An existing LEED certified building located on a college campus is eligible for LEED for Building Operations and Maintenance; Existing Buildings (LEED O+M: EB). This rating system applies to existing buildings that are undergoing improvement work or little to no construction. It focuses on measuring and improving the performance of building operations and maintenance practices in areas such as energy efficiency, water conservation, waste management, indoor environmental quality, transportation, and occupant satisfaction. To be eligible for LEED O+M: EB, a project must meet certain minimum program requirements (MPRs), such as having a reasonable site boundary, being in a permanent location on existing land, being fully operational and occupied for at least one year prior to certification application, and complying with environmental laws and regulations. References: LEED certificationfor existing buildings and spaces6; Maintaining certification7; LEED v4: Building Operations + Maintenance Guide4

Xeriscaping is a landscaping practice that uses drought-tolerant native and adaptive plants to reduce water use and maintenance. Xeriscaping also incorporates other strategies such as mulching, efficient irrigation, soil improvement, and appropriate design and zoning. By using xeriscaping, projects can conserve water, protect natural habitats, reduce stormwater runoffand pollution, and enhance the aesthetic and ecological value of the site. References: LEED v4 Reference Guide for Building Design and Construction, p. 123 1; [Xeriscape Colorado website]

Waste that is transported or diverted to landfills can have negative impacts on the environment, such as occupying valuable land, contaminating soil and water, and emitting harmful gases. One of the most significant impacts is the production of methane, a potent greenhouse gas that contributes to global warming and climate change. Methane is generated when organic waste decomposes anaerobically (without oxygen) in landfills. Methane has a global warming potential 28 times higher than carbon dioxide over a 100-year period12. References: LEED v4 Green Associate Candidate Handbook1, EPA's Landfill Methane Outreach Program2

According to LEED v4, the commissioning authority (CxA) should be contracted before the end of the Design Development (DD) phase and should be involved in the project team from early in the Schematic Design (SD) phase1.
References := LEED v4: Building Design + Construction Guide, LEED v4 -U.S. Green Building Council, SBGD - Part D - ConsultantScopes of Work 3. Commissioning Authority, What's new in LEED V4
- Commissioning Changes - Steven Winter ..., LEED ENHANCED COMMISSIONING | Steps and Downloads

LEED certification is awarded based on the number of points a project earns across several categories of green building performance. The range of points required to achieve LEED Silver is 50-59, out of a possible
110 points. The other levels of LEED certification are: Certified (40-49 points), Gold (60-79 points), and Platinum (80 or more points)12. Therefore, if a project initially has 34 credit points,it would need 20 additional points to reach the minimum threshold for LEED Silver. References: LEED v4 Green Associate Candidate Handbook1, LEED v4 BD+C Reference Guide2