Background: The Eastside Recycling center in Iowa City, IA will be a campus of 10 buildings / structures owned by the City of Iowa City. These buildings will provide public facilities for post-consumer recycling, materials re-use and sustainability education. As part of this campus, there will be 4 pre-engineered metal buildings. Each will be used for storage of recycled materials, electronic waste, materials to be re-used, and other miscellaneous storage. Only one of the 4 pre-engineered metal buildings has a dedicated office space which will be located in one corner of the building. The campus of buildings will be LEED certified using the LEED-NC for Multiple Buildings and On-Campus Building Projects. It is our intent to include these 4 pre-engineered buildings as part of the LEED certification. Proposed Strategy: In order to reduce energy consumption and simplify building maintenance, these 4 pre-engineered buildings will not be conditioned. Each building will have dedicated large-diameter overhead fans to circulate air, but there will not be a dedicated heating or cooling system. There will be a small office space in one of the metal buildings which will have an operable window as well as an electrical service outlet for a fan in the summer or electric space heater in the winter. These buildings would be defined by ASHRAE 90.1 as an unconditioned space, having less than 3.4 Btu/h*ft2 of floor area (both heating and cooling). As such, these buildings would not fall under the envelope requirements of ASHRAE 90.1. The minimum energy efficiency standards for EA Prerequisite 2 must comply with ASHRAE 90.1, and the performance rating calculations (using a whole building project simulation) for EA Credit 1 must comply with the Building Performance Rating Method in Appendix G of ASHRAE 90.1-2004. Because ASHRAE 90.1 does not apply to envelopes of buildings that are unconditioned space, the 4 pre-engineered buildings do not fall within the requirements of this standard. It is proposed to exclude the 4 pre-engineered buildings in the composite campus energy performance calculations in EA Credit 1 (Option 1) for the group of buildings to be LEED certified. As such, these 4 pre-engineered buildings would be excluded from the minimum energy efficiency levels required by EA Prerequisite 2. Interpretation: Is it acceptable to exclude these 4 pre-engineered buildings from the minimum level of energy efficiency requirements in EA Prerequisite 2 and the building performance rating calculations for EA Credit 1 (OPTION 1)?
The applicant requests clarification regarding whether unconditioned buildings may be excluded from the energy efficiency prerequisite (EAp2) and the energy efficiency performance rating calculations for EA Credit 1. If the buildings are included as part of the LEED scope of work, then they must be included in the energy calculations for EA Credit 1, and must meet the applicable portions of the referenced standard for EAp2. Specifically, the lighting for these buildings must comply with the minimum requirements of ASHRAE 90.1-2004. For EAc1, these buildings would be treated very similarly to unconditioned parking garages, where the envelope does not necessarily need to be modeled, but the electric loads from the lighting and fans are included in the energy calculations. Lighting in the baseline case should be consistent with the interior lighting power allowance in Section 9.2. Applicable Internationally.