ASHRAE - 90459
Advanced Energy Design Guide for Small to Medium Office Buildings— Achieving Zero Energy
|Publication Date:||1 May 2019|
This Guide was developed through a collaboration of ASHRAE, The American Institute of Architects (AIA), Illuminating Engineering Society (IES), U.S. Green Building Council (USGBC), and the U.S. Department of Energy (DOE). A project committee that represents a diverse group of professionals and practitioners in HVAC, lighting, and architectural design as well as building owners drafted the guidance and recommendations presented herein.
The Guide provides user-friendly guidance for the construction of new small to medium office buildings. Much of the guidance also applies to retrofits of existing buildings, depending on the depth and breadth of the retrofits. The guidance addresses processes, polices, strategies, and technologies and includes energy-efficiency targets and how-to strategies. The recommendations in this guide are voluntary and are not designed to be code-enforceable. As a result, they are not intended to replace, supersede, or circumvent any applicable codes in the jurisdiction within which a building is constructed. In addition, there are many pathways to zero energy and, as technologies improve, more pathways will be developed. Therefore, this Guide provides ways, but not the only ways, to achieve energy-efficient and zero energy office buildings.
While this Guide cannot specifically address all possible configurations of buildings, the recommendations apply to office buildings ranging from roughly 10,000 to 100,000 ft2 with a building height of less than 75 ft. Many larger office buildings are made up of sections in this size range, thus the guidance herein can be extended to larger buildings. The Guide does not cover process loads or atypical spaces such as those for food service or laboratories or other spaces with higher energy loads and ventilation requirements. Space types covered by the Guide include office areas, circulation spaces, storage areas, break rooms (with a refrigerator, ice machine, dishwasher, microwave, sink, small appliances, and vending), small data centers/ closets, workout rooms, and conference and meeting spaces. The Guide does not consider specialty spaces with extraordinary heat generation, large ventilation requirements, or pollution generation.
Much of the Guide may also be applicable to buildings undergoing complete or partial renovation, additions, and or changes to one or more building systems; however, upgrading existing exterior building envelopes to achieve the low EUIs needed to reach zero energy is likely to be very challenging. With that in mind, any time changes are made to a building, there is an opportunity to move that building toward zero energy. This may entail replacement of a boiler, changing out light fixtures, or simply painting the space. Design decisions can be made that will reduce the energy impact of the building. The icons next to the how-to strategies in Chapter 5 indicate strategies that are particularly well suited for existing buildings to be renovated or modernized. Any time design decisions are made is an opportunity to save energy.
This Guide focuses on reducing energy consumption in a building. There are also overlaps with other important aspects of sustainability. Acoustics, indoor air quality (IAQ), water efficiency and quality, landscaping, access to views, and effective space planning are just some of the other benefits of an effective design. The objective of creating a zero energy building that is cost-effective is designing with all these parameters in mind at once. All these create buildings for the future.