There are several types of Green Development Standards.
- Mandatory verses points. Mandatory GDS requires that the builder meet specific targets. (ie: plant trees). The Point based system says that a builder must score a set number of points and they can do so by selecting from list (ie: plant trees or use LED street lighting). Experience has shown that the builder usually selects the cheapest item and, therefore, mandatory targets are preferred.
- Tiered system. A tiered system is usually mandatory and starts with a fairly simple Tier 1 (plant trees and use LED street lighting) and progressing to a more onerous Tier 4 (buildings must be Net Zero). The requirements for each Tier is published as well as the time line for the next Tier to become mandatory.