Comments on: Aspen, Colorado Dumps Energy Rating Index

By: Matt Turner

Matt Turner — Fri, 14 Dec 2018 06:31:06 +0000

The heating and cooling
The heating and cooling capacities will exclude the use of heat pumps, which seems counter productive if the goal is energy efficiency. They need to complicate the simplified code by waiving the cooling limit for homes using a heat pump.

By: Ren Anderson

Ren Anderson — Wed, 25 Jan 2017 14:13:49 +0000

Regards to my friends in
Regards to my friends in Aspen, but the devil is always in the details.

I certainly agree that you can hide the details as has been done by adopting section R406.

I don’t agree that R406 makes life simpler, except on paper. It is still just as hard to build a reliable high performance home in Aspen’s climate and requires just as many validated load calculations to confirm that you have reached that performance level today as it did before R406 was adopted.

By: Smita Thomas

Smita Thomas — Wed, 25 Jan 2017 13:18:01 +0000

Interesting and well
Interesting and well explained. Thank you! Will be sharing with my EDGE green buildings team at IFC working on code work in developing countries.

By: kim shanahan

kim shanahan — Tue, 24 Jan 2017 22:40:21 +0000

The advantage of ERI versus
The advantage of ERI versus “performance path” is that the ERI can factor other things besides the envelope. It is especially confusing because people choosing the ERI path believe, correctly, that they are following a “performance path”. Better to call the performance path the “whole-house UA trade-off” path, since neither it nor the ERI guarantee performance at all, they only predict performance. Being able to account for mechanical equipment, appliances, light bulbs, orientation and source energy, none of which are captured in the “performance path”, is a real benefit to the builder seeking code compliance with complex client and architect-driven projects. Furthermore, if we actually believe we will have codes someday in the future that mandate net-zero energy homes, we will only be able to accomplish that with an ERI requirement that allows for all manner of inputs. A non used BTU is a non-used BTU whether it comes from a solar panel or a tight envelope. Yes, the envelope is the first place to find the cost effective saved BTU, but we will never create a prescriptive path that will get us to zero unless the prescriptive path is one that simply says “Get a ERI of zero”

By: Robby Schwarz

Robby Schwarz — Tue, 24 Jan 2017 19:03:34 +0000

The issue I see here is that
The issue I see here is that the ERI path is significantly burdensome for a builder. In essence the builder has to do much more to comply with the ERI path than they would have to do to comply with the prescriptive path or the performance path. So, I do not believe that the ERI path will be widely used regardless unless jurisdictions weakening the pathway during the adoption process which I don’t think they should do. As a byproduct of the Simulated performance path builders should be getting a HERS Index so they should have an understanding of what the ERI of their houses are while using a pathway that allows them to figure out the most cost effective way to meet the intent of the code. The issue that I see here is that Aspen did not adopt the flexibility already built into the code. The code has the ability to help builders build homes that perform really well if jurisdictions would adopt it as written. There is no way for the Department of Energy and others to understand the impact of a code on the efficiency of house in relation to other code when significant amendments are made to the code. So, adoption and enforcement become the big issue. Offering additional flexibility, as Aspen did, might be fine but where is the data that demonstrates that the performance of their new section R406.1 is equal to the performance of the 2015 IECC as written. It might but it might not? I think a big driver here is still first cost vs cost of ownership and a builder driven perceptions of cumbersome code processes that they perceive do not add value. People who do code compliance work using the performance or ERI pathways need to ensure they fully understand the code and all that it takes to inspect and enforce. For example, the ERI path requires much more than just an ERI score to meet the intent of the code. If everyone, from code officials, to builder, to raters, do not understand that, then the additional value of the process is very difficult to justify from an economic or code and building performance perspective. Value is not in the ERI itself, the value is in the process of evaluating a house that the ERI or simulated performance path imposes on the house to ensure that the house works, and that mainly comes from ensuring that the mandatory aspects of the code are carried out well.

By: Terje

Terje — Tue, 24 Jan 2017 18:37:50 +0000

If my own HERS rated house is
If my own HERS rated house is anything to go by this seems like an improvement. My house meets none of these requirements listed above. And when the HERS rater just rubber-stamps whatever the builder throw up, it give little credibility to the rating. Like did nobody notice that the Manual J has the front door pointing north but it is actually pointing east....did he measure the airflow in the ducts? Because supply/return is less than 800CFM on a 3 ton system....and I could go on and on. I truly regret spending money on a Energy Star home. And not to mention there is a whole neighborhood with houses like mine.

By: Kim Shanahan

Kim Shanahan — Tue, 24 Jan 2017 16:51:32 +0000

Ken is right, they should
Ken is right, they should have kept the ERI/HERS as an option. The problem with stair-step codes is scale. How many BTUs required for a 1500 square foot home? 64,000 or 48,000? HERS ratings can account for the nuances.

By: W. Blake Talbott

W. Blake Talbott — Tue, 24 Jan 2017 16:00:09 +0000

The issue for all of Aspen's
The issue for all of Aspen's code options as well as the IECC is confirmation and accountability of results. As an Architect, HERS blower door tests important since they verify the design and systems are working appropriately. If the envelope is not functioning properly neither do the systems.

By: Ken Riead

Ken Riead — Tue, 24 Jan 2017 14:55:39 +0000

What I don't understand is
What I don't understand is the notion of 'dumping' one for another. People put in a lot of work to develop codes in the first place and if Aspen decides they have a better method then that is absolutely fine. What bothers me greatly is that they don't accept the ERI method at all. Why not allow the ERI to stand if builders want to use it and accept the simplified method in lieu of? Other professions don't seem to have this problem that I know of. How about if we do away with appraisers and use simplified valuation appraisals based on size, type, usage and age of the building? Why bother with requiring an engineer's stamp on plans and blueprints instead of just requiring that the plans be on a certain size of paper with acceptable colors of ink? Appraisers and engineers are required because they provide valuable, needed services. I suggest that raters also provide valuable services that cannot be replaced by a checklist.