Dear all,
We intend to certify and existing office building, which is going to be retrofitted with the following criteria:
-No intervention in the envelope
-Partial replacement of the HVAC (both production and distribution systems) and lighting/electrical.
In principle, the envelope ASHRAE mandatory requirements should only be met by the modified elements.
Does the same principle apply for the HVAC and lighting installations?
Or should they be totally renewed in order to fulfill the ASHRAE mandatory requirements?
thanks in advance
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5911 thumbs up
March 31, 2017 - 11:53 am
I agree that you only need to meet the mandatory provisions relative to the items you change. Any unchanged system components are modeled identically.
Alex Parella
Architect_LEED AP11 thumbs up
April 1, 2017 - 12:16 pm
Thanks Marcus,
Another question arises from your answer:
The modeling procedure for the Envelope of Existing buildings in the Baseline is totally explicit in Apendix G:
"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."
Do the systems follow the same logic? That means, modeling the "baseline" systems according the current state.
Or should they be settled following "TABLE G3.1.1A Baseline HVAC System Types"?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5911 thumbs up
April 1, 2017 - 8:10 pm
No. Unchanged lighting and HVAC is modeled identically. If you change it then the baseline is Appendix G.
Alex Parella
Architect_LEED AP11 thumbs up
April 3, 2017 - 6:54 am
Thanks Marcus
Last question:
The current HVAC system is going to maintain its typology, but almost all the units will be replaced by more efficient ones (VRV and generation). The pipelines won't be replaced.
We interpretate that:
-All these replaced units have to fulfill the ASHRAE requirements.
-We can simulate our current HVAC system typology in both, the "baseline" and the "proposed", only changing the efficency and specific parameters (required by ASHRAE) of the replaced units.
(instead of using the generic reference system for the "baseline" defined in the Appendix G)
Is that right?
Francesco Passerini
R2M Solution Srl16 thumbs up
August 2, 2017 - 10:08 am
Hello, Marcus
Is the following interpretation: "I agree that you only need to meet the mandatory provisions relative to the items you change. Any unchanged system components are modeled identically." the official interpretation of ASHRAE or GBCI?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5911 thumbs up
August 2, 2017 - 10:33 am
See the User's Manual for 90.1-2010 on page G-24. It very clearly states existing systems are modeled identically.
So ASHRAE is clear IMO. Now in future versions of 90.1 they do change this to the baseline according to Appendix G in all cases. That is also pretty clear.
Unfortunately GBCI has not been so clear to its users. Apparently many LEED projects have been allowed to/told to use the Appendix G Baseline instead of modeling the systems identically. There is confusion among the reviewers on this subject and I understand it is being discussed on our next reviewer call. So I think that currently you could do either one and it should be accepted.
Luis Andrade
3 thumbs up
February 6, 2019 - 8:16 am
Hello,
When alterations are to be made in existing facades (insulation installation, but retaining all structural components) how should they be modeled in the baseline building? Table G3.1, part 5, baseline building clearly states that it should not be the same as new contruction, but it is unclear for me on how it SHOULD be modeled: "Opaque assemblies used for alterations shal conform with section 5.1.3".
Can someone please advise me?
Thank you in advance!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5911 thumbs up
February 6, 2019 - 9:47 am
For existing assemblies follow Table G3.1-5 Baseline (f) which tells you to model the existing conditions in the baseline.
Luis Andrade
3 thumbs up
February 7, 2019 - 12:10 pm
Thank you Marcus!
Let me be more clear about the question:
Our project will be a renovation of an old warehouse (unconditioned) such that only about 20% of the exterior wals will stay (everything else will be new construction, incluiding floors, roofs, fenestration, HVAC equipments, lighting, etc...). LEED v4 Reference Guide, page 354, table 3, Existing envelope states that "(...) for an existing building (or spaces in the building) that was previously unconditioned and is renovated to include conditioning, the baseline building envelope (..) must be modeled as if the building is new construction." - This clarifies my previous question.
Now my new question: knowing that only about 20% of the building's exterior walls will remain, how much can we claim our project to be a major renovation and not a new construction? This is important so that we may claim additional credits under "Optimize Energy Performance" (Major renovation with lower % cost reduction to achieve points).
Thank you in advance!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5911 thumbs up
February 7, 2019 - 12:20 pm
Since the building was previously not conditioned I do not think you can claim the baseline as uninsulated at all as stated in the Reference Guide. You should use the Table 5.5 minimums in the baseline.
Luis Andrade
3 thumbs up
February 7, 2019 - 12:29 pm
Hi Marcus,
I agree!
How about my second question? May I consider the project as a Major Renovation (and not New Construction)?
Thank you!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5911 thumbs up
February 7, 2019 - 12:54 pm
Hard to say without seeing the configuration of what was there, what will stay, and what is getting built. If you are demoing 80% of the walls, all the roofs and floors then this certainly sounds like new construction to me. If what you are saving is a mostly enclosed and distinct area then maybe you could count that part as existing. Maybe you could try to justify doing a whole building take-off (wall, windows, roof and floor area) and then claim the percentage of existing wall as the percent existing? The conservative approach would certainly be to count it all as new construction. Anything else you will need to be able to justify to the reviewer.
Sara BENLOUBA
Green building managerConfidential
13 thumbs up
February 5, 2020 - 11:16 am
Dear Marcus,
Could you tell us if it is mandatory that the thermal coefficients of my building comply with table 5 - 5.3 which governs the performance of each type of envelope?
I'm lost, I'm on a project outside the United States.
Sara BENLOUBA
Green building managerConfidential
13 thumbs up
February 5, 2020 - 11:16 am
Could you tell us if it is mandatory that the thermal coefficients of my building comply with table 5 - 5.3 of ASHRAE 90.1 which governs the performance of each type of envelope?
I'm lost, I'm on a project outside the United States.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5911 thumbs up
February 5, 2020 - 1:19 pm
Only the X.4 sections of 90.1 contain the mandatory provisions.