We are working with a building that has 9 floors, the first 6 floors are for parking, unconditioned naturally ventilated with no glass on the envelope, and the last 3 are conditioned office spaces with a high WWR.
To model the baseline, should we consider the whole façades of the building (6 parking floors + 3 office floors) to calculate the 40%, or just the conditioned height (3 office floors)?
From table G3.1-5 it seems that the whole façade should be used to calculate the WWR: "40% of gross above-grade wall area, whichever is smaller,"
To select the Baseline HVAC system we are considering just 3 floors, as we understand, from Marcus´ comment previously posted, that only conditioned floors count.
Thanks in advance,
Anderson
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5916 thumbs up
August 20, 2014 - 5:31 pm
I will not disagree with myself, at least this time!
Jean Marais
b.i.g. Bechtold DesignBuilder Expert832 thumbs up
August 21, 2014 - 4:23 am
- It has been ruled (last I heard) that parking buildings are not LEED certifiable.
- It is said that the building should concider all parts that are needed for it's function...in your case I was thinking that the parking is not for the offices per say and should probably be excluded.
- The WWR rule applies only to surfaces where the proposed design has glazing. You can't put glazing where there isn't any in the proposed design.
Jon Clifford
LEED-AP BD+CGREENSQUARE
LEEDuser Expert
327 thumbs up
August 21, 2014 - 8:42 am
Clarification: On its own, an unconditioned, unoccupied parking garage is not eligible for LEED certification. However, a parking garage attached to a conditioned building and within the LEED project boundary may be certified as part of that project. In this case, all costs, materials, and activities associated with the garage must be taken into account for all credits & prerequisites.
That said, the window-to-wall ratio only applies to walls that enclose conditioned space, so the walls of an unconditioned garage must be excluded from this calculation.
On the other hand, for the energy models, one must include lighting, mechanical ventilation, & other loads associated with the garage, even though it is unconditioned.
Is that right, Marcus?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5916 thumbs up
August 21, 2014 - 10:03 am
You must model everything that impacts energy use within the LEED Project Boundary. You determine the project boundary within the confines of the MPRs.