Since New York City has issued a set of policies regarding turning roofs eco-friendlier, the Green Roof law now requires buildings to either install a green roof system, or a solar photovoltaic system. The buildings that are bound to comply by this rule are those undergoing construction, any sort of renovation or being built from scratch. The law came into effect in November and conditioned that the roof of these buildings must be covered with green roof systems to the end, focusing more on buildings to be constructed. However, if a building is going through certain changes such as addition of floors or replacement of the roof, the laws are still applicable on them.

Confusions arose concerning the law conditioning roofs that are going through renovations, since most renovations normally include repairing the roof deck, and not replacing it entirely. Hence, the confusion was cleared that this law does not apply in this context. This not only clarifies for a lot of homeowners that their roof repairs do not require green roof or solar installations, but it has also led the Department of Buildings in giving out a memo which clearly mentions the details of the law for the New Yorkers.

As lawmakers start to focus on policies tackling climate change, this law is considered as one of the major attempts as it aims at achieving a forty percent reduction in the emission of greenhouse gases in the upcoming ten years. Furthermore, this law tries handling the rainwater runoff issues by installing green roofs, which absorb and release water slowly rather than allowing it to run off. It also addresses the urban heat island effect, since New York City has a higher temperature than its neighboring rural areas, therefore demanding more of an attention.

This promotes a betterment of sewage systems as well since the flow of heavy rain can be catered by the increased plant life on the roof of buildings. Therefore, not only is there a less likelihood of untreated sewage flowing through the rivers, but also increased greenery. Similarly, a rise in the installation of solar systems on roofs will make air cleaner and increase the solar capacity of the city.

Installation of solar panels also lead to decreased energy costs as a result of the sustainable roof and a better use of the building. In addition to that, green roof can be better installed on buildings if their roof is of thick concrete because it can lead to more sustainability of effective crop.

Certain exemptions that the law allows these buildings is to exclude the area of the roof which has mechanical equipment or terraces, while covering all the other available space. In order to incentivize the people to abide by the law, financial help is being provided to people through grants, loans, and tax abatements. Loans are also available for multi-family residential buildings and they are also offered a DEP reimbursement program, which requires applications from the building owners some time ahead of the installation of green roof or solar system.