New York City (NYC) Mayor Bill De Blasio certainly set the proverbial cat amongst the pigeons on Earth Day last week by publicly declaring: “We are going to introduce legislation to ban the glass and steel skyscrapers that have contributed so much to global warming.” This and other provocative statements certainly made the architectural and glass and glazing community sit up and take notice.
However, on closer investigation, it seems like De Blasio was using exaggeration as an attention getting tactic – one that clearly worked!
The legislation in question would not actually seek to ban highly glazed façades. It would just require them to meet more stringent energy requirements, therefore allowing only high-performance building envelopes. In principal, that seems a very reasonable stance, but of course, the devil is in the details.
But what about existing buildings?
While there has been plenty of discussion of this potential legislation for new buildings, NYC’s newly passed Climate Change Mobilization Act – aimed at improving existing building performance (the majority of buildings) – has largely gone undebated in our industry. This legislation was developed in response to a recent inventory study, which showed that existing buildings accounted for 67% of the city’s greenhouse gas emissions.
This legislation has the potential to be more disruptive to the market by forcing owners to reduce greenhouse gas emissions of their buildings by 40% by 2030. Estimates put the cost of compliance at $4 billion! The real estate community is not happy. Given the aging NYC building stock with single-pane, leaky windows and façades, there is significant potential for full window and curtainwall replacement and providing owners with innovative solutions for historic preservation.
Highly glazed façades can have high energy performance
In the façade community, we know that highly glazed facades can already be designed to meet high energy performance levels. The technology is available and has been for some time. Consider the New York Times Building (now more than ten years old) in NYC, the Tower at PNC Plaza in Pittsburgh, and Genentech’s flagship HTA façade in South San Francisco, which are great examples of high-performance façades in the U.S. In addition, many manufacturers in the U.S. already have commercial R5 fenestration systems commercially available.
These technologies and design strategies just need to be specified and – more critically important – building owners need to be willing to make the higher cost investment.
Using building codes to drive adoption
Many architectural design teams would love the opportunity to construct façades to higher performance, but they are constrained by their client’s budget and the relatively low baseline of the local jurisdiction’s current energy code adoption. And so that’s where more stringent codes come in.
History has demonstrated that – unless forced to do so by codes or through lucrative tax incentives – markets will not widely adopt higher-performing systems where the payback on first costs are longer than three to five years.
Non-mandatory “stretch” codes and standards (like ASHRAE 189.1, LEED and IgCC) can help validate technologies, designs and processes, but baseline mandatory codes are the levers that deliver more widespread adoption and subsequent improvements in cost effectiveness.
While the risks of reducing window area to meet more stringent energy targets are real, the glazing technology is available to mitigate this risk, if the project investment is made.
The opportunity
Both the legislation for existing buildings and that proposed for new buildings in NYC provide a potential opportunity to increase the adoption of high-performance aluminum and insulating glass solutions that are already available and to reduce their delivered cost. These solutions will need to include some, or all, of the following: Aluminum framing systems with wide, complex, thermal breaks; double skin façades; multi-cavity insulating glass, high-performance warm-edge spacers and glass coatings; and dynamic shading or glazing.
Envelope retrofits are a win for both the planet and the population. Occupants sitting next to these façades will enjoy much better thermal and visual comfort, while still enjoying the access to daylight and views, and all the accompanying improvements in productivity and wellness that we know these provide.