Green Area Ratio (GAR) is the ratio of the weighted value of landscape elements to land area. The GAR score relates to an increase in the quantity and quality of environmental performance of the urban landscape. GAR sets integrated environmental requirements for landscape elements and site design that contribute to the reduction of stormwater runoff, the improvement of air quality, and the mitigation of the urban heat island effect.


The purposes of the GAR regulations are to:

  •  Implement a value-based system of requirements for environmental site design that provides flexibility in meeting environmental performance standards; and
  • Promote attractive and environmentally functional landscapes

The following guidelines can be found in Subtitle C, Chapter 6:

  • General guidance about the regulation of GAR requirements;
  • The applicability of GAR;
  • The formula for calculating the GAR and the definition of its component parts;
  • Landscape elements that are included in the GAR, an explanation of how their area is measured, and eligibility conditions;
  • Multipliers for each eligible landscape element;
  • An indication of what plans and certifications must accompany an application submitted to demonstrate proof of GAR compliance; and
  • Maintenance requirements for the landscape elements that are provided as part of a property’s GAR requirement.

For more information on the following topics, please see the corresponding referenced sections: