The most recent blogs at Green Building Advisor

Without Technical Assistance, Policy Efforts Fall Flat

Posted on June 10, 2011 by Peter Yost in Green Communities

From guest blogger Alison Corwin, New Ecology

How Is a Home’s HERS Index Calculated?

Posted on June 10, 2011 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

Anyone involved with the Energy Star HomesA U.S. Environmental Protection Agency (EPA) program to promote the construction of new homes that are at least 15% more energy-efficient than homes that minimally comply with the 2004 International Residential Code. Energy Star Home requirements vary by climate. program has probably heard of the HERSIndex or scoring system for energy efficiency established by the Residential Energy Services Network (RESNET) that compares a given home to a Home Energy Rating System (HERS) Reference Home based on the 2006 International Energy Conservation Code. A home matching the reference home has a HERS Index of 100. The lower a home’s HERS Index, the more energy efficient it is. A typical existing home has a HERS Index of 130; a net zero energy home has a HERS Index of 0. Older versions of the HERS index were based on a scale that was largely just the opposite in structure--a HERS rating of 100 represented a net zero energy home, while the reference home had a score of 80. There are issues that complicate converting old to new or new to old scores, but the basic formula is: New HERS index = (100 - Old HERS score) * 5. Index, a method of scoring the energy efficiency of a new or existing home. A Web page maintained by the state of Arkansas, for example, explains that the “EPA requires a house qualifying for Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. to be built with best practices, tight ducts, and at least 15% more energy efficient than code as shown by a HERS Index score of 85 or less as determined by a HERS Rater.”

How to Sell Green Upgrades: Exhaust Fans

Posted on June 9, 2011 by Michael Strong, LEED Associate, CGP in Business Advisor

You know every little bit helps. Whether you are helping a customer select a higher quality bath exhaust fan or you are making more money on the fans you sell, it all adds up, benefiting you and your customer. So don’t ignore the following opportunity to affect positive change with a small but important product — and make a couple of extra dollars along the way.

Net-Zero Homes, Part 1

Posted on June 8, 2011 by Christopher Briley in Green Architects' Lounge

You can also subscribe to the Green Architects' Lounge on iTunes. That way, you'll never miss a show—and it's free.

Helping Architects, Contractors, and Homeowners Get Greener

Posted on June 7, 2011 by Carl Seville, GBA Advisor in Green Building Curmudgeon

One of the side benefits of being on a long bus trip like the one to the Koetter millwork plant is that people talk quite a bit. Not being particularly shy, I talked a lot about high-performance homes and green building when given the opportunity. Conversations often started out with the “it’s so expensive” or “it’s too hard” sort of comments, which provided me the opportunity to dispel those myths — which I believe I did with occasional success.

‘Superwindows’ To the Rescue?

Posted on June 7, 2011 by Tristan Roberts in Energy Solutions

As I've said before, windows are a silent but very high-tech part of our buildings. The advances in glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill. in the last 30 years have been phenomenal. Will windows keep getting better and better with no end in sight?

Can a High-Performance House be Livable, Too?

Posted on June 6, 2011 by Scott Gibson in Q&A Spotlight

Readers who post a question in GreenBuildingAdvisor’s Q&A forum typically look for advice on very specific building problems. Whether the challenge is detailing a rainscreenConstruction detail appropriate for all but the driest climates to prevent moisture entry and to extend the life of siding and sheathing materials; most commonly produced by installing thin strapping to hold the siding away from the sheathing by a quarter-inch to three-quarters of an inch. , selecting windows with the right solar heat-gain coefficient, or using thermal massHeavy, high-heat-capacity material that can absorb and store a significant amount of heat; used in passive solar heating to keep the house warm at night. to store solar energy, the focus is usually narrow and technical.

New Air Sealing Requirements in the 2009 International Residential Code

Posted on June 3, 2011 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

One of the most cost-effective ways of lowering residential energy costs is to reduce a home’s air leakage rate, so it makes sense for energy codes to ratchet up air-sealing requirements. The latest (2009) version of the International Residential Code does exactly that.

Using Window Stickers to Get What's Right for Your Climate

Posted on May 31, 2011 by Tristan Roberts in Energy Solutions

Have you ever found yourself picking a sticker off a building product or material from the store, and wondering, why did they put the sticker here? I have often had this thought with everything from stovepipe to plumbing fittings, but the classic example in the building world is probably windows.

What's the Best Way of Dealing With a Leaky Crawl Space?

Posted on May 31, 2011 by Scott Gibson in Q&A Spotlight

Morgan Martin’s dilemma is what to do about the crawl space beneath the house, identified in a recent energy auditEnergy audit that also includes inspections and tests to assess moisture flow, combustion safety, thermal comfort, indoor air quality, and durability. as a source of air leaks and energy loss.

The joist bays above the crawl space have been insulated with fiberglass batts, but the subflooring has not been air-sealed. A local green building company recommends removing the batts and taping and caulking all the gaps in the floor (that is, the crawl space ceiling).

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