To document this credit for our LEED 2.1 project we are using the LEED 2.0 calculator, which discounts any space over 200 s.f. that has only one lighting control or one operable window. The LEED 2.1 credit requirement says to provide these controls "on average" for every 200 s.f. of space. If, for example, we have one individual office space of 180 s.f. and one of 220 s.f., each containing one control and one operable window, do these rooms comply with this credit since the "average" meets one for every 200 s.f.? If so, and the 220 s.f. space serves either one or two people, would this "average" still comply?
The project is inquiring if the calculations for this credit can be done based on an average number overall (of operable windows and lighting controls) for the project, rather than on a per space basis. As noted in the credit requirements, projects must provide "at least an average of one operable window and one lighting control zone per 200 square feet" of the perimeter area. The proposed approach is therefore acceptable. Please also refer to the LEED-NC v2.1 Reference Guide page 286-290 for further guidance on calculating the various types of spaces. Applicable Internationally.