scope:

Advanced Energy Design Guide for Multifamily Buildings-Achieving Zero Energy 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.

The Guide provides user-friendly guidance for the construction of new multifamily buildings, much of which 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. Meeting local code minimums and requirements will still be required in the improved design. Because there are many pathways to zero energy and, as technologies improve, more pathways will be developed, this Guide provides ways, but not the only ways, to achieve energy-efficient and zero energy buildings.

This Guide cannot specifically address all possible configurations of buildings. The recommendations therefore primarily apply to multifamily buildings covered by ANSI/ASHRAE/IES Standard 90.1 (ASHRAE 2019) up to twenty floors. While the recommendations may be applicable to taller buildings, the energy loads for buildings over 20 floors are more dominated by the vertical transportation (elevators), which changes the EUI targets for such buildings. This Guide covers buildings with independent tenant living spaces with units ranging from one to three bedrooms, where each unit has a kitchen space, bathroom(s), bedroom(s), and living spaces. A first floor containing common meeting spaces, a workout room, and staff/management offices or containing low-energy-density mixed-use spaces such as light retail and leased offices is also covered. The Guide also includes consideration of vertical transportation and laundry facilities, as well as energy management systems and controls. The Guide does not consider specialty spaces with extraordinary heat generation, large ventilation requirements, food service, pools, vehicle or other maintenance areas, domestic water well pumping, sewerage disposal, medical equipment as found in skilled nursing facilities, or smaller residential buildings not covered by ASHRAE/IES Standard 90.1.

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 as required to achieve the low EUIs needed to reach zero energy can often be challenging. With that in mind, owners should seize opportunities to move buildings toward zero energy whenever significant changes are made to their facilities. Any time a design decision is made is an opportunity to save energy. Changes may include replacement of a boiler, replacing light fixtures, or simply painting the space. Design decisions can be made that will reduce the energy impact of the building. One of the icons next to the how-to strategies in Chapter 5 (and described later in this chapter) indicates strategies that are particularly well suited for existing buildings to be renovated or modernized. See the How to Use This Guide section of this chapter for a description of the icons used in the Guide.

While this Guide focuses on reducing energy consumption in a building, there are also other important aspects of sustainability. Acoustics, IAQ, water efficiency and quality, land-scaping, access to views, and effective space planning are just some of the other benefits of an effective design. The objective is to create a zero energy building that is cost-effective and also designed with all these parameters in mind.