We are computing energy performance for a major renovation project in the context of Core&Shell.
Modeling the proposed building model we are realizing some difficulties modeling the total building as demanded in LEED 2009 MPR.
The major renovation is carried out for approx. 70% of the building.
The 3 basement floors and the first floor of the scyscraper building will persist unchanged.
The narrow side of the building façade will persist unchanged too.
All floors above the first floor shall be renovated (HVAC, exterior wall, windows, roof, lighting).
The building standard of the 50 years old building (HVAC, construction, lighting) is mostly unknown. Documentation is very fragmentary and examination of the whole building is not very practicable.
So how should we model the HVAC, construction, lighting of the remaining part of the building which persist unchanged.
1) Should we use HVAC of basement building ?
2) Should we use construction of basement building ?
3) Should we use lighting of basement building ?
Is there any hint in ASHRAE 90.1-2007 App. G or the LEED Core&Shell guide ?
Has there been similar discussion in this board before ?
Thanks in advance.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
September 12, 2012 - 10:24 am
There has been some debate on this issue.
The Standard itself is silent on the issue except for the envelope (see Table G3.1.#5 Baseline (f)). So this would be an indication that you would model the non-renovated portions of the building as they exist for the proposed and model the entire baseline according to Appendix G (except for the envelope, see Table G3.1.#5 Baseline (f).
The User's Manual indicates that the existing HVAC conditions should be modeled identically in the baseline and proposed (page G-21).
No guidance is provided for the other building systems beyond HVAC and envelope.
Personally I think it is most fair to model the existing conditions in both but I can see the point raised by the other approach. Sorry I do not have definitive guidance. The conservative approach is the first one so that is most likely to be accepted by the reviewer.
You should get the information you need to do the model as accurately as possible in the most efficient manner possible. If the existing building is not recently documented then someone will need to survey it to determine the existing conditions.
heinrich post
dr.b+e
45 thumbs up
September 13, 2012 - 5:48 am
Thanks for your quick reply Marcus.
So my conclusion to the final part of your comment:
If there is no complete survey of existing construction, HVAC and lighting of the non-renovated part of the building we cannot use energy modeling to demonstrate energy performance of major renovation for LEED Core&Shell.
Am I right ?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
September 14, 2012 - 8:56 am
Yes, you would need to model the existing conditions and in order to do so you must know those existing conditions. If surveying the existing building is the only way to get that information then yes you would need to survey the building. Without this information you can't do the modeling.