed odd for the three-unit home he was contemplating.

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Proper Installation of APA Rated Sheathing for Roof Applications

Posted by Green Builder Staff

Dec 11, 2014 11:41:28 AM

Check out this informative entry on sheathing for roof applications available on the APA builders' tips page. Downloadable pdfs on this and other subjects are available.

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The Dirty Truth About Outdated Wood Stoves

Posted by Green Builder Staff

Dec 8, 2014 5:59:00 PM

This snazzy infographic spells out the health and energy reasons that you should replace older wood stoves with new, certified models.

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The Promise of Good Ideas

Posted by Matt Power, Editor-In-Chief

Dec 6, 2014 5:21:00 AM

Before you say "nothing ever changes," here are five energy and water-saving innovations to be grateful for this holiday season.

EACH YEAR, we update and “remodel” our special Homeowner's Handbook for homeowners and would-be homeowners. (Free download available here). The publication isn’t just for the general public, of course. It’s a tool for green professionals: a free, easy-to-follow how-to guide that can be shared with clients and potential clients, so that they enter the building/remodeling process with a basic understanding of why green building matters—and which systems are critical to a high-performance home.

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Choosing a Wood Stove

Posted by Green Builder Staff

Dec 5, 2014 4:31:00 PM

OLDER, UNCERTIFIED wood stoves produce 30 to 50 grams of particulate per hour, contributing to asthma and a host of other health issues. The internal design of wood stoves has changed entirely since the EPA issued standards of performance for new wood stoves in 1988. Today’s wood stove models feature improved safety and efficiency; they produce almost no smoke, minimal ash and require less firewood.

Emission Limits for Wood Stoves.
EPA’s mandatory smoke emission limit for wood stoves is 7.5 grams of smoke per hour (g/h) for non-catalytic stoves and 4.1 g/h for catalytic stoves. Some newer stoves have certified emissions in the 1 to 4 g/h range;.

When comparing models, look for the EPA white label on the stove. A lower g/h rating means a cleaner, more efficient stove. Also check for safety labeling by the Underwriters’ Laboratories of Canada (ULC) or another testing and certification body.

Types of Wood Stoves
The two general approaches to meeting the EPA smoke emission limits are non-catalytic and catalytic combustion. Although most of the stoves on the market are non-catalytic, some of the more popular high-end stoves use catalytic combustion. Because they are slightly more complicated to operate, catalytic stoves are suited to people who like technology and are prepared to maintain the stove properly, so it continues to operate at peak performance.

Non-Catalytic Stoves. Three components make these stoves efficient: firebox insulation, a large baffle to produce a longer, hotter gas flow path and pre-heated combustion air introduced through small holes above the fuel in the firebox. The baffle and some other internal parts of a non-catalytic stove will need replacement from time to time, as they deteriorate with the high heat of efficient combustion.

Catalytic Stoves. These stoves produce a long, even heat output—thanks to catalytic combustion—in which the smoky exhaust is passed through a coated ceramic honeycomb inside the stove where the smoke gases and particles ignite and burn. All catalytic stoves have a lever-operated catalyst bypass damper, which is opened for starting and reloading. The catalytic honeycomb degrades over time and must be replaced; it can last more than six seasons if the stove is used properly. If the stove is over-fired, if inappropriate fuel is burned, or if regular cleaning and maintenance are not done, the catalyst may break down in as little as two years.

Sizing. Small stoves are suitable for heating a family room or a seasonal cottage. In larger homes with older central furnaces, you can use a small stove for “zone heating” a specific area of your home (family or living room). Medium stoves are suitable for heating small houses, medium-sized energy-efficient houses and cottages used in winter. Large stoves are suitable for larger, open-plan houses or older, leakier houses in colder climate zones.

Wood Matters. Dense or “hard” wood contains the most energy per cord and is the best choice for peak winter conditions. Burning softer woods during swing seasons keeps rooms from overheating. Regardless, wood should be dried and stored for at least two years before burning. Source: EPA

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Building Science: SIPs Go Up at Mariposa Meadows

Posted by Al Cobb, Guest Columnist

Nov 19, 2014 3:19:00 PM

Spending the last quarter-century in the SIP industry has given me the opportunity to meet a lot of individuals in the construction arena, and one of my most prized contacts is Mr. Green Builder himself, Ron Jones. When Ron presented his thoughts on the latest VISION House project at the SIPA Annual Meeting last April, my company PanelWrights was one of the first in line offering SIP design and installation services.

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Attic Caps: Fixing a Hole

Posted by Matt Power, Editor-In-Chief

Oct 9, 2014 3:24:00 PM

It seemed like everywhere I turned at this year’s International Builder Show, I cam across a new variation on an old idea—closing up the space above attic access stairs. While no one seems to have exact figures, third party testing suggests that some brands cut attic air infiltration by 70 percent.

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Using Building Science to Shave HERS Scores

Posted by Hilary Daninhirsch

Sep 29, 2014 10:55:08 AM

BUILDING HOMES IN accordance with RESNET standards is all in a day’s work for David Weekley Homes, whose corporate offices are in Houston. The company joined the green building revolution by connecting with Environments for Living (EFL), which uses concepts of building science (in partnership with the company of the same name) to build green homes.

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Double Zero: Net Zero Energy with an Eye Toward Water Conservation

Posted by Hilary Daninhirsch

Sep 26, 2014 12:24:00 PM

KB HOME RECENTLY constructed a home in Lancaster, California (in Los Angeles County), which earned the company RESNET’s award for Lowest HERS Index Score for a Production Builder. Dubbed the Double ZeroHouse 2.0, it’s not only net-zero energy, it also requires no freshwater for irrigation. Even without the SunPower solar PV system, this home achieves an impressive HERS score of 42.

Jacob Atalla, vice president of Sustainability, says that KB Home was the first homebuilder to sign up with RESNET as a RESNET Energy Smart Builder. The company has its own Energy Performance Guide, incorporating HERS principles, which allows homeowners to calculate the dollars they can expect to spend and save.

Atalla reported that KB Home obtained a HERS rating for all 7,000 of their new homes in 2013, and achieved its goal of increasing their energy efficiency by 3 percent. The average HERS score for homes built in 2013 was 65.

“On average, homeowners currently save $1,000 per year on energy bills compared to a typical resale home,” he says. “It’s a big value, and customers are looking for it.”

In fact, the HERS Index score is being added to many MLS listings; a home that has a very good (low) score gains an advantage over one that doesn’t, even if the homes share many other characteristics.

KB Home builds in communities across the country, from California to Florida to Maryland. The company chose to build the Double ZeroHouse 2.0 in Lancaster because the city strongly supports renewable energy. The high desert, drought-prone location also allowed KB Home to showcase their water conservation mechanism -  a new graywater recycling system from Nexus eWater. The system can treat up to 40,000 gallons of water a year for use as landscaping irrigation.

“We also used brand new technology—new to us—that contributed to lowering the HERS score in that house,” says Atalla. The Power-Pipe by RenewABILITY is a wastewater heat recovery device that takes wastewater from the shower drains, extracts the heat, then uses it to heat the new freshwater going into the tankless water heater. Atalla estimates the Power-Pipe saves approximately 10 percent of the energy spent on water heating.

As with all of their homes, KB Home focused on the building’s envelope and mechanics. The team insulated the attic at the roof deck, upgraded insulation in the walls, tightened air sealing of the house, upgraded windows to argon-filled units and installed a tankless water heater. Another “extra” was a smart garage with an electric vehicle charging station.

Atalla says that RESNET-certified HERS raters are usually on site twice—once during the framing and installation of insulation and then again at the end of construction. But because they were aiming for “double zero,” the rater partnered with KB Home early in the design process, helping to identify elements that could make the home more efficient and meet the net-zero-energy target, and visited the site more frequently, as well.


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This Free Concrete Calculator Estimates Slabs, Footings and More

Posted by Matt Power, Editor-In-Chief

Sep 20, 2014 7:43:21 AM

Here's a great one-stop concrete calculator for all of your footer, slab and foundation projects. Optimize your use of concrete and help reduce global CO2 emissions.--Editor

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