Explanation
Occupancy sensors are devices that detect the presence or absence of people in a space and automatically turn the lights on or off accordingly. By installing occupancy sensors for thebuilding's lighting system, projects can achieve two benefits: improving the indoor environmental quality (IEQ) and reducing the energy consumption.
Occupancy sensors can enhance the IEQ by providing lighting control for individual spaces, allowing occupants to adjust the light levels to their preferences and needs. Occupancy sensors can also save energy by avoiding unnecessary lighting when spaces are unoccupied, thus lowering the electricity demand and greenhouse gas emissions. References: LEED v4 Reference Guide for Building Design and Construction, p. 507 1; LEED v4 Reference Guide for Building Operations and Maintenance, p. 241 1

LEED for Building Operations and Maintenance (O+M) is the rating system that applies to existing buildings and interior spaces that have been fully operational and occupied for at least one year1. It focuses on performance-oriented sustainable strategies and outcomes, such as energy efficiency, water conservation, waste management, indoor environmental quality, and transportation2. LEED O+M can help existing buildings reduce their environmental impacts and improve their operations1.

When developing the project and building construction budget, the project team should incorporate time in the schedule for unique materials and systems. This is because some green building strategies may require materials or systems that are not readily available or familiar to the local market. For example, using recycled or salvaged materials may require more time for sourcing and delivery. Similarly, installing renewable energy systems or high-performance HVAC systems may require more time for design and commissioning. Therefore, the project team should plan ahead and allocate sufficient time for these aspects of the project. Reference: LEED v4 BD+C Reference Guide, Integrative Process, page 28

Graywater refers to relatively clean wastewater from domestic activities such as washing dishes, laundry, and bathing. Water from lavatory faucets falls into this category. Graywater can be treated and reused for non-potable purposes such as toilet flushing or irrigation, which can help conserve water. Reference: LEED Green Associate Candidate Handbook, U.S. Green Building Council resources