Preface

This guide is the second in a series of planned Energy Efficient Guides for Existing Commercial Buildings (EEG-EB) developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) in collaboration with the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), and the U.S. Green Building Council (USGBC), and supported by the U.S. Department of Energy (DOE). While the first guide in the series provided the business case for improving energy efficiency, this guide provides technical guidance on how to increase a building's energy efficiency.

This guide is intended for building engineers and managers and assumes a working technical knowledge of building systems both generally and for the reader's specific building. The guide demonstrates ways to measure a building's energy efficiency, track that efficiency, develop an energy efficiency plan, and provides guidance on implementing the developed plan. The goal is to provide clear and easily understood technical guidance for energy upgrades, retrofits, and renovations, by which building engineers and managers can achieve at least a 30% improvement in energy performance relative to a range of benchmark energy utilization indexes (EUIs). The document provides practical means and methods for planning, executing, and monitoring an effective program, based on widely available technical strategies and technologies.

ASHRAE has a number of standards, guidelines, and design guides that provide guidance for constructing energy efficient buildings. This new guide dovetails well with these documents; yet, realistically, these other efforts primarily target new construction or, to a limited extent, portions of existing buildings undergoing major renovation.

The highly successful Advanced Energy Design Guide (AEDG) series provides prescriptive guidance for new building designs to achieve energy savings 30% to 50% beyond ANSI/ASHRAE/IES Standard 90.1. The building types covered by these guides include small to medium office buildings, retail buildings, K–12 school buildings, warehouses, highway lodging, hospitals, and healthcare buildings.

Unlike the new building guides, which were written by teams of volunteers from the collaborating organizations, the existing building guides are written by a contractor, under the guidance of an EEG-EB Project Monitoring Committee. In addition to the collaborating partner organizations, the Building Owners and Managers Association (BOMA) International and the U.S. General Services Administration (GSA) were also involved in the development of the guide and represented on the Project Monitoring Committee.

The existing building guides also address a wider range of issues than the new building guides. While the new building guides addressed only design issues, the existing building guides address, at some level of detail, analysis of current operations, renovation, retrofit, system or equipment replacement, operation and maintenance, as well as providing technical design input. These issues will be strongly dependent on the building type and age. And, virtually all existing buildings will first need to be brought up to minimum requirements before energy savings are pushed beyond minimum performance. A hierarchical approach based on the cost of conserved energy provides the basis for prioritized measure selection is presented in the context of life-cycle costing that encourages long-term investment horizons.

Clearly, the greatest opportunity for overall reduction in U.S. primary energy use lies within the existing building stock. That stock also represents a significant potential for real estate owners and developers to not only demonstrate sustainability initiatives, but also to realize a great return on the investment. This series of EEGs, in addition to other ASHRAE initiatives aimed specifically at promoting energy conservation and efficiency in existing buildings, will help building owners achieve the goal of building sustainability while increasing their return as energy prices rise.