Thousands of New York City’s building owners have been dropped into a race to retrofit their structures to comply with a new citywide carbon emissions law. The city is making strides to de-carbonize, or reduce carbon emissions by 40 percent by 2030 and up to 80 percent by the year 2050. Much of the responsibility for the reduction falls squarely on the shoulders of commercial building owners in the city.
As part of Local Law 97, the city’s Climate Mobilization Act, requires large- and medium-sized buildings to reduce carbon emissions or face hefty fines starting in 2024. The fines are designed to increase until the goals are reached. The new law will have significant impact on building owners and may lead to thousands of building retrofits each year. (Learn more about the law and how to comply in retrofit‘s July-August 2019 issue’s “Special Report”.)
It is reported the new law may impact more than 50,000 New York City buildings. The list includes office towers, market rent apartments, condominiums, warehouses and nearly any building over 25,000 gross square feet. These structures will be required to meet their respective annual whole-building carbon limits during each compliance period. The law exempts or reduces the requirements on city-owned buildings, affordable housing units, hospitals, residences and not-for-profit buildings.
As a requirement of the law, building owners must submit an emissions report by May 1, 2025, and by May 1st thereafter. The report must show that it was reviewed and certified by a registered design professional or the filer may face substantial fines. The fines are stated to be $268 per metric ton of carbon emissions that exceed the criteria set in the law. For example, a 50,000-square-foot multifamily residential building emitting 350 metric tons of carbon would be 12.5 metric tons over its 2024-29 limit and pay a fine of $3,350. If it is determined a false report was filed, the filer may face a fine of $500,000.
For several years, the city of New York has been collecting data on its carbon emissions. After analysis, it was determined that buildings are significant contributor to the greenhouse gas buildup in the city. The analysis found that 67 percent of New York City’s carbon emissions comes from its building stock.
Building owners will need to review nearly every aspect of their energy use, including lighting, heating and cooling systems, electric power and areas where their building is emitting energy in the form of heat or air that has been cooled.
Older buildings may face major hurdles because most may have not been updated to today’s energy codes. Just like an open refrigerator door, they let cold air out in the summer and hot air out in the winter, requiring more and more energy to keep indoor temperatures stable.
Some of the steps that building owners may take to reach the finish line may include:
- Assessing HVAC for efficiency, control systems and carbon-intensity.
- Examining lighting systems, determining if more daylighting can be used and installing LED fixtures wherever possible.
- Surveying the interior to determine what factors may contribute to heat buildup, such as hot-water pipes, computer systems, machinery, commercial kitchens and so on.
- Noting the times when the building is most in use and when it is underutilized to come up with an optimum energy-use schedule.
- Obtaining an infrared or thermal image of the building to visually see where heating or cooling is escaping.
To address the last point, many may think of window replacement as a means to control heating or cooling losses. However there a number of other factors to consider before window replacements are factored in:
- The building’s weight and the vertical load that is supported by the foundation can be substantial. Moreover, the building weight increases non-linearly with height; both ultimate bearing capacity and settlement need to be considered carefully. Older buildings may not have been designed to carry the extra weight that new commercial-grade, double- or triple-pane windows add.
- What will the impact of window replacement be on the existing tenants and on the cashflow for the building? The disruption of removing and replacing windows can be a time-consuming process that may take many months.
- Manufacturing glass windows uses significant amounts of energy and the disposal of older windows may only add to the scarcity of landfill space. Disposal also may prove to be a health hazard because older windows may become an environmental hazard during removal or disposal or both.
- The payback period based on energy savings from window replacement may span anywhere from 15 to 40 years according to a 2013 cost benefit analysis conducted by the Building Technologies Office, Department of Energy (DOE) for school buildings.
Window films, whether professionally installed on a building’s interior or exterior may reduce energy consumption by 30 percent, while the installation cost may be 91.5 percent less than putting in new windows, according to the International Window Film Association. In general, the payback period for window film may be less than five years (and could be as few as two or three years).
There are many benefits of having window film installed on a building, especially on a hot summer’s day. In many cases different parts of a building have different needs throughout the day based on where the sun is hitting it. For example a building’s east side may require additional cooling while the building’s west side might require heating. Window film can help serve as an insulator and cooling aid in multiple zones. When there is a peak in demand, like in the summer, many films may reduce solar heat gain by 80 percent.
Consider the following additional benefits for window film:
- Window films are rated, just like glass windows, for performance by the National Fenestration Rating Council (a DOE supported program). An IWFA window film manufacturer can use proprietary software providing a cost-benefit analysis and recommend the optimum specification for window film on a given building.
- Window film cuts the sun’s harmful UV penetration by 99 percent, which reduces fading of furnishings and protects the skin and eyes from its damaging impact.
- Window film can be quickly installed without significant disruption to building occupants.
- Window films can change the look of a building to make it look more modern and uniform in appearance.
- Many window films are warranted for 15 years or more and may also have a manufacturer warranty that extends to the existing glass window.
New York City’s building owners may face a host of decisions as they consider what steps to take in their race to de-carbonize, but window film may prove to be a cost-effective and impactful retrofit in support of the city’s emission reduction program.