[Bldg-sim] LEED and existing envelopes

[Paul Riemer]

I also agree with the reviewer.  The existing envelope condition stipulation is a double edged sword.   Do you truly think it is a net penalty on your LEED application to add windows?  Other LEED points reward daylight and views, and the thermal energy impacts of the windows are hopefully offset by electric lighting savings.

Paul Riemer, PE, LEED AP BD+C
DUNHAM

From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of James Hansen
Sent: Tuesday, October 11, 2011 1:31 PM
To: Anne Juran; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] LEED and existing envelopes

Thanks for the responses Anne and Bill.  But this seems ridiculous, and goes against everything I've done to date.

So if we have an existing building with no windows, and we want to reuse the building structure/skin (which LEED strongly encourages), we get penalized for wanting some daylight in the building?

I think all of the references to the "baseline building envelope shall represent existing conditions" is intended to demonstrate that you can use existing window and wall coefficients, NOT that you can't add windows.  But what do I know...

Does anyone know for sure?

GHT Limited
James Hansen, P.E., LEED AP
Senior Associate
1010 N. Glebe Road, Suite 200
Arlington, VA  22201-4749
703-243-1200 (office)
703-338-5754 (cell)
703-276-1376 (fax)
www.ghtltd.com<http://www.ghtltd.com/>

From: Anne Juran [mailto:juran at summerconsultants.com]
Sent: Tuesday, October 11, 2011 2:02 PM
To: James Hansen; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] LEED and existing envelopes

I find existing envelopes always tricky because the information is not delivered in the clearest manner.  However, I think in this case the reviewer is correct, based on 90.1 Table G3.1.5 item f under "Baseline Building Performance" and page G-17 of the User's Manual.  Also, in item c they explicitly state that it applies to new buildings and additions, but do not list existing (other than the little blip about alterations and 5.1.3.)


From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of James Hansen
Sent: Tuesday, October 11, 2011 10:23 AM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] LEED and existing envelopes

I know this has been covered before, but I just received the following comment from a GBCI reviewer for a v3 Core and Shell project I'm working on.  The project is basically an existing 5-story warehouse with almost no windows.  Part of the renovation is adding windows.  The comment is as follows:

Table 1.4.1B indicates that the window-to-gross-wall ratio is identical in both cases; however it is unclear whether any fenestration was added or removed as part of the renovation. The baseline ratio must reflect the ratio as it existed prior to the renovation and the proposed ratio must reflect the ratio as it exists after the renovation. Revise the Baseline and/or Proposed cases as necessary so that the window-to-gross-wall ratio is accurately modeled and provide a revised prerequisite form and updated energy model output summaries as necessary.

I didn't think that this was the case - I thought that if you had an existing building, any EXISTING-TO-REMAIN windows would show up as the existing window type, but any NEW windows in the proposed alteration would be matched in the baseline model and comply with the Table 5.5 requirements.  Meaning the WWR remained the 1:1 as long as it was < 40% glass.

I think this is just a matter of educating the reviewer on our building, but I wanted to make sure that there hadn't been a shift in how GBCI reviews existing buildings.

Thanks!

GHT Limited
James Hansen, P.E., LEED AP
Senior Associate
1010 N. Glebe Road, Suite 200
Arlington, VA  22201-4749
703-243-1200 (office)
703-338-5754 (cell)
703-276-1376 (fax)
www.ghtltd.com<http://www.ghtltd.com/>

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The information contained in this communication is confidential, may be privileged, and is intended only for the use of the addressee.  It is the property of GHT Limited.  Unauthorized use, disclosure or copying of this communication or any part thereof is strictly prohibited and may be unlawful.  If you have received this communication in error, please notify me immediately by return e-mail or by e-mail to ght at ghtltd.com<mailto:ght at ghtltd.com>, and destroy this communication and all copies thereof, including all attachments.  Thank you.
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The information contained in this communication is confidential, may be privileged, and is intended only for the use of the addressee.  It is the property of GHT Limited.  Unauthorized use, disclosure or copying of this communication or any part thereof is strictly prohibited and may be unlawful.  If you have received this communication in error, please notify me immediately by return e-mail or by e-mail to ght at ghtltd.com<mailto:ght at ghtltd.com>, and destroy this communication and all copies thereof, including all attachments.  Thank you.
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