Simple box model

First of all try to understand why you are doing this and then examine what makes sense for your project. Since it is existing you already know you aren't going to examine parameters associated with that. So what variables might make sense for the project given the scope of work? How can this model inform the design or the OPR performance targets or the project's energy goal for Optimize Energy Performance?

There is no set way to examine parameters. I have seen models that start with the highest possible level of energy efficiency and then remove strategies. I have seen it work the other way around. You could examine each individually and then as combinations. You could examine them collectively to evaluate the possible interactive effects of different strategies. However makes sense for your project as a guide to assist in informing design decisions and building performance is what you should do.

Since energy modeling during design is always a relative comparison, you do need some sort of baseline for comparison. The baseline can be of your choosing. Maybe it is Appendix G, maybe what the owner would normally build, maybe a specific EUI your project is targeting, etc.

The whole purpose of this credit is to get the design team talking about these issues from the beginning of design.

Quick follow up to this: The language of the credit says "Assess at least two potential strategies associated with the following:" Then lists 7 categories. Does that mean that you need a minimum of 14 box model iterations? Or would that be two total box model iterations with the 7 categories serving as starting points for discussion?

AT LEAST two strategies from the 7 categories. So the minimum is two. For most projects if you understand and embrace this analysis as a means to inform the development of the project's design you will likely be evaluating more than two.

Can I just double check this?  The reference guide text is ambiguous and could also be interterpreted that you should "assess to potential strategies asscoiated with each of the following".  (Although it doesn't say each you could read it like that)

Furthermore, the Integrative Process Worksheet states:

"Describe at least two potential load reduction strategies that were assessed for each aspect through simple box energy modeling before the completion of schematic design."

This implies that each of the 7 aspects should have 2 strategies assessed, i.e. 14 model iterations, doesn't it?

Has anyone been through the review process with only 2 strategies assessed?

Getting hung up on the number of strategies assessed is just simply missing the whole point of this credit. Do some analysis that further's the interest of the energy performance of the project. Again this should result in your analyzing more than 2 strategies.

We have already done an analysis looking at the 5 strategies which seem most relevant for improving the energy performance of the project, and have implemented some of the proposed solutions, so we have no problem with with meeting the intent of the credit.  Our concern is that a reviewer will follow the letter of the requirements that we have not assessed "at least two potential load reduction strategies for each aspect" and not approve the approach even if it is in line with the intent.

But you don't think that is likely?

My understanding is that the reviewers are not looking for a minimum number of strategies that were analyzed.

Hi gentlemen,

FYI, we did get a very specific comment on our IP worksheet about not including two load reduction strategies for the programmatic and operational parameters despite the fact that we actually did evaluate DCV and DOAS as operational parameters. DOAS helps reduce the operation hours of heating and cooling by letting it cycle when needed. The DCV strategy also reduces operating hours for the DOAS by allowing the ventilation to be at minimum when the spaces are unoccupied. We had to go to post review call with this and will have to provide more narrative trying to explain why these measures that we evaluated should be considered the kind of evaluation they are looking for.

Many thanks for the feedback Michelle!  So it seems like some reviewers may get hung up on the two strategies requirement?  I guess one solution is to go with LEEDv4.1 where they have removed the "two strategies" requirement, but otherwise it seems safer to make sure that 2 strategies are asessed for each aspect, i.e. 14 in total?  Feels like overkill given that some of the strategies are likely to be unrealistic to implement with these constraints, but if thats what the requirements say...

Seeing as this is clearly open to interpretation, does anyone know if it is possible to get an addenda or correction in the reference guide to clarify this without going through the CIR route, so that both reviewers and APs know how to interpret this?

Hi Oliver,

I'd love to know how the v4.1 letter works. It sounds easier on the surface, but all the comments we have gotten are all about specific metrics. It's not clear to me how you'd have those in the IP meeting at schematic design where you are having these conversations that you would be recording in this letter. It's almost like the letter is some kind of format for the meeting. I see others have commented on using the letter approach. Maybe some one would be so kind as to explain exactly how they structured that and got approval?

I'd love to know how it works too!  Unfortuantely I haven't tried it myself yet, though am soon to submit several v4 applications and am considering switching to this approach due to the removal of the ambiguous two strategy requirement.  I can let you know in a couple of months but it would be great if someone can provide guidance sooner!

Just posting to back up what Michelle said, review comments we have gotten interpret this as 14 parameters. Marcus's reading (especially not getting hung up on a number of models to run, or on parameters that aren't appropriate for the project) makes much more sense to me, but it does not seem to be how reviewers are reading the language. I would not be shocked if reviewers are as unclear on the intent of that langauge as the rest of us.

I don't know if you're likely to succeed getting a LEED interpretation published, but you might ask LEED Coach for a clarification before submitting. I just got this comment back on a precert review (!) and plan to contact them to push back/ask for clarification going forward. 

Just to let you all know, I have received a response from LEED Coach:

"The LEED v4 member-balloted requirements of this credit indicate that the team must "Assess at least two potential strategies associated with each of" the design scenarios listed. So, the team would need to address all 14 strategies in order to demonstrate compliance, unless the team provides a narrative providing a justifiable reason why more than one assessment per strategy could not be completed. That being said, the LEED v4.1 requirements were intentionally written to provide teams with a more balanced approach to this credit, and the LEED v4.1 credit may be used as a credit substitution for any LEED v4 project."

So anyone who doesn't think it is relevant for the project to address 2 strategies in each of the 7 categories would be well advised to go with v4.1 requirements...