Solar Panels + NYC New Construction | Solar + Green Roofs Now Required
Nov 15, 2019
by EmPower Solar
Following in the footsteps of California, New York City now requires sustainable roofs for new construction. As part of The Climate Mobilization Act, builders must incorporate green roofs or solar panel systems starting November 15, 2019. This shift falls in line with NYC’s Green New Deal goals to have one of the most sustainable skylines in the world.
Solar Panels + NYC New Construction: Solar + Green Roofs Now Required
Local laws 92 and 94 require that all new buildings in NYC have a sustainable roofing zone covering 100% of the roof. The law also applies to some existing buildings that undergo substantial changes, such as those needing the entire existing roof deck or roof assembly to be replaced.
What Are the Requirements for Local Law 92 + Local Law 94?
The sustainable roofing zone must include a solar photovoltaic system generating at least 4kW or a green roof system. Builders and owners also have the option to combine green roofs with solar to comply with the new local laws.
When it comes to solar, building and fire codes that can restrict systems from covering 100% of roof space. So “all available” roof space may be smaller than expected after code restrictions are met.
Varying site conditions, such as roof pitch, shade, and energy needs can also be deciding factors in going solar. When these conditions are not met and solar is not feasible, then a green roof system must be installed. For example, a heavily shaded roof would be categorized as having an “unfavorable site condition” and would default to a green roof, as most green roofs perform fine in shaded environments.
Exemptions for Local Law 92 + Local Law 94
If a building can not accommodate at least 4kW of solar, that would qualify as an “unfavorable site condition” and solar would not be required, but a green roof would need to be explored. Roofs that cannot accommodate either solar or a green system must still comply with cool roof standards.
Solar Photovoltaic Systems in NYC
Building emissions currently account for 70% of greenhouse gas emissions across NYC. Local laws 92 + 94 are a significant step toward meeting the city’s ambitious goal of becoming carbon neutral by 2050.
Not only is this a huge win for the environment, but also greatly benefits the occupants of these buildings. With the inclusion of rooftop solar, homeowners buying new construction stand to save tens of thousands of dollars in electric bill savings, and in most cases can finance the cost of the solar system on the mortgage of the home.
Frequently Asked Questions About Local Laws 92 + 94
To help builders understand the special requirements needed to site at least 4kW of solar, here are a few examples below. It’s important to note that a 4kW is the minimum system size, but the average solar system size for a single family home in NYC is closer to 7kW on average.
How much square footage is required to install a 4kW solar panel system in NYC?
Depending on the panel type and efficiency, a 4kW system could require between 10 and 14 solar panels.
Using the highest efficiency panels available — a 10-panel solar system using SunPower 400W panels, would require approximately 200 square feet. Doing two rows of 5, a system would be 12.03 x 16.65 ft. Alternatively, a 327W SunPower solar system would need 13 panels to get to 4kW (4.25kW). This would take up 227 sq. square feet. (approx. 15×3 x 17.15 ft.)
How much does a 4kW solar panel system cost in NYC?
The net cost for a 4kW system in NYC could range from $6,000 to $7,000 after solar incentives.
How much money would a 4kW solar panel system in NYC save?
This depends on the pitch and orientation of the building. A southern facing home with a 30-degree pitch would produce 4,500 kWh per year, saving them about $108 per month. This system would pay for itself in approximately 4 years in NYC.
EmPower Solar designers and engineers are standing by to provide support and assistance to any builders, architects, or engineers with questions on this matter. Learn how to design “solar ready” and more about NYC solar mandates here.