Co-Benefits of Net Zero Investments for Human Health and Performance at Naval Installations
Creators: name: Petralia, Andrew
Publisher: name: Carnegie Mellon University
Year: 2023
Subjects: Architectural Science and Technology (incl. Acoustics, Lighting, Structure and Ecologically Sustainable Design)

description: The Energy Independence and Security Act of 2007 and recent executive orders signed by President Obama mandate that federal agencies achieve ambitious sustainability and environmental goals. As the largest consumer of energy in the federal government, the Department of Defense is making impressive gains in resource conservation and environmental preservation. Furthermore, the Secretary of the Navy has ordered that 50% of all Navy and Marine Corps bases are required to operate as net zero installations by 2020. As a result, considerable funding is being directed towards energy, water, and waste systems on naval installations. Existing facilities are being updated to meet modern sustainability standards while the design of new facilities is based primarily on high performance building strategies. 
Many of these strategies offer opportunities to optimize human health, wellness, and productivity on the path to net zero. Compared to the roughly $1 billion the Navy spends on operational and installation energy each year, over $45 billion is required to maintain the fleet of 500,000 active-duty sailors and marines, and over 200,000 DON civil servants. This does not include the billions of dollars spent annually on training, healthcare, fitness, and mental health treatment. 
Unique occupational stressors take a heavy toll on the mental and physical wellbeing of personnel. DOD-wide, medical care represents 7% of the total defense budget (OUSD, Comptroller, 2015) and is considered the number one uncontrolled cost factor, (NMCPHC, 2012). As much as 26% of active-duty personnel suffer from significant work stress (Pflanz &amp; Ogle, 2006), and 2.5% have been diagnosed with post-traumatic stress disorder (DCE, 2015). Astonishingly, almost 13% of active-duty naval personnel are considered obese, (Smith, et al., 2012), and 2.2% fail the Physical Readiness Test (PRT) every cycle, resulting in administrative separation of an average 980 sailors per year, (NMCPHC, 2012). 
In many cases, relatively minor investments in naval facilities can return human benefits valued at 2 to 3 orders of magnitude greater than energy and environmental savings alone. A growing body of research is documenting the significant effects that environmental factors have on the human condition. Carnegie Mellon University’s Center for Building Performance and Diagnostics Building Investment Decision Support (BIDS) tool demonstrates the economic impacts of such design strategies through case studies and empirical research. Organizations like Terrapin Bright Green, LLC., the Center for Active Design, and the International WELL Building Institute offer design guidance that seeks to optimize health, physical activity, and worker productivity in the built environment. 
This research establishes a baseline for comparing human health and performance benefits against energy and environmental benefits at naval installations and presents quantified assessments of top recommended net zero investments in building enclosures, lighting, HVAC systems, circulation, and water systems. 
At the building enclosure, green roofs or living walls reduce peak cooling load, mitigate stormwater runoff, and reduce urban heat island effect. Even for an already well insulated building or for locations that receive less rainfall, green roofs can be cost effective when the human benefits are considered in the payback equation. Chiefly, green roofs offer an opportunity for nature access and biophilic design in dense urban environments that may otherwise be devoid of natural elements. If accessible by building occupants or visible from seated positions within a neighboring facility, green roofs can reduce absenteeism by 10-16%, reduce sick building syndrome complaints by 15% (Elzeyadi, 2011), and improve cognitive performance by 10-25% (Heschong Mahone Group, 2003). Many hospitals and mental health treatment facilities are leveraging green roofs to provide controlled therapeutic gardens or activity space. Health and productivity benefits combined, seated access to a green roof view is valued at approximately $2,350 per baseline DON employee, per year. 
For façade glazing, appropriate dynamic shading strategies can mitigate glare and unwanted solar heat gain. External louvered systems or micro-slat blinds can redirect daylight and shave up to 30% on combined heating and cooling loads, (Palmero-Marrero &amp; Oliveira, 2010). For the employee, glare control can restore up to 15% of task performance for occupants who were previously disabled by high-glare workstations (Heschong Mahone Group, 2003). In addition, effective shading strategies can save roughly $250 per employee per year in headache-related presenteeism and sick leave. 
Perhaps the strongest correlation between energy conservation and human performance, daylighting can cut electric lighting loads in half (GSA, 2009), while increasing the amount of time spent on work-related tasks by 15% (Figueiro, Rea, &amp; Stevens, 2002), and reducing sick leave by 11% (Elzeyadi, 2011). For inpatients recovering at a naval hospital, day-lit patient care rooms can reduce the average length of stay by 6.5% (Joarder &amp; Price, 2013), saving about $575 in direct medical costs per patient. For a baseline naval hospital that serves almost 5,000 inpatients per year, this amounts to over $2.7 million in annual savings. 
For electric lighting, one consideration is critical for both energy and occupant performance: individual controls for task and ambient lighting. Occupants often perform work-related tasks more efficiently and report being more satisfied with indoor environmental conditions when given control over lighting levels at the workstation. Often, those with dimming control selected lower overall light levels than those provide by building automation systems or centralized controls, (Jones &amp; Gordon, 2004). 
Although not directly an energy concern, two other lighting considerations are critical to optimizing IEQ: color temperature and color fidelity (CRI). Short-wavelength, high CCT lighting exposure during the day has been shown to trigger greater circadian response, increasing alertness, concentration, and sleep quality (WELL, 2015), (Mills, Tomkins, &amp; Schlangen, 2007), (Viola, Lynette, Schlangen, &amp; Dijk, 2008), (Shamsul, Nur Sajidah, &amp; Ashok, 2013), (Keis, Helbig, Streb, &amp; Hille, 2014). Conversely, long wavelength, low-CCT lamps have been shown to foster calming atmospheres and reduce stress. Regardless of color temperature, high color rendering index (CRI) luminaires should always be specified. Greater color accuracy improves mood and occupant satisfaction. Whenever lamps are being replaced or upgraded, careful consideration should be applied to these specifications.
Thermal comfort and air quality are among the most influential contributors to occupant perception of IEQ. Considerable energy savings and significant occupant benefits can be realized through a hybrid approach of natural ventilation and supplementary mechanical cooling. Buildings with mixedmode conditioning systems offer the best of both worlds and have consistently received higher ratings for perceived IEQ and occupant satisfaction than conventionally cooled buildings, (Brager &amp; Baker, 2009). Increased rates of ventilation, higher air quality, and individual control of thermal comfort, all characteristics of mixed-mode conditioning systems, have been shown to improve overall productivity by almost 2% (Leaman, 1995), (Wargocki, Wyon, &amp; Fanger, 2000). 
As building enclosures and mechanical systems are continuously improved, ancillary building equipment and plug loads are representing increasingly significant end uses of energy. Since the advent of the elevator, mechanical equipment has dominated building circulation in commercial buildings for decades. By designing an open, convenient, and attractive circulation plan, elevator use can be reduced by 60%. More importantly, physical fitness and social collaboration are enhanced through a more active circulation strategy. For a baseline administration facility with 153 employees, a circulation plan that encourages stair use and physical activity nets over $58,000 per year in weight-loss and associated health risk reduction benefits. 
Lastly, at the building surround, water conservation measures to reduce irrigation present opportunities to provide occupants views and access to an outdoor natural environment. In lieu of non-native fescue grasses, drought-tolerant landscape design incorporates the use of naturally hardy vegetation, reinforces existing ecosystems, and reduces maintenance requirements. Native vegetation landscape design can be successfully integrated with outdoor nature paths or running tracks for fitness activity or walking meetings. Compared to the common turf-grass lawn, native vegetation often reduces irrigation requirements by 60% or more (Shapiro, Chan, Carson, &amp; Tayag, 2012). Furthermore, short walks in a natural setting has been shown to increase subjective vitality, creativity, memory, and attention, (Oppezzo &amp; Schwartz, 2014), (Berman, Jonides, &amp; Kaplan, 2008), (Ryan, et al., 2010). Combined, these benefits represent almost $2,000 in value per employee, per year at a baseline naval administration facility. Replacing water-intensive grasses with artificial turfs or pavement in an effort to reduce irrigation requirements, misses the opportunity to provide these benefits to personnel at naval installations....