[Bldg-sim] Modeling 90.1 Baseline Envelope for Existing + Additions

[Santiago Velez]

David, exactly, that is another way to go. Even if I decide to maintain 40%
and 5% thresholds, there are some different ways of getting there,
considering the mixed existing + addition issue. This is why I agree
requesting some feedback is the way to go.
The existing warehouse was included because is part of the LEED scope and
because it doesn't meet *Table G3.1.2  Additions and alteration to exclude
existing building  "c. Design space temperature and HVAC system operating
setpoints and schedules on either side of the boundary between included and
excluded parts of the building are essentially the same."*

Some renovation is happening in the existing bit, lightings is fully
replaced to LED and roof insulation is added. Shading for skylights was
suggested and opted out by the client for various reasons during design. In
the project's weather, 3A, insulations is not as big of an issue as solar
radiation control. So worst case scenario, shading those skylights might be
simple solution to be close to the savings the project was aiming. On the
other hand It is never nice to tell a client you have to add something to
the project once construction has finished, so its worth defending our
approach and our clients interests with reviewers.

Santiago.


2013/11/5 David Eldridge <DEldridge at grummanbutkus.com>

>  The baseline guidelines might both still apply though, let me throw this
> interpretation out there. Either way, you should ask for clarification on
> your proposed path before submitting if possible.
>
>
>
> 1.       Model the existing as-is per the reference that you noted. Seems
> straightforward.
>
>  2.       Whole-building totals might still be required to match the 40%
> and 5%, *unless superseded by #1. This seems to be the point of
> discussion with the reviewer*.
>
>
>
> In that case the baseline total glazing for the existing portion would be
> modeled as existing. The new construction baseline would have any remainder
> of glazing area up to 40%. It sounded like you would be below 40% total, so
> model as you did before with the basline = proposed.
>
>
>
> For skylights the existing building “consumes” more than 5% of the whole
> project, therefore the skylight area would be capped at whatever the actual
> percentage is based on the existing. The baseline would not have skylights
> in the new construction unless they were required to be added by some other
> part of the code or local requirements in order to meeet the 5%
> requirement. This could benefit you if the project is adding photocell
> control of the lighting in the new addition in conjunction with the
> skylights.
>
>
>
> G1.3 is tricky since there is also a new portion to the project that can
> still impact the overall percentages, even if the existing portion is
> modeled as-is. And none of the complex is excluded from the renovation,
> although the envelope may not be changing. Assuming that lighting, HVAC,
> and interiors are being renovated in the existing warehouse? Otherwise your
> LEED project boundary should only be the new addition.
>
>
>
> David
>
>
>
>
>
>
>
>
> David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP
>
> *Grumman/Butkus Associates*
>
>
>
>
>
>
>
>
> *From:* bldg-sim-bounces at lists.onebuilding.org [mailto:
> bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Santiago Velez
> *Sent:* Tuesday, November 05, 2013 11:27 AM
> *To:* Maria Karpman
> *Cc:* bldg-sim at lists.onebuilding.org
> *Subject:* Re: [Bldg-sim] Modelling 90.1 Baseline Envelope for Existing +
> Additions
>
>
>
> Maria thanks for sharing your opinion. I will reach out to the reviewer.
>  It's good to know there can be different interpretation. I do understand
> that if you are certifying as "New construction and Mayor renovations" it
> might make sense that you need demonstrating savings against the full new
> Baseline defined by Appendix G.  It would be nice if future editions of the
> standard were more clear about this and other issues that seem to fall in
> grey areas.
>
>
>
> Thanks.
>
> Santiago.
>
>
>
> 2013/11/5 Maria Karpman <maria.karpman at karpmanconsulting.net>
>
> Santiago,
>
>
>
> I would reach out to the reviewer and argue that your original
> interpretation is correct. Appendix G Table 3.1.5 f that you quoted below
> clearly suggests that the baseline building design for renovation projects
> shall reflect existing conditions prior to any revisions. The section
> covers all aspects of envelope including thermal and solar properties,
> assembly type, and surface area, so there is no indication that the
> “existing conditions” mentioned in 3.1.5 f exclude fenestration / skylight
> area. I don’t see why this rule should be void for projects that include
> both renovation and addition. Section G1.3 is also relevant: *G1.3
> Trade-Off Limits. *When the proposed modifications apply to less than the
> whole building, *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*. Since the window/skylight area is not modified, it
> should produce neither penalty nor credit for the proposed design.
>
>
>
> Maria
>
>
>
> *From:* bldg-sim-bounces at lists.onebuilding.org [mailto:
> bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Santiago Velez
> *Sent:* Monday, November 04, 2013 7:16 PM
> *To:* Nick Caton
> *Cc:* bldg-sim at lists.onebuilding.org
> *Subject:* Re: [Bldg-sim] Modelling 90.1 Baseline Envelope for Existing +
> Additions
>
>
>
> PS. : My interpretation was mostly based on *Appendix G Table 3.1.5 f)
> "Existing Buildings. 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."*
>
>
>
>
>
>
>
> 2013/11/4 Santiago Velez <santiagogvelez at gmail.com>
>
> Nick, thanks for the response. The answer is yes, I'am trying to make a
> case for exceeding the 5% threshold for existing bit of the project, which
> is not modified.
>
> The project is a big existing conditioned warehouse, with lots of
> skylights (18% of roof area), the new bit is an office building, with more
> skylights (properly shaded this time!). I thought it would be fare to have
> a baseline which maintains the existing bit exactly the same (18%
> skylights), and the new addition according to Table G3.1.5 (5%). The global
> skylight area for the whole project is *12%*, and this was reviewed.
>
> The opposite happens for vertical fenestration, warehouse has almost no
> windows, and the new office is fully glazed. With the same criteria,
> existing stays the same, new is 40% max; then the proposed ends up with
> global 32% WWR and baseline only 28%. This was reviewed as well.  Am
> I explaining my self?
>
>
>
> I thought this would be fair, and in fact it made so much sense I thought
> it was the only possible interpretation... Its very good to remember one an
> be *very* wrong.
>
>
>
> So my approach should be:
>
> - For vertical fenestration, 32% both baseline and proposed.
>
> - For the skylights, I would multiple every skylight by  5/12 to get a
> global 5% skylight.
>
>
>
>  Hmmm....energy savings are going to plummet.
>
> Thank you again Nick.
>
>
>
> Santiago.
>
>
>
> 2013/11/4 Nick Caton <ncaton at smithboucher.com>
>
> Proposed and Baseline areas/layouts matching works perfectly until you
> exceed either 40% for vertical or 5% for skylights.  See Table G3.1.5,
> baseline items c. and d.  This might be coincidence, but just to be cover
> all bases: 28% + 12% = 40% is an incorrect reading – the skylight and
> vertical fenestration thresholds are independent.
>
>
>
> I think you are to leave the vertical fenestrations alone (being under the
> 40% threshold) and you need to proportionally lower the area of the
> skylights in the baseline model to get back to 5%.  Proposed model needs to
> match actual design so it’s skylights remain the same.
>
>
>
> I’m not certain how or if the project being a major renovation has any
> bearing on the matter.
>
>
>
> Are you making the case that the existing skylights are envelope
> components not being touched, and so should remain equal in area between
> the models despite exceeding the 5% threshold?  Do you have additional new
> skylights complicating the matter?
>
>
>
> ~Nick
>
>
>
>
>
> *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
>
>
>
> *From:* bldg-sim-bounces at lists.onebuilding.org [mailto:
> bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Santiago Velez
> *Sent:* Monday, November 04, 2013 3:20 PM
> *To:* bldg-sim at lists.onebuilding.org
> *Subject:* [Bldg-sim] Modelling 90.1 Baseline Envelope for Existing +
> Additions
>
>
>  Dear forum users, I have modelled a project following Appendix G. and
> have received a review regarding my interpretation of % glazed area on the
> baseline.
>
> The project is a mayor renovations + Additions (existing conditioned
> warehouse + New office building attached). There were no modification on %
> area of vertical and horizontal glazing on the existing bit of the building.
>
> My approach was to model existing envelope, shape and fenestration,
> exactly the same in both proposed and baseline. The addition was modelled
> following the "maximum 40% for vertical fenestration and 5% for skylight"
> rule. The result of the whole building for baseline is, 28% vertically
> glazed and 12% of skylights (the existing bit was very different than 40%,
> and 5% respectively)
> The reviewer states that the end result for the baseline should still be
> 40% and 5%. It is not very clear to me how would I get there.. Do I have to
> make the existing fenestration proportionally smaller, just like I would do
> for the baseline of a completely new building?
>
> Thanks in advance.
>
> Santiago.
>
>
>
>
>
>
>
>
>
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