Our multi-building LEED-CS v.2.0 project located in a dense urban area consists of one contiguous site. The project is scheduled in two construction phases and is registered as two separate LEED projects. The first project (Phase 1) consisting of an office tower, hotel and underground retail will be constructed over two years and the second (Phase 2) with two additional office towers is scheduled for completion three years later. We are targeting most of the site credits through a campus approach since all of the buildings have been designed to be components of the whole site. The buildings will be connected through plazas and green space, rendering the partitioning of the whole site into two project sites rather difficult. Additionally, each building will have a portion of its roof as vegetated and the truck ramp leading to the shared underground parking will also have a vegetated roof. It is our intention to use the campus approach for credit SS-5.1, (Reduced Site Disturbance - Protect or Restore Open Space) and reference a CIR dated 7/23/06 which stipulates that when vegetated roofs are included in the calculation a minimum of twenty (20%) percent of the total site area is needed to earn the credit. Our proposed approach is to combine all of the green areas on the site, including all vegetated areas on the building roofs for both Phases 1 and 2, thereby incorporating all green areas in our calculation for both phases. Please rule on the acceptability of this approach.
This inquiry requests clarification of calculation requirements for projects using green roofs in a campus setting. The CIR references a similar CIR dated 7/23/2006 under LEED-NC v2.2, which allows urban projects using green roofs to calculate the required open space area based on 20% of the TOTAL site area rather than on 50% of the site area excluding building footprint, and seeks to expand this alternative calculation method to projects using the Core and Shell system as well as to projects using the campus approach defined in the Multiple Buildings Application Guide. This is an acceptable alternative calculation approach. Note that in order to use this approach, the project must achieve SSc2 to include green roofs in the calculation. In addition, plants must be native or adapted as described in the credit requirements. Applicable Internationally.