Comments on: A Home Energy Rating Is Not an Award

By: David Butler

David Butler — Sat, 11 Aug 2012 06:17:27 +0000

Matthew C wrote:
Matthew C wrote:
> In many cases, they are... only rating their house plans and specs

The implication is that these homes are not being confirmed through mandatory field inspections (see my previous comment). If so, there's a complaint procedure for situations like this. However, if you just meant these homes are not being DB/BD tested, then this is supported by the HERS Standard. The default leakage rate would apply.

There seems to be a lot of confusion on this point. After hearing about homes in a western city that were not being tested, I studied the standard carefully and at best, it's ambiguous on this point. So I checked with several HERS providers and all said they require DB/BD testing (for a HERS certificate). However, none could point to such a requirement in the Standard. The fact that some providers (apparently) do not require DB/BD testing means that not everyone is playing by the same understanding of the rules. Not good.

So I raised this question in the LinkedIn RESNET.US group last month and Steve Baden responded. He confirmed that the HERS Standard doesn't require leakage tests. But he added that most builders elect to have their homes tested since the default leakage rates impose a serious penalty on the HERS Index. More likely, it's because they nor their providers are aware it's optional. The reality is that for builders who are at the margin, the impact may be as small as 2 points, depending on the particulars.

The pertinent chapter is currently undergoing revision for ANSI compliance, so hopefully this can be resolved. Steve Byers, who is a provider and is on the RESNET Board, is on top of this.

By: Allison Bailes

Allison Bailes — Tue, 19 Jun 2012 23:19:32 +0000

Matthew C.
Matthew C.: I just recalled that part of the discrepancy is probably due to ENERGY STAR homes going through the prescriptive path (the Builder Option Package, or BOP) as well.

By: Allison Bailes

Allison Bailes — Tue, 19 Jun 2012 23:17:41 +0000

Matthew C.
Matthew C.: Oops. I had my hammer out and thought you had a nail. (I.e., I was addressing a different issue than the one you raised.) My guess on that discrepancy is that maybe they didn't count sampled homes as getting a real HERS Index, even though they do get a worst-case Index. I wasn't involved in the mid-'90s, so I don't know if and how many homes got the ENERGY STAR label without a HERS rating, as Kim suggested.

By: Allison Bailes

Allison Bailes — Tue, 19 Jun 2012 23:12:40 +0000

kim s.:
kim s.: Excellent points. If you want to see how cost effective a measure is, it helps to apply it in the correct climate zone and for the correct conditions.

Matthew C.: I guess you didn't see my tweets on that topic this morning. The mathematical side of me rages against someone claiming to know which home was THE millionth home certified when there are so many open channels for certification. I think it's great to celebrate milestones, but to pick one house out of the thousands that were certified at about the same time is definitely a stretch.

By: kim shanahan

kim shanahan — Tue, 19 Jun 2012 23:11:42 +0000

Energy Star for homes
Energy Star for homes preceded HERS ratings and thus had no requirement for a HERS rating at the beginning of the program.

By: Matthew Cooper

Matthew Cooper — Tue, 19 Jun 2012 22:51:38 +0000

I have yet to have anyone
I have yet to have anyone explain how it is the the one millionth ENERGY STAR new home was certified in 2009 yet supposedly the one millionth HERS index was just calculated two months ago.

By: kim shanahan

kim shanahan — Sat, 16 Jun 2012 02:23:02 +0000

At the recent NAHB Spring
At the recent NAHB Spring Board Meeting, the NAHB Research Center made a presentation to one of the subcommittees of the Construction Codes and Standards Committee on a cost benefit analysis of the 2009 IECC versus the 2006 IECC. Their conclusion was that it pays for itself within seven years and was therefore reasonable. Then they compared 2012 IECC versus 2009 and deemed the payback to be something like 20 years and therefore unacceptable. The point of the research was to provide ammo for those who may be trying to convince local and state code adopters that the 2012 IECC was a code too far.

The problem with the NAHBRC model, was its "grossness". In an attempt at simplicity, they based their conclusions on an average house, in an average climate zone, in an average moisture zone, with average construction costs, average occupant loads, average utility costs, and on a prescriptive basis only.

So when somone tries to use it as "proof" in any given locality, local administrators will be able to legitimately counter that the data does not represent local conditions, (unless they are truly "average"). And even then a builder could probably follow a creative performance path, get a HERS rating equivalent to the prescriptive path assumption, and bust the NAHBRC construction cost numbers.

I offered the suggestion (as the Executive Officer Liaison to the committee) that perhaps RESNET should be solicited as a research partner. Having recently completed their millionth HERS rating, they should have the potential to glean and provide an immense amount of data for every climate zone, every size home and with every imagineable utility cost. Competent raters can also calculate the presumed energy cost in dollars, BtUs, therms, etc.

RESNET cannot provide the cost of construction or energy efficiency upgrades, nor can they accurately predict occupant behavior, but they certainly could provide more accurancy and relevant data than the woefully inadequate conclusions reached by the NAHBRC.

RESNET has its place as the dominant national measurement tool. Hopefully they will recognize their potential role as a national data collection service and begin to help influence local and national policy directives.

By: Bob

Bob — Fri, 08 Jun 2012 06:23:20 +0000

Builders can "put their
Builders can "put their money where their mouth is" by installing smaller HVAC units. How confident ARE you that it's insulated properly? Care to do 1,000 sqft per ton?

By: David Butler

David Butler — Thu, 07 Jun 2012 22:09:43 +0000

@Matthew, have you actually
@Matthew, have you actually seen an MOU that allows for unconfirmed ratings from plans? The reason I ask is because the HERS Standard specifically requires all ratings to be confirmed. And as far as I know, there's no proposed or in-process amendment that would change this, at least none are posted on the RESNET website.

"102.1.4.1 Ratings from plans. If the home energy rating Provider‘s program provides for ratings by from plans, the rating be labeled as from plans. Such ratings may be used to demonstrate energy code compliance or programmatic qualification but must be confirmed through a field inspection upon completion of construction."

By: Allison Bailes

Allison Bailes — Thu, 07 Jun 2012 19:44:41 +0000

Matthew C.
Matthew C.: Wow! I guess I haven't read the MOUs closely enough. Marketing a HERS Index from a projected rating sounds almost deceptive. Any home builder doing that could be setting themselves up for legal action.

TC Feick: Yes, there's a whole lot of education that needs to happen in the construction, remodeling, and home improvement industry. And speaking of setting thresholds, there's been a really good discussion of this very topic related to the question of, What would it take to build a Pretty Good House? Have you seen that?

Debbie: The answer to your question about the HERS Index for ENERGY STAR Version 3 is that there isn't a single number anymore. Instead, the folks at ENERGY STAR decided on a 'variable HERS Index target,' which depends on the house you're rating.