Washington DC’s Green Area Ratio Rule requires all new buildings that require a Certificate of Occupancy must meet the appropriate Green Area Ratio (GAR) based on the zoning district. The GAR is the ratio of the weighted value of landscape elements to land area. The score of landscape elements is calculated by multiplying the area of each element by its multiplier value and adding the scores together. Landscape elements include: soil and amendments, bioretention, new and existing planting, trees, vegetated walls and roofs, and more. Vegetated roofs must have a minimum of 5-7 species and no more than 20% of the total vegetated roof can be individual native species. Plants should achieve minimum 80% coverage after 2 years. There must be minimum 2 succulent plugs/square foot or 10 lbs of cuttings/100 square feet. Designs must include supplemental water. Green walls must include 1 cubic foot of soil/10 square feet of green façade.