www.energystarhomesamerica.com

Issue 1 Volume 3

January 31, 2005

Adoption of the National Home Energy
Rating Standards
By Kelly Parker, Professional Engineer
The Residential Energy Services Network (RESNET) Standards Drafting Committee was appointed in 2001 to review RESNET’s Mortgage Industry National Home Energy Ratings Standards and draft proposed amendments to the standard. After three years of research, deliberations, vetting and public review, the committee unanimously recommended that the RESNET Board of Directors endorse the set of enhancements. 

The proposed amendments were developed through a three year process that was agreed upon by the RESNET Board. This process included:

* Publicly soliciting recommendations for proposed changes to the standard in 2001
* A consensus process in which the drafting committee developed the proposed amendments to the national standard 
* An aggressive vetting and education effort to obtain input from the key stake holders of ratings services 

Groups included were:
    
     - National Association of Home Builders
     - RESNET Board of Directors
     - RESNET Membership
     - U.S. Department of Energy
     - U.S. Environmental Protection Agency
     - National Association of State Energy Officials
     - North American Insulation Manufacturers Association
     - Building America Team

The enhancements fall into six basic categories:

* Revision of the Reference Rating Home
* Enhanced Quality Assurance
* Incorporation of Lighting, Appliances & On-Site Energy Production
* Technical Enhancements
* Program Administration Enhancements
* Rater Training & Certification Enhancements

In the area of technical enhancements, there are several changes that will significantly affect builder requirements.  One of the most prominent changes is in insulation inspections. Inspectors shall rate insulation installations as Grade I, II, or III according to the enhanced guidelines which are summarized as follows:

Grade I: describes insulation that is generally installed according to the manufacturer’s instructions.  To attain the Grade I rating, insulation must be enclosed on all six sides and shall be in substantial contact with sheathing material on at least one side. 
Grade II: describes insulation with moderate to frequent installation defects. Gaps and spaces running clear through the insulation may amount to no more than 2% of the total surface area.
Grade III: describes substantial gaps and voids that amount to no more than 5% of the total surface area.
(More than 5% missing insulation shall be measured and modeled as separate, uninsulated surfaces.)

Also, floor dimensions shall now be measured in accordance with ANSI Z765-1996.

The effective date of these amendments will vary between April 1, 2005 to January 1, 2006. Ask your market manager for further details, or for more information, please visit www.natresnet.org.

The result of this process is a set of enhancements to the national home energy rating standards that are technically defendable and do not present an undue burden on the rating industry or the clients of its services. The result enhances the credibility of our industry by moving it forward into the 21st century and setting a high standard of quality.

What is the Whole Building Approach?
by Jennifer Boyle

   There are a lot of terms flying around today used to describe environmentally considerate design and building practices... green, sustainable, and eco-friendly are just a few.  While those are some of the general terms, builders are being increasingly exposed to their own new set of terms... whole building approach, the house as a system, the systems approach…etc.  These all basically describe the same thing: designing and building a structure where every small decision is made in the context of the whole.  Classic examples include site orientation and window selection: the orientation of the structure on the site will determine heat gain and the feasibility of passive solar heating while the window selection will also affect these as well as the size of the HVAC system and energy consumption.

The whole building approach includes all members of a design and construction team from the beginning of the project. While this is ideal and not always possible, understanding that buildings function as a system will only make you an asset to any team of which you are a member. 

The marketplace has been flooded in the past few years with literature and guidelines for environmentally considerate design practices, a result of the relative newness of these concepts in the mainstream.  However, most of these guidelines address the same core principles. The Sustainable Buildings Industry Council (SBIC) has recently released the 4^th edition of their Green Building Guidelines. As determined by the SBIC, there are some basic issues to consider when using the whole building approach: site selection and orientation, the building envelope (is it durable and easy to assemble and possibly disassemble?), energy use, water conservation, resource efficiency of materials (where did they come from and what is their environmental impact?) and indoor environmental quality.  Knowledge about and consideration for these key elements is an excellent foundation for building a better quality home. For more information about these specific topics, visit www.SBICouncil,org or to obtain a copy of the Green Building Guidelines, visit www.builderbooks.com

Inspector’s Corner
By: David B. Walker – National Operations Director

“To Face or Not to Face”

    No, this isn’t going to be an article on Shakespearean Building Science. This article is actually designed to discuss one of the most necessary products used by construction professionals in our modern era – “Insulation”. Since the advent and advancement of mechanical equipment designed to keep us comfortable in our homes, insulation has made the sustained effort to supply us with the ability to keep this expensive privilege under control.

  Insulation is designed to resist the flow of heat. Many times this is referred to “Heat Loss” and “Heat Gain”. Heat, being a form of energy, has the ability to move towards cooler areas. This transfer of heat is what insulation works against. When heat flow is reduced energy costs are also reduced. So this is why the proper installation of insulation is so important. The key here is to not just save cost, but to also save energy.

  There are various types of insulation on the market today. But, for the sake of this article we’ll concentrate on fiberglass insulation. Batts and rolls are the most commonly used fiberglass insulation – especially in wall cavities. “Faced” insulation, or insulation with a vapor retarder is designed to resist the movement of moisture vapor to cold surfaces where it could condense to liquid water. “Un-faced”, or batts and rolls without the vapor retarder, are becoming popular in the “Hot/Humid” climate. This is due to the usage of a vapor material or sheathing used on the outer part of the wall, becoming an “air block” as well as a vapor retarder.

  It is important to choose the proper insulation when constructing a home. Each component is vital to the other, and can adversely affect the “house as a system”. Having insulation “sandwiched” between two vapor retarders will and could eventually trap moisture inside the wall cavities, causing great damage. Most codes assert the fact that the vapor retarder should be placed on the “warm-in-winter” side of the wall. However, in the Hot/Humid climate, the amount of “heating degree days” are minimal, therefore the vapor retarder is primarily applied to the outer wall. Checking local practices and or building codes are essential.

  There are those who choose to use the faced insulation. This is suitable as long as the moisture does not become trapped within the wall cavity. Therefore, making sure the sheathing material is not considered a “vapor retarder” or “vapor barrier” is vital. The most important factor is to make sure the insulation is installed correctly, whatever is chosen. Both types of batt insulation are suitable, just be sure you understand the properties of the type you use. Because most “faced” insulation is “inset stapled”, (stapled approximately a quarter inch inside the stud) the vapor barrier material is not continuous. Therefore it does not serve directly as a complete vapor retarder. Un-faced insulation is usually wider than standard insulation batts in order to allow the insulation to stay within the cavity, and allow for the insulation to complete the thermal boundary. These batts are called “friction-fit” or “pressure-fit”. Of course, here is where it is necessary to know whether or not you have some sort of continuous vapor retarder installed on the outer portion of the wall. Whatever type you choose, be sure that you fully understand the nature of the materials. A good resource concerning vapor retarders can be found in the ASTM handbook, under ASTM C 755. It says “...a material that adequately retards the transmission of water vapor under specific conditions”. The bottom line is to keep the moisture “vapor” from cold or cooler surfaces where it might condense.

  As you can see, there is a lot to know when insulating a home. Because of the higher standards of home construction we follow today, it seems that educating ourselves about the materials we use is an important factor. If you would like more information concerning insulation, log on to the NAIMA website – (North American Insulation Manufacturers Association) @ naima.org, or call us @ 1-888-488-0206 or visit our website – GWSSI.COM.

Announcements...

Attention Builders:
The 2005 RESNET Building Performance Conference is upon us.  The conference is scheduled for February 28 through March 2, and will be held at Plaza San Antonio.  This year’s theme is “Prospering in Changing Times” and will include an ENERGY STAR Builders Track.  The sessions offered within this track are as follows...

 “A New Environment for Builders” - changes to IECC
“Giving Credit to Quality Installation”
“Home Energy Ratings and Green Buildings” - USGBC & LEED
“Where Do We Go From Here?” - energy efficiency tax credits
“What it All Means” - changes to the rating score in 2006
“Let the Word Go Forth” - marketing
“New Business Opportunities with ENERGY STAR”
“Selling a Higher Quality Home”
“Defining Adding of Value Rating Services to Builders”
“Zero-Energy Homes Performance”

For more information, go to the RESNET site at www.natresnet.org
We hope to see you there!

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