Advanced Energy Design Guide FAQs

What is an Advanced Energy Design Guide (AEDG)?
The Advanced Energy Design Guides (AEDG) are a series of publications designed to provide recommendations for achieving either a zero energy building or energy savings over the minimum code requirements in ANSI/ASHRAE/IES Standard 90.1. A zero energy building is defined as a building that, on an annual basis, draws from outside resources equal or less energy than it provides using on-site, renewable energy sources.

Why was this series of Guides initiated?
ASHRAE gained recognition as an organizational authority on energy issues in the 1970s when it was asked to develop a national standard on energy conservation. We met that challenge, and the resulting standard now known as ANSI/ASHRAE/IES Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, continues to influence building designs worldwide. It has become the basis for building codes, and the standard for building design and construction throughout the U.S. Buildings built to current standards use significantly less energy than buildings built prior to the development of Standard 90-1975. While standards play a vital role in the construction industry, the language and format of standards limit their ability to provide guidance during the critical design process, and generally define "minimum" performance, instead of exemplary or design leadership. Design excellence has been an ASHRAE tradition, and there has been a great demand by our members and others for ASHRAE to continue playing a leadership role in developing material on designing and maintaining energy conserving buildings that goes beyond minimum standards of performance. The Advanced Energy Design Guide series of publications provides this type of guidance.

Who determines the scope of these projects?
An AEDG Steering Committee (SC) composed of four partnering organizations has been established and has the responsibility of approving the initiation and scope of a project and the final product of a Special Project (SP). The partnering organizations are the American Institute of Architects (AIA), ASHRAE, the Illuminating Engineering Society (IES), and US Green Building Council (USGBC). Following the establishment of new a Guide SP, the SC develops a well-defined scope and direction for the project. The SC works closely with the specific Guide Project Committee to respond to scope and policy-related issue questions during the development of the document and in the review process when additional issues relating to the scope are recommended. The U.S. Department of Energy (DOE) provides funding for the Guides through the national labs. Technical support is provided by the Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy Laboratory (NREL).

What is the objective of the Guides?
The Guides are educational guidance intended to provide a simple and easy approach to design and build energy efficient buildings for use by contractors and designers who design and construct the specific building types represented in the Guides.

What's the intended level of complexity in the Guides?
Because many of these buildings may use design teams without the modeling resources necessary to evaluate energy conserving alternatives, and many of these buildings are constructed via design/build firms or contractors, the Guides are intended to provide a simple and easy approach for use by contractors and designers. The recommendations provide a "pre-modeled" solution to achieving an energy-efficient building design.

What's the role of economics in determining the recommendations?
The role of, and whether and/or how economics were to be included, has been debated thoroughly by the Steering Committee (SC). The project definitions developed by the SC indicate that energy use is considered as the independent variable that is specified, and cost effectiveness (as measured for example by simple payback period) is the dependent or resulting variable; thus the zero energy status or the 30% or 50% energy savings beyond Standard 90.1 is the driver. That is, the objective of the recommendations is to respond to the building owner who plans on occupying the building for a long period of time and who wants recommendations on energy savings features beyond those measures that are generally considered to have a short payback period. This allows consideration of a package of installation ideas that might not be considered if a fixed payback period for individual measures was stipulated. Significant energy savings occur when the total energy picture for a longer time frame is evaluated rather than only picking the 'low hanging fruit' with short payback periods.

Why aren't the recommendations the same for all locations?
Climate greatly impacts the way energy is used in buildings. Recommending the same high-efficiency heating system in Miami as is recommended in Duluth, or recommending the same air-conditioning efficiency in Duluth as in Miami is neither reasonable nor practical as long as there are price differentials in levels of efficiency.

Are cutting-edge or specialized equipment and/or materials required to achieve the targeted energy savings?
No. To quantify the expected energy savings, potential envelope, lighting, HVAC and service water heating energy saving measures were selected for analysis and recommendation. Only measures and equipment that were deemed to be both practical and commercially available from at least two manufacturers were considered. Although some of the products may be considered premium, products of similar energy efficiency performance are available from multiple manufacturers.

Are the Guides considered ASHRAE standards or guidelines?
No. The AEDGs are Special Publications that provide some ways, but not the only ways, of achieving an energy-efficient building. They are not intended to be used as a standard or to specify minimum (or maximum) values. The documents are not written in code-intended language, and the format of the documents does not suggest use as a standard. They are educational guidance written to provide options for those wishing to exceed minimum performance.

Standards play a vital role in the construction industry. They represent a consensus on the way something must be done or measured, or theyrepresent the minimum allowable performance that must be achieved. However, the language and format of standards make it difficult for them to provide necessary education or guidance during the critical design process.

Will the Guides give all the answers and cover all cases?
No. The documents are not all-encompassing. They provide educational guidance and how-to advice on some ways, but not the only ways, to achieve the goal for a particular kind of building (eg. small offices). It is readily acknowledged that there are other ways not included which may accomplish the same targeted energy savings. The 50% guides go one step further and provide benchmarking and modeling guidance in the support of other design options. The zero energy Guides provide energy targets by climate zone and include guidance for incorporating renewable energy into the building design.

Will the Guides replace Standard 90.1?
No. The AEDG series contains recommendations and is not a minimum code or standard. It is intended to be used in addition to the existing codes and standards and is not intended to circumvent them. Each Guide is also only applicable to a specific type of building, vs. all non-residential buildings covered by Standard 90.1.

How are the reviews done on these Guides?
The integrity of the Guides is checked by a targeted peer review process. The review process is announced and discussed in many public forums including the ASHRAE web site. There are at least two peer reviews conducted for each Guide with participation requested from the partnering organizations and the relevant technical committees for the purpose of: identifying major conceptual concerns, identifying major technical issues, conducting technical refinement, and identifying factual errors. Specific dates for the review periods and the purposes of each of the reviews are announced and discussed in many public forums including the ASHRAE web site. The Steering Committee clarifies direction on issues raised during the peer review (e.g., recommendations made to expand the scope of the project or conflicting recommendations received from separate reviewers) and assesses the Special Project considerations and implementations of peer reviewers' recommendations.

What's the difference between an ASHRAE Standard, an ASHRAE Guideline and an ASHRAE Special Publication?
ASHRAE writes standards and guidelines in its fields of expertise to guide industry in the delivery of goods and services to the public. ASHRAE standards and guidelines follow a consensus process, include uniform methods of testing for rating purposes, describe recommended practices in designing and installing equipment and provide other information to guide the industry. Standards are written in code-intended language and are developed to define minimum values or acceptable performance. Other documents such as an ASHRAE Guideline or a Special Publication may be developed and published to encourage enhanced performance, educate the user, or provide additional information on a particular subject. Special Publications, such as design manuals, application guides, technical bulletins, etc., are developed outside of the formal standards making process, following rules established by the ASHRAE Board. The AEDG series are ASHRAE Special Publications.

What version of Standard 90.1 was used as the baseline for the Guides?
Buildings built to Standard 90.1 are used as a benchmark or a baseline for comparative purposes - analogous to the base year used for the consumer price index. The particular version of the standard used is not as critical as having a well-defined starting point and maintaining continuity between the various Guides in the AEDG series.

The 30% series of guides uses Standard 90.1-1999 as the baseline. The 90.1-2004 version was not approved before the initial 30% Guide was completed, so it was therefore not available to be used as the baseline. Subsequent 30% Guides used the same base in order to maintain continuity within the series.

The 50% series of guides uses Standard 90.1-2004 as the baseline. The 90.1-2004 version was the latest version for which DOE had completed their determination, so it was deemed to be the most appropriate version to use. Subsequent 50% Guides are using the same base in order to maintain continuity within the series.

The zero energy series of guides does not refer to a particular edition of Standard 90.1, as the goal of these Guides is to provide recommendations to achieve zero energy buildings.

How do the Guides relate to the U.S. Green Building Council's LEED or to the ENERGY STAR rating systems?
The AEDGs provide a path for achieving New Construction Energy & Atmosphere (EA) points in the LEED rating system. LEED credits may be obtained as a prescriptive path for adherence to the recommendations in the Guides. The specific points available for use of the Guides are specified in the LEED documentation and may vary by building type. More details are available at the USGBC LEED website.

ENERGY STAR rated appliances and equipment are recommended in the Guides; however, there is not a direct relationship with the ENERGY STAR rating for commercial buildings that requires an energy rating of 75 or greater to achieve ENERGY STAR certification.

What is the relationship between Standard 90.1, the AEDG series, and Standard 189.1?
ANSI/ASHRAE/ICC/USGBC/IES Standard 189.1, Standard for the Design of High-Performance, Green Buildings except Low-Rise Residential Buildings, is intended for buildings that wish to exceed the minimum requirements of ASHRAE/IES Standard 90.1. Standard 189.1 provides a “total building sustainability package” for those who strive to design, build and operate green buildings. From site location to energy use to recycling, this standard sets the foundation for green buildings by addressing site sustainability, water use efficiency, energy efficiency, indoor environmental quality, and the building’s impact on the atmosphere, materials and resources. Standard 189.1 served as a compliance option to the International Green Construction Code™ (IgCC) published by the International Code Council; in 2018 Standard 189.1 became the IgCC in North America. The IgCC regulates construction of new and remodeled commercial buildings. Standard 189.1 is still available outside North America.