The percentage of undeveloped land that must remain undisturbed for the Green Infrastructure and Buildings Credit on Minimized Site Disturbance is determined by the density of the project. Higher-density projects are generally permitted to disturb a greater portion of the land because they use the land more efficiently, while lower-density projects must preserve more undeveloped land to minimize the environmental impact. LEED encourages high-density development as a means to preserve open spaces and reduce sprawl, which directly influences the required percentage of land that must remain undisturbed.

References:

LEED v4 Neighborhood Development Guide: This guide details the requirements for minimizing site disturbance, explaining how project density affects the percentage of land that must remain undisturbed (USGBC, LEED v4 Neighborhood Development Current Version).

LEED Reference Guide for Neighborhood Development: Provides the rationale behind varying land disturbance allowances based on project density (USGBC, LEED Reference Guide for Neighborhood Development).