[BLDG-SIM] LEED Building Orientation

Timothy Moore tcm at berkeley.edu
Mon Dec 3 01:06:32 PST 2007


Jason, Brandon, and others doing building simulation for LEED:

 

Great to see all of the discussion this topic is generating. It seems well
worth considering how better to provide an incentive for orientation without
needless hassles and penalties. If you’re interested in doing so, please
read on and comment.

 

The 90.1-2004 Appendix G requirement for averaging the results of four
baseline building orientations is, as described by previous comments in this
discussion, a somewhat arbitrary and often problematic means of attempting
to give credit (or penalty) for building orientation. It can also be a
time-consuming pain either when overshadowing from adjacent buildings is
modeled (fixed shades), and thus the site shape and coordinate origin may
not make sense for a rotated building, or when attempting to compare
benefits over the baseline model related to specific strategies (i.e.,
baseline+X vs. baseline+Y, acknowledging that relative comparisons of
strategies can and should most often still be made without ever rotating
anything).  

 

Of potentially even greater concern, in some cases, such as on a very narrow
site with N-S major axis, the current requirement needlessly penalizes
(i.e., deducts credit from) a design that may be making the best of a
constrained situation. Thus, even if the process of generating and averaging
baseline performance results for all four orientations were fully automated
in the simulation tools, which would alleviate the time and hassle, the
current approach would still impose an unfair and unhelpful penalty on
certain projects that are forced to orient their building along a N-S axis
or with a large SE, SW, or W exposure, etc. 

 

However, I agree that we do need some method of encouraging and rewarding
beneficial building orientations where applicable. 

 

It appears the draft Addendum R language that was never approved was one
idea for how to address some of the issues described above. I would hazard a
guess that it was not approved because of the tendency for such language of
"exceptions" to become a loophole open to interpretation and gaming, and
thus something likely to weaken the performance rating method and generate
more work for reviewers, not to mention superfluous LEED credit
interpretation rulings. 

 

I support the idea of a positive incentive or opportunity offered by the
option for comparing to the averaged results for the rotated baseline
building, plus a similar option with respect to glazing orientation, if and
when permitted by straightforward criteria. I would propose the following
requirements be met for the optional use of such averaged values for the
baseline building


 

The project would need to show simple documentation that one of the two
options was indeed applicable, and thus they should be permitted to use the
associated method for adjusting the baseline building results: 

 

Option 1) Demonstrate via a simple sketch or other graphic representation
that there is space on the site for the same total building footprint area
to be re-shaped to be either more nearly square in terms of solar
orientation OR to be rotated at least 60 degrees (or similar value TBD) from
the design orientation---thus it would have been possible and plausible to
neglect building orientation. In this case the team would be permitted to
compare to an average of rotated baseline building results as in 90.1-2004
Appendix G. As with Appendix G, overshadowing from adjacent buildings, etc.
would need to be modeled as a fixed shading item that does not rotate with
the building. For cases where the proposed building orientation is elongated
and rotated by something less than 60 degrees (or whatever similar threshold
was established for this option)---for example, rotated 45 degrees from the
orientation of the major axis of the site, adjacent road, adjacent
buildings, etc.---and there is not enough space on the site to rotate it a
full 60 degrees, the team should be permitted (if they see fit) to compare
to a baseline result that is the average of just two orientations of the
very same footprint: the proposed orientation and whatever they believe to
be the worst orientation of the same footprint shape that would actually
still fit on the site. If Option #1 were selected, doing so would eliminate
Option #2 in order to avoid double counting.

 

Option 2) Demonstrate with simple table of summed values that the glazing
fraction or window-to-wall ratio (WWR) for the facades on the proposed
design is asymmetric in terms of orientation (e.g., differences are greater
than 5%), AND confirm that this is NOT an outcome forced by an immediately
adjacent building or other constraint of the physical building site, but
rather a deliberate design strategy---thus the design could have neglected
any such orientation of WWR. In this case the team would be permitted to
compare their design to a baseline with identical WWR for all façade
orientations---i.e., evenly distributed glazing as indicated by WWR (but not
a rotated building, as in Option #1).

 

The idea here is to permit teams to get credit for either building
orientation OR glazing orientation on the building if they believe it to be
significant AND it would have been possible to neglect it. 

 

If neither of these options were applicable and implemented, the baseline
building would simply be modeled in the same orientation as the proposed
design and with the same proportional distribution of WWR, in keeping with
90.1 WWR limits.  

 

I do not believe it is workable to penalize those who neglect orientation,
as the present Appendix G attempts to do, without creating other
inappropriate penalties and deterrents that we all really could do without.
The penalty for those who neglect orientation where there was a significant
potential to benefit from doing otherwise would, in what I have proposed,
simply be the foregone opportunity to do better and get credit for it. Thus
building orientation would be recognized and treated in much the same manner
as most other performance-related architectural design strategies.

  

I'm interested in what others think of these ideas as possible means of
addressing concerns raised in this discussion. Perhaps, Jason, you could
forward this to the 90.1 committee people that are involved specifically
with the Performance Rating Method (along with related or subsequent
comments from others on the BLDG-SIM forum). Hopefully we can move this
forward.

 

Best,

Timothy

 

Timothy Moore,

LEED AP, Design Consultant, Building Performance Simulation

 

Whole Systems Design

910 Indian Rock Ave.

Berkeley, CA 94707

 

Office: 510-525-4809

Mobile: 303-324-1044

eFax: 413-480-7252

 <mailto:tmoore at whole-systems-design.com> tmoore at whole-systems-design.com


 

  _____  

From: BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] On Behalf Of Brandon
Nichols
Sent: Friday, November 30, 2007 11:22 AM
To: BLDG-SIM at gard.com
Cc: Peter.Simmonds at ibece.net; Leonard Sciarra
Subject: [BLDG-SIM] LEED Building Orientation



Thanks Jason,

The 'burr' under my saddle on this issue is that the 'averaged buiilding',
and therefore the baseline to which all project EEMs are to be compared,
does not exist, not even in the simulation software.

While we may have four perfectly good orientations, any one of which could
be used as a baseline (think .SIM file), there simply exists no .SIM file
for the averaged building.  It would need to be created (as of this writing)
manually, and the result could not be used easily, let alone seamlessly, as
the baseline for alternative comparisons within eQuest.

Suggestions:

1. Allow selecting the orientation closest to, without performing worse
than, the 'average total annual energy consumption' as the baseline.  This
simple change would allow all baseline numbers to reside within the analysis
software.

2. Make this requirement optional, for those buildings which can benefit
from orientation optimization.  In other words, promote achievable
incentives instead of enforcing arbitrary punishments.

Wish I had more time to help out with 90.1 -- maybe next year!

Regards

Brandon Nichols, PE, LEED® AP
Mechanical
HARGIS ENGINEERS

600 Stewart Street
Suite 1000
Seattle, WA 98101
www.hargis.biz

d | 206.436.0400  c | 206.228.8707
o | 206.448.3376  f  | 206.448.4450



-----Original Message-----
From: Jason Glazer [mailto:jglazer at gardanalytics.com]
Sent: Friday, November 30, 2007 8:04 AM
To: Peter.Simmonds at ibece.net; Brandon Nichols
Subject: Re: [BLDG-SIM] LEED Building Orientation

Peter and Brandon,

This looks like an issue that you have a strong opinion so perhaps consider
contributing a better solution. Anyone can propose a change to 90.1.
Further, if you examine this history of the ECB subcommittee, I think you
would find that we are open to good ideas and are trying to balance multiple
needs. The building rotation concept replaced a much worse concept of
spreading the windows around the building evenly.
  Maybe you can find a better solution. I believe we need to reward those
that do make an effort to orient their building
  and windows to save energy and penalize those that make poor design
choices about building orientation and window placement.  The building
rotation idea has traction because most of the effort needed for each
rotation is just to rerun the simulation with the building azimuth changed.
We thought that was simple.  It is an issue that has been discussed many
times in the ECB subcommittee and a few times at the full committee level.

I look forward to your suggestions.

Jason



On 11/30/2007 8:34 AM, Peter Simmonds wrote:
> Here here Brandon. A building is a building and that’s that. I have
> sat through many charette’s  on ‘tree hugging’ projects to hear how
> the buildings orientation can affect the cooling and heating load, let
> alone natural daylighting. Only to hear the wise men of 90.1 (who have
> never designed a building) to come up with some ‘weighted’ average to
> change the results. The designer ends up doing four different runs
> only to find out that the architect didn’t have clue what he was
> trying to do in the first place.
>
> 
>
> Long live sanity.
>
> 
>
> Peter Simmonds Ph.D.
>
> Associate
> IBE Consulting Engineers
>
> 14130 Riverside Drive Suite 201
>
> Sherman Oaks, CA 91423
> p:   (818) 377-8220
> f:    (818) 377-8230
> m:  (818) 219-1284
> IDEAS FOR THE BUILT ENVIRONMENT <BLOCKED::http://www.ibece.com/>
>
> This e-mail message, including any attachments, is for the sole use of
> the intended recipient(s) and may contain confidential and privileged
> information. Any unauthorized review, use, disclosure, or distribution
> is prohibited. If you are not the intended recipient, please contact
> the sender by reply e-mail and destroy all copies of the original message.
>
> ----------------------------------------------------------------------
> --
>
> *From:* BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] *On Behalf Of
> *Brandon Nichols
> *Sent:* Thursday, November 29, 2007 5:48 PM
> *To:* BLDG-SIM at gard.com
> *Subject:* [BLDG-SIM] LEED Building Orientation
>
> 
>
> All,
>
> 
>
> The building rotation requirement is utterly nonsensical.  For a
> full-text rant on the subject, see my previous post:
>
> 
>
> http://www.gard.com/ml/bldg-sim-archive/msg04038.html
>
> 
>
> In summary:
>
> 
>
> 1) In the case of many new buildings (90% or more I would estimate),
> there is very little latitude for changing the orientation.
> For example the main street and therefore the lobby and entryway may
> be on one side and one side only of the building, the aspect ratio of
> the building may not fit on the lot in two of the four orientations, etc.
>
> 
>
> 2) The fictitious, etheral 'averaged' building does not exist even in
> the computer code of the best analysis programs we have at our
> disposal to date.
>
> 
>
> 3) All baseline numbers for each of the four orientations would need
> to be extracted from the analysis software, and averaged on a spreadsheet.
> Similarly each and every EEM would need to be extracted, and the
> project's comparative analysis done on a spreadsheet instead of the
> within the analysis software itself.  Thanks, but I have a life, wife
> and family.
>
> 
>
> 4) If this requirement still sounds like a good idea from the comfort
> of your tenured office, I say come on out and run couple of dozen
> real-life energy code and LEED compliance simulations for me within
> budget and on deadline in Q1-Q2 2008 and you'll begin to understand
> what I'm talking about.
>
> 
>
> Why not simply allow selecting the orientation closest to, without
> performing worse than, the 'average' as the baseline?  This simple
> change would allow the baseline numbers to reside within the analysis
> software.
>
> 
>
> Alternatively the eQuest developers are rumored to be working on a
> 90.1 Appendix G compliance module.  Upon release, if it automates the
> averaging I may be inclined retire some portion of this diatribe.
>
> 
>
> Best idea yet, drop this as a requirement, and make it optional where
> it makes sense to do so. Utilize by default the far more intuitive
> (and useful in terms of energy incentives) 'code minimum' baseline
> building, oriented identically to the proposed.  This is the approach
> I've been able to convince our state energy code and utility rebate
> reviewers to accept -- its just hardened LEED extremists who still
> seem to have their head in the sand on this.
>
> 
>
> 
>
> Regards
>
> 
>
> 
>
> Brandon Nichols, PE, LEED^® AP
>
> Mechanical
>
> **HARGIS ENGINEERS**
>
> 600 Stewart Street
>
> Suite 1000
>
> Seattle, WA 98101
>
> www.hargis.biz
>
> 
>
> *d |* 206.436.0400  *c | *206.228.8707
>
> *o |* 206.448.3376  *f  |* 206.448.4450
>
> 
>
> 
>
> 
>
> ----------------------------------------------------------------------
> --
>
> *From:* BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] *On Behalf Of
> *Edward.A.Decker at jci.com
> *Sent:* Thursday, November 29, 2007 3:59 PM
> *To:* BLDG-SIM at gard.com
> *Cc:* BLDG-SIM at gard.com
> *Subject:* [BLDG-SIM] LEED Building Orientation
>
>
> Can you not apply various fenestrations and shading to the model
> without having to change its orientation? For an existing building,
> including LEED EB, what additional benefit could be gained by rotating
> the model since you cannot change the orientation?
> _____________________________________________
> Edward A. Decker
>
>
> *"Leonard Sciarra" <leonard_sciarra at gensler.com>* Sent by:
> BLDG-SIM at gard.com
>
> 11/29/2007 06:18 PM
>
> Please respond to
> leonard_sciarra at gensler.com
>
>      
>
> To
>
>      
>
> <BLDG-SIM at gard.com>
>
> cc
>
>      
>
> 
>
> Subject
>
>      
>
> [BLDG-SIM] LEED Building Orientation
>
> 
>
> 
>
>      
>
> 
>
>
>
>
> This is true, however, even with an existing building, you as the
> designer/engineer have the option of "working" the facades and
> applying appropriate fenestration, shading, etc... you can still make
> good/bad decisions and the fact that your footprint is fixed should
> not give the design team a waiver from the fact that the sun still
> rises in the east and sets in the west.  In fact it may be a benefit
> if perhaps your building is shaded on the west by itself.
> 
> Leonard Sciarra, AIA, LEED ap
> 312.577.6580 (Dir)
> G E N S L E R | Architecture & Design Worldwide 30 West Monroe Street
> Chicago IL, 60603
> 312.456.0123
> leonard_sciarra at gensler.com
>
> 
>
> ----------------------------------------------------------------------
> --
>
> *From:* BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] *On Behalf Of
> *Ross-Bain, Jeff*
> Sent:* Thursday, November 29, 2007 2:40 PM*
> To:* BLDG-SIM at gard.com*
> Cc:* keith_lane at g-g-d.com*
> Subject:* [BLDG-SIM] LEED Building Orientation
>
> Here is my question to and response from the USGBC regarding this issue:
> 
> 
> Dear LEED Info,
> 
> There has been a lot of chat on this item and I wonder if there is a
> USGBC position – I found no reference to this in the CIR’s:
> 
> Do existing buildings undergoing renovation require the four-point
> compass orientation analysis?
> 
> 
> 
> Jeffrey,
> 
> If the existing building being renovated is pursuing LEED-NC rather
> than LEED-EB, then it would indeed be required to undergo the
> specified analysis.  This analysis is used to establish the baseline
> for energy performance using the ASHRAE standard.  LEED doesn’t have
> any specific exemptions for existing buildings in this requirement,
> but if ASHRAE has some kind of exemption, we will honor that.
> 
> 
> So I guess the question then becomes an interpretation of the Appendix
> G (Table G3.1 (f)) comment for existing buildings. Rotate or not?
> 
> My take has always been that new buildings have the option to consider
> orientation but existing buildings cannot be re-oriented so rotating
> the model does not really prove anything.
> 
> Any 90.1 code committee members or others out there have an
interpretation?
> 
> Regards,
>
> */Jeffrey G. Ross-Bain, PE, LEED/*
> Smith Dalia Architects
> 621 North Ave NE
> Suite C-140
> Atlanta, GA, 30308
> 404-892-2443 _
> _www.smithdalia.com <http://www.smithdalia.com/>
>
> P *Consider the environment.* *Please don't print this e-mail unless
> you really need to.*
>
> 
>
> ----------------------------------------------------------------------
> --
>
>
> *From:* BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] *On Behalf Of
> *Neuhauser, Ken*
> Sent:* Thursday, November 29, 2007 2:31 PM*
> To:* BLDG-SIM at gard.com*
> Cc:* keith_lane at g-g-d.com*
> Subject:* [BLDG-SIM] LEED Building Orientation
> 
> I am not the authority, Keith, but I believe that your interpretation
> (that existing buildings do not get rotated in the baseline) is
> consistent with the intent of Appendix G.  In new construction, the
> decisions regarding building orientation will affect performance and
> that performance should be measured against the baseline (although,
> there are cases, such as a building that adjoins buildings to either
> side, where rotating the baseline through all four orientations does
> not make sense).  If you’re improving an existing building, the
> existing conditions of building enclosure components, including
> orientation, are an appropriate baseline.  When we apply Appendix G to
> existing buildings, we have also found that “existing building envelopes”
> sometimes needs to be parsed into existing building envelope components.
>  For example, in a mill rehab, the bearing walls may be serviceable
> and appropriately modeled “as is” in the baseline, but missing windows
> or windows that are clearly not serviceable we model as per the ASHRAE
> minimum compliance.
> 
> You should note, also, that an addendum to the standard has removed
> the provision in the table under G3.1, 5c to distribute windows
> uniformly in horizontal bands across the four orientations.  That
> should make all of our lives easier.
> 
> Regards,
> Ken Neuhauser, M.Arch, MSc.Arch, LEED AP /Architectural Project
> Manager/ Conservation Services Group, Inc.
> 40 Washington Street
> Westborough, MA 01581
> Ph. 508 836-9500 ext. 13226
> Fax 508 836-3181
> www.csgrp.com <http://www.csgrp.com/>
> 
> 
> 
>
> 
>
> ----------------------------------------------------------------------
> --
>
>
> *From:* BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] *On Behalf Of
> *Keith Lane*
> Sent:* Tuesday, November 27, 2007 2:40 PM*
> To:* BLDG-SIM at gard.com*
> Subject:* [BLDG-SIM] LEED Building Orientation
> 
> I am modeling an existing building for Energy & Atmosphere Credit 1:
> Optimize Energy Performance. In LEED and table G3.1 No. 5(a) of ASHREA
> Standard 90.1-2004, it states that “the baseline building performance
> shall be generated by simulating the building with its actual
> orientation and again after rotating the entire building 90, 180, 270
> degrees, then averaging the results”. However table G3.1 No. 5(f) of
> ASHREA Standard 90.1-2004 states: “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.”
> Would this mean that you do not need to simulate the building for the
> four orientations? It just doesn’t seem to make sense to simulate the
> building in such a manner if it is existing. I am new energy modeling
> for LEED credit and sincerely appreciate any assistance.
> 
> Thank you,
> 
> */Keith Lane, LEED AP/*
> */Mechanical Engineer/*
> Garcia.Galuska.DeSousa
> /Consulting Engineers                     Inc.                        /
> 370 Faunce Corner Road, Dartmouth, MA 02747
> p.508.998.5700                          f. 508.998.0883
> 
> 
> 
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