[Bldg-sim] Spam:Re: LEED modeling requirements for existingbuildings

[Eric O'Neill]

Good morning all,
 
Mike is correct here. My apologies.

Eric 

 

________________________________

From: Michael Tillou [mailto:michael.tillou at gmail.com] 
Sent: Thursday, August 21, 2008 8:15 AM
To: 'Jay Keazer'
Cc: Eric O'Neill; 'Mark Sorensen'; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] Spam:Re: LEED modeling requirements for
existingbuildings


Jay,
 
It is my understanding that that is the correct interpretation.  
 
However, I don't think Eric's interpretation that the baseline rotation
requirement does not apply to existing buildings is correct. Let me
explain why I disagree.  
 
Requirement f in Part 5 of Table 3.1 refers specifically to the baseline
building design (note the italics which signify that a phrase or word is
defined in Section 3 of the Standard) while Requirement a in Part 5 of
Table 3.1 refers specifically to the baseline building performance
(again in italics).  The baseline building design is not the same as the
baseline building performance and therefore Requirement f. cannot
supercede Requirement a in any case.  
 
One last comment about the equal window distribution.  ASHRAE  90.1-2004
Addendum a removes the equal distribution requirement for windows in the
baseline.  If you're working on a LEED project I suggest you consider
adopting Addendum a to avoid this requirement.  USGBC has allowed the
use of ASHRAE 90.1-2004 addenda.  If you do decide to adopt Addendum a
remember that USGBC requires that you incorporate all the changes
included in the Addenddum.  Addendum a has a total of eight changes to
Appendix G, most important of which are the changes to the calculation
of the baseline HVAC system types.
 
regards,
 
Mike
 
Michael Tillou, PE, LEED
Tillou Engineering, LLC
Williamstown, MA 01267
P: 413-458-9870 C: 413-652-1087

________________________________

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Jay Keazer
Sent: Tuesday, August 19, 2008 10:42 AM
To: Eric O'Neill; Mark Sorensen; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Spam:Re: LEED modeling requirements for
existingbuildings



What about the baseline envelope assemblies?  As an example I have an
existing building where the windows are being replaced and insulation is
being sprayed on the outside of a built up roof.   

 

In the same column of Table G3.1, requirement (b) states that "Opaque
assemblies used for alterations shall conform with 5.1.3" and
requirement (c) states that "The fenestration areas for envelope
alterations shall reflect the limitations on area, U-factor, and SHGC as
described in 5.1.3."

 

5.1.3 states that "Alterations to the building envelope shall comply
with the requirements of Section 5 for insulation, air leakage, and
fenestration applicable to those specific portions of the building that
are being altered."

 

My interpretation is: because the windows and roof are being altered, I
have to use the appropriate U-factors and SHGC from the tables for the
baseline windows and roof.  However, the walls are not being altered, so
I can use the existing construction for the baseline walls.  

 

Does anybody have a different interpretation?

 

Thanks!

 

Jay Keazer,  EI

Energy Engineer

TME, Inc.

2039 N Green Acres Road

Fayetteville, AR  72703

 

ph   479.521.8634

fax  479.521.1014

jkeazer at tmecorp.com <mailto:email at tmecorp.com> 

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

 

 

 

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Eric
O'Neill
Sent: Thursday, August 14, 2008 3:16 PM
To: Mark Sorensen; bldg-sim at lists.onebuilding.org
Subject: Spam:Re: [Bldg-sim] LEED modeling requirements for existing
buildings

 

Mark, 
Under ASHRAE 90.1 Appendix G, Table G3.1, Section 5, "Baseline Building
Performance" column, requirement (f) (take a breath...) it states that
"For existing building envelopes, the baseline building design shall
reflect existing conditions prior to any revisions that are part of the
scope of work being evaluated". So the rotation doesn't apply to you.
Also, I interpret that to mean the windows don't need to be
redistributed either. Hope that helps!

Eric O'Neill 
Mechanical Engineer 
Energy Division - Michaels Engineering 

811 Monitor St. Ste 100 
La Crosse, WI 54603 
v: 608-785-1900 x521 
f: 608-784-2270 
elo at michaelsengineering.com 
http://www.michaelsengineering.com <http://www.michaelsengineering.com>


From: Mark Sorensen [mailto:DEnergyServices at comcast.net
<mailto:DEnergyServices at comcast.net> ]
Sent: Thursday, August 14, 2008 10:40 AM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] LEED modeling requirements for existing buildings

When modeling an existing building, is required to calculate the
proposed building window to wall ratio and equally redistribute the
glass area to the baseline building and prepare models for the four
rotation exposures? My take is that for a proposed existing building,
there is not an opportunity to position the building to the most
advantageous exposure and you could end up being penalized if the
baseline energy use is averaged for all rotations but I have not been
able to find any reference in LEED or ASHRAE to support this. I'm not
sure what to think about equal redistribution of the glass areas. 

Mark Sorensen 
Diversified Energy Services 
5890 E. Pontaluna Rd. 
Fruitport, MI 49415 

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