The simplest way to optimize occupant comfort is to provide occupants with the greatest range of controllability over environmental conditions as possible, allowing occupants to adjust their surroundings or seek out spaces conducive to their working patterns and personal comfort levels. Thermal zones and individual lighting controls allow occupants to alter their thermal and lighting environment respectively. Operable windows integrated with the HVAC system may allow occupants control over ventilation and temperature. Consider designing for natural daylight with glare control and photosensor controlled electric lighting. Providing mobility, through wireless internet connections and mobile office equipment, gives even greater flexibility.

If renovating a building in stages, the order in which you make these upgrades will affect your long-term energy and water savings as well as your up-front costs. The ENERGY STAR Building Upgrade Manual walks you through a five-stage approach to minimize cost and maximize effectiveness. These stages include retrocommissioning, lighting upgrades, supplemental load reductions, air distribution system upgrades, and HVAC upgrades. See Building Systems Upgrades for guidance on improving building energy use, building water use, and occupant comfort. Use the Cost Effective Upgrades Tool to identify high-performance improvements based on your building's size and climate zone.

Building automation consists of a computer-based system with integrated measurement sensors and control devices for components such as HVAC equipment, lighting, and renewable energy systems. Building Automation Systems (BAS) are a common form of energy management and information system (EMIS). Monitoring and controlling building systems allows building owners to identify opportunities for improved performance by tracking energy and water use, ventilation and other elements of IEQ, security and other operations. Investing in a BAS can realize significant savings:

• Consider synergies among building systems.
• Employ ongoing commissioning practices to ensure building systems are properly calibrated and maintained over their lifespan.
• Use data to address areas of concern.

Building automation is interrelated with energy efficiency, water efficiency, ongoing commissioning, systems level metering and lighting control. Consider these strategies and other cost-effective upgrades:

• Occupancy sensors save energy by turning off some HVAC functions when no occupants are present in a space. Occupancy sensors are often connected to lighting, HVAC and security control systems to display continual energy use data for verification and occupant education purposes.
• Multi-zone HVAC systems reduce energy consumption while providing occupants more control of thermal conditions such as temperature, humidity and air speed. Consider dividing space into multiple and manageable zones according to use requirements, size, and location. Thermal comfort can also be enhanced by using a ventilation terminal control system with multi-zone VAV box terminal controls and individual airflow controls.
• Demand-control ventilation provides just enough outside air to meet the health needs of the occupants. Outside air is expensive to condition, so during times where few people are in a space (as determined by CO2 monitors), less outside air is delivered. These systems work particularly well for conference and multipurpose rooms, where occupancy fluctuates throughout the day.

In addition to providing insulation that may reduce the building’s heating and cooling loads, a planted roof can further improve the energy efficiency of the HVAC system in the summer if air intakes are placed around vegetated areas that have already lowered the ambient outdoor temperature. Ensure that reductions to the heating and cooling loads from the planted roof are considered in the design or upgrade of the HVAC system.

While reflective roofs, or “cool roof” systems, can save energy by reducing cooling loads, a planted roof can provide additional benefits, such as managing stormwater and providing greenspace and habitat. Plant selection should require no or minimal supplemental water. If supplemental water is required, consider alternative water sources for irrigation. While making changes to the roof, consider installing a solar thermal hot water system, which can yield significant energy savings. Save more on water heating costs by heating less water: high-efficiency plumbing fixtures, like low-flow showerheads, toilets and urinals, and high-efficiency faucets with sensor controls, save both energy and water. The reduced demand at the fixture paired with the free heat from the sun may enable the installation of a smaller boiler and pumps, saving on both first costs and operating costs.

Ensure that spaces designated for centralized collection of waste and recycling are ventilated adequately and that all waste and recycling collection equipment is cleaned and maintained on a regular basis. Special care must be taken to control pests and odors. Ensure routine collection from compost containers, which should be air-tight (some have carbon filter lids) to prevent unwanted odors and pests. Consider spaces where sensitive activities take place or that serve vulnerable populations, such as Child Care Centers. Ensure these spaces are located a safe distance away from centralized collection of waste and recycling and that these areas do not share common space or HVAC systems.

Several measures can help ensure high quality indoor air by limiting harmful airborne contaminants, such as volatile organic compounds (VOCs), mold spores and particulate matter. 

• First, control pollutant sources: integration of low-emitting materials and entryway systems with comprehensive Healthy Cleaning, Integrated Pest Management, and IEQ maintenance plans will help prevent contaminants from being introduced to the space.
• Second, provide adequate fresh air through proper ventilation. While increasing the ventilation rates of the HVAC system is the easiest way to replenish indoor air, it can use additional energy. Balance IAQ with energy efficiency by installing CO2 sensors at strategic locations to ensure that adequate ventilation is available based on space occupancy and use, but only when needed (also known as Demand Control Ventilation). Natural ventilation approaches can also help achieve good indoor air quality while minimizing additional energy use.

Human behavior can contribute to system efficiencies and implementing an ongoing occupant education program can be the most cost-effective means of reducing energy consumption. Green Teams can advance these efforts by educating fellow occupants and promoting sustainable practices. Obtaining the active participation of building occupants coupled with thermal comfort controls, as well as sensors that detect occupancy and ventilation requirements, can reduce overall energy use and provide better occupant comfort. Clearly communicate energy reduction and IEQ goals, meter energy use, and share energy use data with occupants. Provide a means for occupants to report malfunctioning sensors, controls, and other issues so corrective action can be taken.