Hello all,
Above the concrete roof of the project, there are the steel structure (about 10m high) with the perforated panels for wall and grid mesh at the top. The grid mesh has about 80% perforation. there are the cat ladder provision from the concrete rooftop to the top of the grid mesh roof. My question are:
1) does the concrete roof (10m below the grid mesh and well shaded with vertical perforated panels) need to comply with the SRI requirement?
2) does the cad ladder need to comply with the SRI requirement.
Appreciate your advice.
Thanks,
Grace
Mara Baum
Partner, Architecture & SustainabilityDIALOG
674 thumbs up
August 18, 2010 - 12:16 pm
The credit requires you to have at least 75% of the roof surface meet the SRI requirement. If I understand you correctly, then the mesh is only 20% solid, so this alone would not meet the requirement and at least part of the roof would have to comply. There are several CIRs under earlier versions of LEED that can give guidance on weighted calculations that take the shading into consideration.
Ladders and other appurtenances are not required to meet the SRI requirements.
Grace Ming
Senior ESD Consultant95 thumbs up
August 20, 2010 - 2:23 am
Thanks Mara for your advice.
Actually, most of the concrete roof slab has M&E equipments and pipes. Since the M&E areas are exempted from this requirements, we would like to exclude the concrete roof slab from SRI requirements. Another reason is that gird mesh is located at about more than 10m high above conc slab and the conc slab is well shaded by vertical perforated panels. So, we wonder if the reflectance of the roof slabs will have impact on UHI.
Any comment or suggestion? Thanks,
Mara Baum
Partner, Architecture & SustainabilityDIALOG
674 thumbs up
August 20, 2010 - 1:53 pm
There are two different questions here (unfortunately). The first is whether or not the roof has much impact on UHI. The second is how you're supposed to treat it for the LEED point. You're probably right that the concrete roof surface doesn't play a big role. For LEED, you still have to document that you're mitigating the UHI effect -- if not by the conventional mechanisms, then by an alternative compliance path that is equally or more stringent. The simplest way to do this is to determine how much of your roof is not M/E equipment, and make at least 75% of that area cool. Part of this strategy may also include making the mesh cool as well (e.g. painting that white).
I definitely recommend checking out the different CRIs for more specific guidance regarding the shading -- you'll better be able to figure out what applies to your circumstance.