scope:

Introduction

Building energy efficiency has been an important goal for decades, with one very notable period of activity during the energy crisis of the 1970s. During that period and since, much has been learned about howto improve energy efficiency in buildings. More recently, given increases in energy costs and concerns about the environmental impacts of buildings, there has been renewed emphasis on reducing building energy consumption. Climate change with the emissions of greenhouse gases associated with building energy consumption is one of the environmental impacts that has drawn the most attention (ASHRAE 2009a; Karl et al. 2009). At the same time as concerns about the environmental impacts of buildings and their associated energy use have increased, there has also been increasing concern regarding indoor air pollution as a significant factor in human health (DHHS 2005; WHO 2010).

The building community is challenged to reduce the environmental impacts of buildings, including energy consumption and associated greenhouse gas emissions, while maintaining indoor environments that are conducive to occupant health and safety. This overarching goal is often referred to under broader discussions of green or sustainable buildings. A number of programs, standards, codes, and other efforts are in place or under development to promote, and in some cases require, the design and construction of green or sustainable buildings (ASHRAE 2009b; USGBC 2009; GBI 2010; ICC 2010).More recently, there has been a focus on netzero energy buildings, which are intended to be so energy efficient that the energy they do require can be provided on an annual basis by on-site renewable sources (NSTC 2008). Some discussions of net-zero energy buildings also speak to the need for highperformance, which generally includes a range of non-energy performance attributes, such as indoor air quality (IAQ). Other performance issues include water use, material consumption, site impacts, and atmospheric emissions. Nevertheless, many discussions of green, sustainable, high-performance, and certainly net-zero energy buildings tend to focus on energy consumption, which, while critically important, is only one aspect of performance and should not be pursued to the neglect of the others. This article considers the role of IAQ in sustainable and other energy-efficient buildings and discusses how the goal of good IAQ can and should be factored into energy efficiency and other sustainable building goals. The discussion in this article is focused on commercial and institutional buildings, rather than residential, butmany of the ideas apply to residences as well. However, an analysis of the role of IAQ in residential sustainability and energy-efficiency programs, similar to what this article does for commercial and institutional buildings, is needed. associated with building dampness and mold), colds and other infectious diseases that are transmitted through the air (ASHRAE 2009c), and "sick building syndrome" symptoms due to elevated indoor pollutant levels as well as other indoor environmental conditions (ASHRAE 2009d). These more widespread impacts have the potential to affect large numbers of building occupants and are associated with significant costs due to healthcare expenses, sick leave, and lost productivity. Fisk (2000) estimated that potential reductions in healthcare costs, reduced absenteeism, and improvements in work performance from providing better IAQ in nonindustrial workplaces in the U.S. could be tens of billions of dollars annually. Despite these significant impacts, many building design and construction decisions are made without an understanding of the potentially serious consequences of poor IAQ and without the benefit of the well-established body of knowledge on how to provide good IAQ (ASHRAE 2010a).