Is anyone aware of HERS tracking 5 years or more after new construction?  I am looking for a study that may provide how valid the HERS rating might be 5 years or more after new construction.  Comparing the original HERS Rating to one later assuming no changes have been made to the house would provide credibility of the Index after new construction.  A representative of Fannie Mae questioned using the HERS Index after new construction.  It is hard to believe this type of tracking is not being done somewhere to give answers to the secondary market and public.

If changes to the structure are made or maintenance is not as envisioned, it would explain a difference. Any information you may have would be helpful.  Including the HERS Rating in the MLS and other databases going further presents this question that begs for an answer.

Tags: Energy, HERS, Index, MLS, Rating

Views: 344

Reply to This

Replies to This Discussion

Michael,

I understand your point and I have no problem with the study you reference other than it does not answer the secondary mortgage market question as to prove the HERS Index is still valid 5 yrs or more out from new construction.  They are looking for comparison using HERS Index at new construction and HERS Index 5 years or more out.  The comment regarding the utilities is there are too many variables to consider it a reflection of how relevant the HERS Index may be 5 yrs or more out.  It is a battle I am trying to overcome.

The problem you are trying to solve is reconciling the bias and (mis)perceptions of appraisers and the real estate industry with the intent of REM/Rate (HERS software) as an energy modeling tool.

As I said before, the HERS Index Score of a newly constructed house is fairly static and durable.  If there are no substantial changes to the home, there is no need to keep verifying it.  If the specs of the home are the same when it was constructed:  No HERS change.  Small variances in leakage test numbers don't move the number much either.  I have personally seen this to be true on literally thousands of before-and-after HERS ratings when I was QA for a utility-sponsored energy audit and improvement program.  Improvements don't move the needle as much as you think they would.

I also verify homes for LEED certification.  If a home is LEED certified when constructed, does it need to be recertified every time it goes on the market?  The answer is: NO.  LEED certification is a stable selling feature of the home.  The HERS Index SHOULD be thought of in much the same way for homes that were rated at construction.

This is why there is not much "out there" to answer your question.  The vast majority of the home building industry isn't interested in spending the $$$ on validation studies because they have little monetary stake in resale value once the house is sold to the 1st home buyer.

Because the HERS index is also used by energy performance contractors as a way to validate their efforts on existing homes, there is a perception that a HERS score is a highly elastic, ever-changing metric that must be continually redone to be valid.

From all I have gathered, the appraisal industry is still behind the curve and has not yet fully come to terms with how they are going to quantify the HERS metric, and other green home features, into their assessment process.

It appears they may have to conduct some primary research to figure that out!  :-)

Let me know if I can help...

Craig

EnergyIQ-USA.com

Craig,

The secondary mortgage market - Fannie Mae questioned the use of a HERS Index after new construction.  The questions are not out of bias from the appraisal industry but out of defense from the secondary market.  This came up at the Green Mortgage Appraisal Roundtable at the White Conference on March 11th.  No one in the room could answer Fannie's question on reliability of the HERS Index 5 yrs out or longer.

I've sent this directly to Sandra but for those following this thread Building Science Corp. provided a link to a study regarding air tightness over time, which to me would seem the only real variable to a HERS score in a 5-10 year time frame (absent home modification) that might cause a change in a HERS score.

The only research that I know of that looked at air tightness results ten years later was done by Gary Proskiw.

http://web.ornl.gov/sci/buildings/2012/1998%20B7%20papers/072_Prosk...

Sam Rashkin also indicated that LBNL is currently doing a study on air tightness over time as well.

Jeff,

Thank you for your prompt reply with the link to a study that is certainly what I need.  I look forward to seeing the LBNL research to add additional support for reliance on this method of testing the energy efficiency of a building.  I hope more studies will be done periodically to allow us to have solid support for using this Index.

This should be done. We are working on it now.

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.

Latest Activity

Bill Midgett is now a member of Home Energy Pros
2 hours ago
Hal Skinner replied to Richard Beyer's discussion Spontaneous Combustion and Flash Fire regarding Spray Foam Insulation
"Richard, here is something else that might be pertinent. In my hundreds of conversations with our…"
21 hours ago
Trip posted a discussion

Starting a Home Weatherization Business. Considering it...

I am considering starting a home weatherization business. (I live in Southeast Alabama)  Currently…See More
21 hours ago
Jim Gunshinan commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"To all, one thing I don't lack is advice from the experts! Thanks for the input, challenges,…"
22 hours ago
tedkidd commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Jim, I'm glad you are open, that's great!  We all learn best when we are open! The…"
23 hours ago
David Eakin commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Jim, Well, as the editor of Home Energy you should already know that the order of remediation is…"
23 hours ago
Greg Labbe posted a blog post

Technical Tape Desecration

Lets face it – building science is pushing the performance of adhesive tapes to a new levels and…See More
yesterday
Stacy Hunt posted an event

High Performance Enclosure Strategies: Part II, New Construction at Online

August 13, 2014 from 1pm to 2:30pm
Please join the Building America Program for our free webinar: High Performance Enclosure…See More
yesterday
Richard Beyer replied to Howard Katzman's discussion UV lights on filters
"Howard, There are numerous manufacturer's who swear these systems work and then you have the…"
yesterday
Christopher Morin posted a blog post

How do You Test a TXV?

  Thermostatic Expansion Valves (TEV or TXV), one of the most popular metering devices for…See More
yesterday
Howard Katzman posted a discussion

UV lights on filters

I recently saw UV bulb installations in 2 HVAC systems in a home. Each system had the Lennox…See More
yesterday
Don Fitchett joined Michael Stuart's group
Thumbnail

INFRARED THERMOGRAPHY USERS

This group is dedicated to knowledge sharing and discussion of infrared thermography for building…See More
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service