For the Materials and Resources Credit, Purchasing - Facility Maintenance and Renovations, there is no specified minimum amount of renovation or new construction work required. The project team determines what qualifies for this credit based on the scope of their project.

Legionella outbreak is a significant public health risk that must be balanced with water efficiency and chemical usage in every water treatment program. Legionella bacteria can grow in water systems, particularly in warm, stagnant water. If not properly managed, it can lead to Legionnaires' disease, a severe form of pneumonia. Therefore, while striving for water efficiency and minimizing chemical usage, it's crucial to ensure that the conditions do not favor the growth of Legionella.

To earn the Indoor Environmental Quality Credit for Green Cleaning - Custodial Effectiveness Assessment, facilities must conduct an assessment of their custodial operations using the APPA Leadership in Educational Facilities' Custodial Staffing Guidelines. The highest score a facility may achieve to meet this credit's requirements is 5.5, which represents a level of cleanliness that is orderly and conducive to the intended use of the space, balancing effective cleaning practices with sustainability considerations. Reference: The Indoor Environmental Quality section of the LEED O+M Reference Guide details the requirements for the Green Cleaning - Custodial Effectiveness Assessment credit, including the use of APPA's Custodial Staffing Guidelines to evaluate cleaning effectiveness.

To comply with the prerequisite, the project team must establish an ENERGY STAR Portfolio Manager profile for the building and enter the required information, such as building type, size, occupancy, and energy use. The project team must also share the profile with USGBC and achieve a minimum score of 75 or demonstrate a 20% improvement in energy performance.

LEED v4 Reference Guide for Building Operations and Maintenance, page 2111

LEED AP O+M Exam Preparation Guide, page 672

The LEED AP Operations + Maintenance (LEED AP O+M) V4.1 focuses on improving the sustainability of existing buildings that are fully operational and have been occupied for at least a year12. Administering an alternative transportation survey is appropriate when the daily average or typical peak number of visitors is at least 50% of the regular building occupants. This is because the survey aims to understand and improve the transportation habits of a significant portion of the people interacting with the building, which includes both regular occupants and visitors. By focusing on this group, the LEED AP can identify opportunities to encourage alternative transportation modes, thereby reducing the building's overall environmental impact.

LEED v4: Building Operations + Maintenance Guide | U.S. Green Building Council

LEED AP with specialty | U.S. Green Building Council

LEED certification for existing buildings and spaces

LEED O+M Certification & Credentials | Existing Buildings | GBES