November was a busy month for façade geeks, especially those on the East Coast. The Façade Tectonics Institute‘s (FTI) Forum event in New York City, hosted by the Ornamental Metals Institute of New York, happened at the beginning of the month and was preceded by an evening of food, drink and façade education hosted by Schüco. Topics at these events focused on the impact of newly enacted Local Law 97 in New York City, and the question: Are all glass buildings a thing of the past?
At the Schüco event, I had the pleasure of moderating a panel of four experts – Steve Selkowitz, senior advisor at Lawrence Berkeley National Laboratory (LBNL); Hale Everetts from innovative real estate company, Two Trees Management; Max Wolf associate from Skidmore, Owings & Merrill (SOM) and contributor to the development of Local Law 97; and Anas Kassas, CEO of Inovues, developer of a cost effective window retrofit system. Together, we took a deep dive into the impact of Local Law 97 and what the implications are for envelope retrofits.
Local Law 97 – In Brief
Local Law 97 requires that existing buildings in New York City meet maximum carbon emissions targets starting in 2024. The law is focused on limiting operational emissions – carbon that is emitted through the operation of the building, such as gas burned for heating and electricity for lighting, plug loads etc. The amount of allowable emissions is set as a function of building type (building use group), for example, healthcare, residential or commercial office buildings; and on an area basis (per square foot of floor area). A coefficient for greenhouse gas emissions is assigned to various fuel types, such as electric, gas or fuel oil, to provide equivalence between the energy sources and to account for the fact that some fuel sources are more polluting than others.
Energy use reporting is required by January 1, 2025 for the prior year, and then every year thereafter. The targets become significantly more stringent in 2030. Fines will be assessed to those buildings that exceed the carbon emissions targets (for their use type) and will typically be in the range of $268 per ton of carbon dioxide equivalent emissions above the target level. The law applies to buildings with a floor area of 25,000 square feet and larger, but there are a wide range of exemptions, including rent-controlled residential properties and landmarked buildings. According to Max Wolf, this means that there are only approximately 23,000 of 1 million total buildings (~2%) affected, and if the city’s 80% reduction by 2050 goal is to be met, the scope will need to be expanded pretty quickly.
A New Design Driver?
While it appears that around 80% of buildings should be able to meet the targets in 2024, meeting the 2030 targets will be more difficult, and will require more than just lighting retrofits. One piece of information in the ensuing discussion that excited me was that although Local Law 97 is for existing buildings, it is starting to positively influence decisions made in new building design and construction.
Because new buildings become existing buildings immediately once the certificate of occupancy is issued, buildings currently in the design process will be the subject of Local Law 97 as soon as they are operating and therefore must comply with its targets starting in 2024. If they are not designed to comply when built, costly upgrades will be needed in less than 10 years, driving design teams to target Local Law 97’s 2030 performance levels to “future-proof” their creations. This means that these teams are less likely to skimp on façade performance, because it can be such a significant contributor to the performance of buildings.
What About the All-Glass Building?
During the FTI Forum event the following day, we explored the challenges of designing new buildings and, because of the tightening energy standards, whether all glass buildings are a thing of the past.
- Areta Pawlynsky, principal at Heintges Consulting Architects & Engineers presented examples of high-performance façades spanning a range of window areas: from the highly glazed, double skin curtainwall of The Tower at PNC Plaza in Pittsburgh designed by Gensler, to the limestone cladding system with high-performance, thermally broken punched opening windows of 220 Central Park South, the New York residential skyscraper designed by Robert A.M. Stern Architects.
- Gabrielle Brainard, from Rensselaer Polytechnic Institute made the case for opacity. She made the case that curtainwalls have become ubiquitous primarily because, through easy unitization, they are fast and inexpensive to construct, yet the spandrel areas remain a weak link thermally. She presented the use of unitized architectural pre-cast concrete systems and “mega” metal panel systems in combination with punched opening windows as a way of addressing the installation issues with non-curtainwall-based façades.
- Steve Selkowitz then reviewed a range of commercially available glazing technologies and asserted that an all glass building can be designed to beat the energy performance of a building with opaque walls, but to do so requires an appropriate amount of design effort and financial investment.
I asked this question to both panels: Do we need new technologies to meet these new energy requirements? It turns out that they think we already have the technology – curtainwall and windows with wide thermal breaks, triple glazing, warm-edge spacers, continuous insulation techniques, solar shading technologies – we just need to budget for, and to specify, high-performance systems in designs. This seems like an upfront investment with an effective return when considering the penalties associated with Local Law 97.
Thanks for this fine summary of these excellent events, Helen. I support Local Law 97 and other similar “stick” type initiatives, but wonder if the “carrot” might even be more effective, especially in combination. Profitability is driving the ongoing negative impact of buildings and urban habitat. If we could find a way to link profitability with sustainable performance outcomes things would change fast, but this would require massive long-term investment in the built environment that we as a society don’t appear to be prepared to make. We don’t seem able to manifest an urgency to deal with our contribution to the climate catastrophe that stands in equal measure to the threat we are building, a threat to the environment and life on this planet. We must develop more effective strategies to accelerate change in the practice of building. It is urgent.