[Equest-users] existing buildings/alterations

[David Eldridge]

I’ll add that of the few times this has come up for me, the result was that since HVAC systems weren’t being modified and envelope also wasn’t modified (and in a few cases neither was lighting being changed) – in which case the project goes into LEED CI instead of LEED NC. Then a model may not have been required.

I’m not sure of the reference, but to be included as a major renovation in LEED generally two of the three would have to be modified among envelope, lighting, and HVAC. Otherwise it makes a great match for commercial interiors depending on the ownership of the building, percent owner-occupied, etc.

But the point being, many projects that have this dilemma about existing HVAC also end up not needing a model at all, so it’s a bit of a self-selecting process that it doesn’t come up as often.

Maybe you are suggesting that there might be some cases to model existing systems as-is where they are in a separate part of the facility but providing service to the project as an addition. But anything inside the project boundary would be Appendix G baseline for lighting or HVAC. Practically speaking this would be mainly applied to tapping off of existing AHUs, since service from existing chilled water or heating systems would fall into district energy guidance if this was a LEED project.

David



David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP
Grumman/Butkus Associates



From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Bishop, Bill
Sent: Thursday, July 25, 2013 4:14 PM
To: Daniel Knapp; Kent Beason
Cc: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] existing buildings/alterations


Dan,



You bring up a section of Appendix G that I have never seen discussed on Equest-users or Bldg-Sim. The 90.1 User's Manual seems to explain G1.3 in terms of including or excluding a portion of the building from the Appendix G analysis. You could choose not to model the existing portion of a building if you are doing an addition, if certain conditions are met. It is not clear to me whether or not this allows existing systems to be modeled for the baseline if they are not replaced as part of a gut rehabilitation. Either way, we agree that you model Appendix G systems in the Baseline if there are new systems in the proposed design.



Regards,

Bill





-----Original Message-----

From: Daniel Knapp [mailto:danielk at arborus.ca]

Sent: Thursday, July 25, 2013 4:34 PM

To: Bishop, Bill

Cc: Kent Beason; 'Nick Caton'; equest-users at lists.onebuilding.org

Subject: Re: [Equest-users] existing buildings/alterations



I guess to follow up the interpretation is as such:



If the existing systems are left in place, the proposed and baseline are modelled identically according to the existing systems.



If the existing systems are *replaced*, the proposed is modelled according to the replacements, and the baseline is modelled according to the 90.1 Appendix G requirements.



Best,

Dan



-----Original Message-----
From: Daniel Knapp [mailto:danielk at arborus.ca]
Sent: Thursday, July 25, 2013 4:31 PM
To: Kent Beason
Cc: Bishop, Bill; 'Nick Caton'; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] existing buildings/alterations



What about G1.3 where it states that



"only parameters related to the systems to be modified shall be allowed to vary.  Parameters relating to unmodified existing conditions or to future building components shall be identical for determining both the baseline building performance and the proposed building performance."



Doesn't this apply to HVAC as well as the envelope?

—

Daniel Knapp, PhD, P Phys, LEED® AP O+M

danielk at arborus.ca<mailto:danielk at arborus.ca>



Arborus Consulting

Energy Strategies for the Built Environment www.arborus.ca<http://www.arborus.ca>

76 Chamberlain Avenue

Ottawa, ON, K1S 1V9

Phone: (613) 234-7178 ext. 113

Fax: (613) 234-0740









On 2013-07-25, at 4:03 PM, Kent Beason <kbeason at estesmcclure.com<mailto:kbeason at estesmcclure.com>> wrote:



> Bill,

>

> Okay...I would classify this as one of those nuances that Nick characterized earlier.  It seems strange to me that this would only apply to the envelope, but after all, it isonly stipulated in Table G3.1 under Section 5f Building Envelope.

>

> To complicate the issue though, someone else's response was to use existing HVAC systems.  Normally I would dismiss his response out of hand, but he was a LEED reviewer at one time and is more 90.1 knowledgeable than me currently.  I was about to send this message, sure that I would model baseline per Appendix G, until I thought to look in Section 6.  Does Section 6.1.1.2 provide the adequate Exception to clarify that old HVAC systems must be modeled in the baseline for a renovation/alteration project?  The term "alteration" in the definitions appears to be applicable as an "addition" as shown in this Exception of 6.1.1.2.  However, the verbiage "shall not be required to comply with this standard" implies that it's optional.

>

> Kent Beason

> -------------------------

> office - 903 581 2291

> cell - 830 609 8904

>

> From: Bishop, Bill [mailto:bbishop at pathfinder-ea.com]

> Sent: Thursday, July 25, 2013 1:55 PM

> To: Kent Beason; 'Nick Caton'; equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>

> Subject: RE: [Equest-users] existing buildings/alterations

>

> Kent,

>

> I didn’t notice your message was only to me. I assumed it would be a matter of seconds before others replied in the negative. The “existing conditions” caveat applies only to the envelope. You must use the Appendix G baseline systems and plants for the LEED Baseline, with the possible exception of the central plant for DES systems as you mention.

>

> ~Bill

>

> From: Kent Beason [mailto:kbeason at estesmcclure.com]

> Sent: Thursday, July 25, 2013 2:49 PM

> To: 'Nick Caton'; Bishop, Bill; equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>

> Subject: RE: [Equest-users] existing buildings/alterations

>

> Thanks for the feedback.    As I asked Bill offline, and I feel it goes without saying, but never hurts to be thorough :-): this applies to the old HVAC systems too, correct?  Obtaining the old HVAC system info could be a daunting challenge unfortunately.

>

> I've learned alot about nuances...  One area of this building is storefront (essentially 100%) single pane glass around the whole perimeter!

>

> Kent Beason

> -------------------------

> office - 903 581 2291

> cell - 830 609 8904

>

> From: Nick Caton [mailto:ncaton at smithboucher.com]

> Sent: Thursday, July 25, 2013 1:32 PM

> To: Bishop, Bill; Kent Beason; equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>

> Subject: RE: [Equest-users] existing buildings/alterations

>

> Agreed.  Take note there are a couple nuances between what’s written in 90.1 and what’s required by the LEED reviewership.  I believe they draw a line in the sand where if more than 50% of a project is “retrofit” vs. NC by square footage, then rotations go away.

>

> I just had 3 LEED projects wrap up at silver/gold where in the initial submission I used thoroughly documented prescriptive baseline envelopes and 4 rotations.  The preliminary review commentary required changing the envelopes to remove the rotations and match reality instead.  The previous reality was (mostly) uninsulated grout filled block walls, single pane windows without film treatments, and zero wall insulation =D!

>

> As a net result, each of these projects jumped way up in unanticipated modeling credits.  It was a good day.

>

> Outside the constraints of LEED, the closer your baseline models can reflect existing realities, the better and more informative the results of your models become for a retrofit analysis.

>

> Regards,

>

> ~Nick

>

> <image001.jpg>

>

> NICK CATON, P.E.

> SENIOR ENGINEER

>

> Smith & Boucher Engineers

> 25501 west valley parkway, suite 200

> olathe, ks 66061

> direct 913.344.0036

> fax 913.345.0617

> www.smithboucher.com<http://www.smithboucher.com>

>

> From: equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org>

> [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of

> Bishop, Bill

> Sent: Thursday, July 25, 2013 1:17 PM

> To: Kent Beason; equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>

> Subject: Re: [Equest-users] existing buildings/alterations

>

> Kent,

>

> Yes, for existing buildings, use the wall & roof assemblies, glazing properties etc. of the existing building for the Baseline values. Also, you don’t have to simulate in four orientations.

>

> Regards,

> Bill

>

> William Bishop, PE, BEMP, BEAP, LEED AP | Pathfinder Engineers &

> Architects LLP Senior Energy Engineer

>

> 134 South Fitzhugh Street                 Rochester, NY 14608

> T: (585) 325-6004 Ext. 114            F: (585) 325-6005

> bbishop at pathfinder-ea.com<mailto:bbishop at pathfinder-ea.com>           www.pathfinder-ea.com<http://www.pathfinder-ea.com>

> P   Sustainability – the forest AND the trees. P

>

> From: equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org>

> [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Kent

> Beason

> Sent: Thursday, July 25, 2013 1:09 PM

> To: equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>

> Subject: [Equest-users] existing buildings/alterations

>

> This question isn't eQuest specific, but deals with 90.1 interpretation.

>

> For an existing building, with regards to shell alterations, G3.1.5-f says that "the baseline building shall reflect existing conditions prior to any revisions that are part of the scope of work being evaluated."  Is this statement as far-reaching as I believe, indicating that U-values, SHGC etc, listed in Tables 5.5 and Appendix A are ignored in a similar way as done in the proposed, since the "baseline" in this case is a real design, rather than a hypothetical baseline?

>

> Kent Beason

> Estes, McClure & Associates, Inc.

> 3608 West Way

> Tyler, TX 75703

> -------------------------

> office - 903 581 2721

> cell - 830 609 8904

>

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