Favorite Quotes

"All of man's works intrude upon nature - It is man's obligation to intrude harmoniously."

Alden B. Dow, c. 1958

What Green Building Certifications are you interested in?

Tuesday, May 17, 2011

A HERS Score of -1!!!!!

More Exciting news from Arn McIntyre of Ferris State University Energy Center (Our Green rater) and Habitat for Humanity of Kent County our "335 Freyling Place Net-Zero Energy Project" just received a preliminary HERS score of -1. This is possibly the new lowest HERs score in the State of Michigan. It's all preliminary but we'll have firm results this fall upon completion:

  • Area of conditioned space 2904
  • Btu/ sf/ hdd .51
  • Peak heat loss design 11.6 kbtu/h
  • Shell area: 5677
  • ACH 50 4.23
  • Total cfm of blower door 400cfm
  • Date of blower door test 4/8/11
  • Test performed by Arn McIntyre
  • Electrical kwh per year 28.6mmbtu/yr
  • Fossil btu per year 20.2mmbtu/yr
  • Renewable Elec produced per year 33.5mmbtu/yr
  • HERS index -1
See the post below for more information on what a HERs score is.

As I mentioned in the post below, I am a firm believer in Kaizen ( A Japanese philosophy), or continuous improvement. I am continually studying the building science of homes to make improvements to them so they are as energy efficient as possible within their budgets. So even though a HERS rating of -1 is the best we have achieved so far our goal are to continually improve upon that score with the ultimate goal of a HERS score of even a larger negative score.

Friday, May 13, 2011

A HERS Score of 12!!!

Exciting news from Mike Holcomb of Energy Auditor General (Our LEED for Homes rater) and Dan Vos of Vos Energy Concept our "River Escape project" just received a HERS score of 12. This is the lowest score Mike Holcomb has every tested as a rater in Michigan and possibly the lowest score in the State of Michigan. This extremely low HERS score means that our "River Escape" project should easily be projected at the "Platinum" Level under the LEED for Homes program. Both Dan and I are very excited about this news.

What is a HERS, or Home Energy Rating System score? Well it is basically a rating of how energy efficient a home is based on a number of things, including a blower door test, the HVAC system, energy usage, and so on. The HERS rating is what is used to qualify a home for the Energy Star Rating. The rating is based off of a standard new home built to code that was rated originally tested and used as the test case with the score of 100. A typical older home has a HERS index of 125-150. Most homes that qualify for Energy Star homes must have a HERS rating of 85. That means that those homes are 15% more energy efficient than the test house. This is really good and a step in the right direction. Most of our homes have been scoring in the 50's, which is where we would expect the to fall. That HERS score would qualifies our homes as 5 star+ in the Energy Star rating system. The "River Escape Project" came in at 12 (lower the better) making it 88% more efficient than a new home built to code.

Based on their Home Energy Rating System (HERS) scores, the average home certified under LEED for Homes since its launch in February 2008 is predicted to use an estimated 30-60% less energy than a comparable home built to International Energy Conservation Code. Based on the average HERS ratings for each level of LEED certification, these homes could potentially see energy reductions of:
  • Certified: Up to 30%.

  • Silver: Approximately 30%.

  • Gold: Approximately 48%.

  • Platinum: 50-60%.

As many know, I am a firm believer in Kaizen ( A Japanese philosophy), or continuous improvement. I am continually studying the building science of homes to make improvements to them so they are as energy efficient as possible within their budgets. So even though a HERS rating of 12 is the best we have achieved so far our goal are to continually improve upon that score with the ultimate goal of a HERS score of 0 or a negative score.