“To a certain extent, the results of this study are obvious. If all you have to protect you from the elements is the building envelope, of course a better envelope will protect you more than a poor envelope. What’s startling is the huge difference between what existing buildings provide and what a high performance building is capable of.” - Nico Kienzl
It’s not just science fiction.
Nico Kienzl (Atelier Ten) got a chuckle from a full house at this special event with a computer-generated image of a frozen New York from The Day After Tomorrow. But it’s not just science fiction – his computer models used in Urban Green’s report Baby It’s Cold Inside show how the “massive holes” in the walls of NYC homes will put residents at risk if the next power outage comes during severe weather.
Developers like Paul Freitag (Rose Development) are responding by putting up safer buildings that incorporate both green and active design elements. Via Verde uses cross ventilation to reduce the need for air conditioning, cutting energy bills for residents and helping prevent overheating during a summer power outage. The community’s daylit, bright, colorful stairwells encourage everyday use, enhancing residents’ health – and are also usable when the power for stairwell lighting fails.
After hearing Via Verde’s virtues, moderator Bomee Jung (Enterprise Community Partners) asked:
Who doesn’t want to go hug Via Verde right now…but what about all of our old buildings in New York?
The most important improvement in existing buildings is to reduce infiltration, said Nico. “We’re talking about massive holes, not cracks.” High air change rates mean major heat loss, so closing holes makes a big impact and does not cost a lot of money. Increased resiliency doesn’t have to mean expensive window replacement – good news for NYC’s massive number of single-family homes. Basic weatherization does make a difference.
Romulus Petre (Urban Glass House) pointed out that we can’t count on multiple days’ evacuation notice before every power outage. So with all the competing demands to improve building resiliency – floodproofing, raising equipment, adding backup generators – where do improved envelopes fall in the priority list?
Nico thought the emphasis on a strong envelope was key. To prevent widespread evacuation during a blackout, buildings need to provide heat and cooling in some way, either by relying on complex mechanical systems or by having a better envelope that can maintain indoor temperatures. The latter has two advantages: it saves energy all the time, so there is a much better payback because benefits accrue dependably over a long-term period, not just during emergencies. And, better insulation and air sealing keep expensive conditioned air from leaking out of the building. That means the building saves space and money, since it requires smaller generators and fuel tanks. Nico commented that “during the Building Resiliency Task Force, we discovered that some issues are purely about emergency management. But some have clear crossover into operational efficiency, and the façade is one of them.”
Speaking of operational issues, Romulus said as a superintendent he’s at the “lowest end of the food chain,” keeping people safe no matter what. He agreed with Nico:
I would give everything to have a better envelope.
He would prefer a better envelope to better mechanical equipment, both for resident energy savings and for ensuring resiliency. “You can play around with the equipment over time, but an envelope is built-in and saves you in an emergency. As a super you deal with what’s given to you, and I would love a better envelope.”
So if designers, developers and operators agree that improved envelopes are a no-brainer, what can the city do to help them become the new normal? Heather Roiter Damiano (NYC Office of Emergency Management) believes the city’s approach to emergency management may grow to include this issue over time. Within the OEM hazard mitigation unit, “the focus has moved from response, to preparedness, and now to mitigation and recovery. The code changes after Sandy are driving awareness of the nuance” of building resiliency. Perhaps in the future, OEM will take a similar role fostering and improving building resiliency codes as FDNY has taken with the Fire Code.
The code changes Heather refers to will aid resiliency. And Paul is working on innovative design solutions like community centers that double as “resiliency centers” during a crisis. But Nico pointed out a fundamental flaw built into the construction process. While complying with the energy code during design, buildings can escape envelope requirements by substituting better mechanical equipment. It’s a tradeoff of HVAC against insulation, but as Nico said: “that tradeoff doesn’t work when you have no power.” He left the audience pondering a hard question: “Should we start thinking more rigorously about building envelope tradeoffs, so we have a safe blanket when it gets cold outside?” Let’s not wait until the next disaster to answer.