[BLDG-SIM] WWR definition

[Gerald Pde]

Michael,
Appendix-g states that use 40% glazing if glazing % is
above 40%, otherwise use whatever is smaller. From all
the discussions regarding this above-grade/below-grade
issue, we now learn that, as an update to the code,
below grade walls(if the adjecent space is
conditioned) are now included in the WWR calculations.
Appendix-g should not change anything apart from the
fact that glazing will need to be equally distributed
through-out the above-grade facade, am I correct?


Gerald

--- Michael Rosenberg <Michael.Rosenberg at state.or.us>
wrote:

> Since many of you readers are using Appendix G of
> Standard 90.1 for modeling LEED rated buildings you
> should be aware that Table G.3.1.5 states in the
> description of the baseline building for WWR;
> 
>  " Vertical fenestration areas for new buildings and
> additions shall equal that in the proposed design or
> 40% of gross above grade wall area, whichever is
> smaller, and shall be distributed uniformly in
> horizontal bands across the four orientations."
> 
> As for the last part of that requirement,
> distributing fenestration uniformly in horizontal
> bands across the four orientations, that has been
> removed in Addendum A to the 2004 Standard, but will
> not be updated in the published version until 2007. 
> 
> Mike
> 
> 
> 
> Michael Rosenberg
> Oregon Department of Energy
> 625 Marion St. N.E.
> Salem, OR 97301-3742
> Phone : (503) 373-7809
> Fax: (503) 373-7806
> 
> >>> "Larry Degelman" <ldegelman at cox.net> 04/24/06
> 05:07PM >>>
> Possibly the interpretation of what is gross wall
> area depends on what
> version of 90.1 you are looking at.  As for
> 90.1-2004, the official
> interpretation on the ASHRAE web site leaves no
> doubt that "gross wall area"
> include both above- and below-ground walls.  See the
> following item verbatim
> from the ASHRAE web site.
> 
>  
> 
> INTERPRETATION IC 90.1-2004-1 OF ANSI/ASHRAE/IESNA
> STANDARD 90.1-2004
> 
> Energy Standard for Buildings Except Low-Rise
> Residential Buildings
> 
>  
> 
>  
> 
> Date Approved June 25, 2005
> 
>  
> 
> Request from: Roger Chang (E-mail:
> roger.chang at arup.com), Associate Member,
> 155 Avenue of the Americas, New York, NY 10013.
> 
>  
> 
> Reference:  This request for interpretation refers
> to the requirements
> presented in ANSI/ASHRAE/IESNA Standard 90.1-2004,
> Section 5.2.1 Compliance,
> relating to gross wall area.
> 
>  
> 
> Background: Standard 90.1-2004 does not appear to be
> clear as to what gross
> wall area means. International Energy Conservation
> Code is clear that
> prescriptive requirements are based on window to
> above-grade wall area. This
> impacts all sections of the code where the
> window-to- wall area ratio is
> taken into consideration.
> 
>  
> 
>  
> 
> Interpretation: Gross wall area refers to
> above-grade wall only.
> 
>  
> 
>  
> 
> Question:  Is this interpretation correct?
> 
>  
> 
>  
> 
> Answer:  No.
> 
>  
> 
>  
> 
> Comments:
> 
>  
> 
> Section 3.2 defines "building envelope" to include
> "the elements of a
> building*that enclose...spaces through which thermal
> energy may be
> transferred to or from the exterior".
> 
>  
> 
> Section 3.2, in the definition of "wall" states
> "this includes above- and
> below-grade walls, between floor spandrels,
> peripheral edges of floors, and
> foundation walls".
> 
>  
> 
> Section 3.2 defines "gross wall area" as "the area
> of the wall measured on
> the exterior face from the top of the floor to the
> bottom of the roof".
> 
>  
> 
> Therefore, for buildings with conditioned space
> below-grade, the gross wall
> area extends from the top of the surface of the
> floor of the lowest
> conditioned space to the bottom of the roof of the
> highest conditioned
> space.
> 
>  
> 
> (Note that the use of a similar term in a document
> from another organization
> is irrelevant to an interpretation of Standard
> 90.1.)
> 
>  
> 
> Page 1 of 1
> �2005 ASHRAE. All Rights reserved.
> 
>  
> 
>  
> 
> ===================================== 
> 
> Larry O. Degelman, P.E.                 
> ldegelman at cox.net 
> 
> Prof. Emeritus of Architecture    Ph./Fax:
> 1-979-696-2506
> 
> Texas A&M University
> 
> =====================================
> 
>  
> 
> -----Original Message-----
> From: BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com]
> On Behalf Of Jon McHugh
> Sent: Sunday, April 23, 2006 8:40 PM
> To: BLDG-SIM at gard.com 
> Subject: [BLDG-SIM] WWR definition
> 
>  
> 
> Rene, Larry and Gerald,
> 
>  
> 
> I think that the the underground wall area should be
> included for each floor
> that has windows.  These windows in partially below
> ground stories are
> providing light and views that are no less important
> than similar functions
> provided on upper floors.  However, if I have a
> skyscraper with 4 stories of
> underground garage of basement areas, I don't think
> these fully underground
> wall areas should be included.  Rene, in evaluating
> the energy and cost
> impacts of windows in buildings, it is important to
> look at the potential
> for daylighting or the value of view, otherwise an
> engineering analysis
> might conclude that we don't need any windows at
> all.
> 
>  
> 
> Perhaps this should be brought up with the 90.1
> envelope committee.
> 
>  
> 
> Sincerely,
> 
>  
> 
> Jon McHugh, PE, LC
> Technical Director
> Heschong Mahone Group Inc.
> 11626 Fair Oaks Blvd #302
> Fair Oaks, CA 95628 (Sacramento)
> (916)962-7001 ext 38
> (916)962-0101 FAX
> e-mail: mchugh at h-m-g.com 
> URL: www.h-m-g.com 
> 
>  
> 
>   _____  
> 
> From: BLDG-SIM at GARD.COM [mailto:BLDG-SIM at GARD.COM]
> On Behalf Of Renee J.
> Azerbegi
> Sent: Sunday, April 23, 2006 11:11 AM
> To: BLDG-SIM at GARD.COM 
> Subject: [BLDG-SIM] WWR definition
> 
> It depends on the code in use. 
> 
>  
> 
> I submitted an official request (CM proposal) to the
> ASHRAE 90.1 Envelope
> committee to change the definition to only include
> the above grade walls but
> they declined it so it is still the above and below
> grade walls. The reason
> I sent the request is that architects tend to add
> more glazing to the above
> grade walls because they can include the below grade
> walls in the
> definition. I showed some modeling results of the
> difference between a two
> story building with one above and below grade wall
> in a few difference
> cities in the US and there was a significant energy
> impact.
> 
>  
> 
> However, I believe the IECC includes only the above
> grade walls. 
> 
>  
> 
> Ren�e
> 
>  
> 
>  
> 
> Ren�e Azerbegi, CEM, LEED-AP
> 
> President/Sustainable Design Engineer
> 
> ambient energy * solar & sustainable design
> solutions
> 
> t 303.278.1532 | f 303.278.8533 | c 303.885.2695
> 
> renee at ambient-e.com 
> 
> ambient-e.com
> 
>   _____  
> 
> From: BLDG-SIM at GARD.COM [mailto:BLDG-SIM at GARD.COM]
> On Behalf Of Larry
> Degelman
> Sent: Sunday, April 23, 2006 10:26 AM
> To: BLDG-SIM at GARD.COM 
> Subject: [BLDG-SIM] 
> 
>  
> 
> Gerald et al,
> 
>  
> 
> The conventional definition of window-wall-ratio is
> the window area divided
> by the "gross" wall area, though the term
> "window-wall-ratio" is no longer
> among the Definitions section of 90.1-2004.  For
> that matter, WWR is not
> defined in the Abbreviations section.
> 
>  
> 
> Notwithstanding all that, the definition for "Gross
> Wall Area" is clearly
> defined in the 90.1-2004 User's Manual.
> 
>  
> 
> On page 5-30, example 5-G addresses "Determining
> Gross Wall Area", stating
> that this is very significant since the window area
> requirements are based
> on Window-Wall-Ratio (WWR).  
> 
>  
> 
> Answer (as shown on the same page):  "The gross wall
> area includes both
> above-grade walls and below-grade walls so that
> gross wall area is simply
> the perimeter of the building * times the height*"
> 
>  
> 
> Larry D.
> 
> ===================================== 
> 
> Larry O. Degelman, P.E.                 
> ldegelman at cox.net 
> 
> Prof. Emeritus of Architecture    Ph./Fax:
> 1-979-696-2506
> 
> Texas A&M University
> 
> =====================================
> 
>  
> 
> -----Original Message-----
> 
> From: BLDG-SIM at gard.com 
> 
> To: BLDG-SIM at gard.com 
> 
> Sent: Fri Apr 21 09:06:56 2006
> 
> Subject: [BLDG-SIM] ASHRAE 90.1 window-wall ratio
> 
>  
> 
> I recently came across a paper from "Building Energy
> 
> Codes Program" called "Setting the Standard" and
> lists
> 
> out various new code updates. It seems that
> currently
> 
> we are allowed to count below-grade walls as part of
> 
> the window-wall ratio calculations.  Does anyone
> have
> 
> an update on this or point me to the right resource
> to
> 
> confirm this information?
> 
>  
> 
> Thanks.
> 
> Gerald
> 
>  
> 
> __________________________________________________
> 
> Do You Yahoo!?
> 
> Tired of spam?  Yahoo! Mail has the best spam
> protection around 
> 
> http://mail.yahoo.com <http://mail.yahoo.com/>  
> 
>  
> 
>
======================================================
> 
>  
> 
> 
> 
>
=====================================================You
> received this e-mail because you are subscribed
> to the BLDG-SIM at GARD.COM mailing list.  To
> unsubscribe
> from this mailing list send a blank message to
> BLDG-SIM-UNSUBSCRIBE at GARD.COM
> 
>
=====================================================You
> received this e-mail because you are subscribed
> to the BLDG-SIM at GARD.COM mailing list.  To
> unsubscribe
> from this mailing list send a blank message to
> BLDG-SIM-UNSUBSCRIBE at GARD.COM
> 
> 


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

======================================================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM