Employ a layers of light approach which uses daylight for basic ambient light levels while providing occupants with additional lighting options to meet their needs. Set lighting goals (i.e., set a maximum Lighting Power Density goal and a daylight sufficiency goal) early in the project and craft a lighting strategy to achieve them. Utilize daylight harvesting best practices to supply ambient daylight to the space, and build upon this baseline with techniques and technologies to supply occupants with additional lighting options. 

Large windows can provide daylight to interior spaces, but the daylight can be best used when complementary technologies are employed. Lighting controls can automatically turn off overhead lighting in response to sufficient daylight. Dimmers designed specifically for fluorescent or LED lighting can also be incorporated into this control scheme, providing a gradual transition between natural and artificial light throughout the day. Light shelves can help reflect light deeper into the interior of the space, making the best use of a window’s area. Exterior shading or overhangs can let more light in the space during the winter, when heat from the sun is needed, and block higher-angled light in the summer, decreasing cooling loads. Window coatings also have an impact on the amount and color of light entering your building. Occupants seated near windows may experience glare on computer monitors and be tempted to close blinds, cutting off daylight to those in the interior of the building. Provide these employees with glare-reducing filters for computer monitors so that use of blinds is reduced.

When designed and installed together, this bundle can decrease the electricity needed to provide adequate and high-quality light to your space. When replacing fluorescent tubes with LEDs, consider replacing the entire fixture to maximize energy efficiency, product life, and to ensure safety.  When retrofitting LED tubes in fluorescent fixtures, use an LED tube with an integrated driver to avoid incompatibilities with the fixture that could shorten the product life or deliver unsuitable light quality. Occupancy sensors should be considered for all spaces that are potentially often vacant such as conference rooms, storage spaces, restrooms, lunch/breakrooms, and enclosed offices. Spaces used in common by tenants or visitors are primary candidates for occupancy sensors. Manual overrides are an important feature for these sensors, as employees may wish to turn off the lights for presentations or to use daylight. Dimmers specifically designed for fluorescent or LED lighting are available and can add controllability for occupant comfort and energy savings. Conference rooms are frequently built with both fluorescent lighting and dimmable incandescent lights for different room needs. Instead, consider dimmers built specifically for LEDs or fluorescent lighting that may eliminate the expense of installing the secondary incandescent lights in these applications. The choice of wall, carpet, ceiling, and furniture colors has a great impact on lighting quality. Choose colors that are easy on the eye while reflecting as much light as possible.

Optimizing comfort leads to happier occupants, every day of the week. The simplest way to ensure occupants are comfortable is to provide the greatest range of controllability over environmental conditions as possible. This controllability allows occupants to adjust their surroundings or seek out spaces conducive to their working patterns. Thermal zones and task lighting allow workers to alter their thermal and lighting environment respectfully. Consider using natural daylight with photosensor controlled electric lighting to create an effective and properly illuminated indoor environment. Providing mobility, through wireless internet connections and mobile laptops, gives even greater flexibility.

When upgrading your lighting system, consider the bulb lifespan and the waste stream generated by burnt-out bulbs. Fluorescent tubes and compact fluorescent lamps (CFLs) require special handling due to their mercury content. Light-emitting diode (LED) fixtures have a higher first cost, but have a longer life and do not contain mercury (a toxic metal).

Looking at fixing up the whole building, at once or in parts? If so, 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. Read more in the Building Upgrade Manual.

Building automation consists of a computer-based system with measurement sensors and control devices for components such as HVAC equipment and lighting. Monitoring and controlling systems around and within a building allow building owners to track energy and address areas of concern, providing opportunities for improved equipment and energy efficiency. Monitoring ventilation helps maintain healthy indoor environments. It is important to employ re-commissioning and continuous commissioning practices to ensure the building systems are properly calibrated and maintained over the life of the system. Investing in a building automation system can realize significant energy savings if equipment is performing as intended and building systems synergies are considered. HVAC building automation is inter-related with energy efficiency, continuous commissioning, systems level metering and lighting control. Consider investing in these HVAC specific systems:

• Occupancy sensors save energy from the operation of HVAC systems by turning off some HVAC functions when no occupants are within the building zone. The HVAC sensors are often combined with lighting 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 effective thermal conditions such as temperature, humidity and air velocity for occupants. Consider dividing space into multiple and manageable zones according to use requirements, size, and location. One solution for providing quality thermal and ventilation comfort is enhanced 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 with conference or training rooms, where occupancy fluctuates greatly throughout the day.