Rating System

LEED BD+C: New Construction, LEED BD+C: New Construction, LEED BD+C: Core and Shell, LEED BD+C: Core and Shell

Rating System Version

v2 - LEED 2.2, v3 - LEED 2009, v2 - LEED 2.0, v3 - LEED 2009

Inquiry

The project is a high-rise residential building that is being applied under LEED-CS certification. Living units are being designed without air-conditioning system, since generally the people use natural ventilation during summer. Building spaces with regular occupation, such as bedrooms and living rooms, will be furnished with operable windows only, without mechanical systems. Therefore, under ASHRAE Standard 90.1 the entire building would be defined as unconditioned space, and the envelope does not need to comply with mandatory provisions of that Standard. Following this interpretation, the scope of work for this project would be limited to sections 7, 8, 9 and 10 of ASHRAE Standard 90.1, as the building will be provided with: service water heating; power distribution systems; lighting systems for common areas; and electric motors (stairs ventilators, water pumps and sewage pumps). In order to achieve the minimum energy performance prerequisite needed for LEED certification, only the lighting system for common areas and the service water heating were identified by the design team as the scope of work to be treated under ASHRAE Standard 90.1 and modeling rules of appendix G. This CIR is to clarify three questions: 1. Is this building eligible to certification under LEED, even without HVAC system? 2. If affirmative, the minimum energy performance has to be achieved only for those systems that will be provided by the owner, i. e., lighting system for common areas and service water heating? 3. Can natural ventilation be used as an energy efficiency strategy to achieve the minimum energy performance, in similar way as discussed in a CIR posted in 03/22/2007 (through an Exceptional Calculation Methodology)?