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Nancy Anderson, Ph.D.Torchlight

Getting Active On Passive House

By: Nancy Anderson, Ph.D.

June 18, 2015

I'm a fan of Passive House. Ever since visiting the top-to-bottom renovation job for an elegant 19th century home in Brooklyn Heights undertaken by architect Ken Levenson back in 2011, the potential for constructing — or in this case reconstructing — urban buildings to keep occupants really comfortable year round without boiler heating or air conditioning in every room has been my yard stick to measure all other climate-friendly buildings. Levenson's Snapshot column was the first introduction Sallan readers had to Passive House, and since then, Ken's been one very busy Passive House advocate.

Still, he wasn't the first to use lots of wall and roof insulation in new ways, install super energy efficient windows and deploy other techniques to make energy efficiency and indoor air quality top priorities in NYC residential buildings.[1] Chris Benedict, using an approach similar to that of Passive House, seems to be the first architect to execute extraordinarily energy efficient design for both new construction and gut renovations in the City, with an emphasis on affordable housing. She also makes the claim that radically energy efficient building design opens the door for a drastically simpler building energy code, which means much less time and effort on the part of owners and architects when applying for permits. And that's not all. In June 2015, at the fourth annual New York Passive House (NYPH) conference, Benedict and her partner Henry Gifford received the NY Passive House Pioneer Award from Levenson. Earlier this year, Sallan introduced readers to the Passive Net Zero Energy condo in Prospect Heights Brooklyn undertaken by architect Paul Castrucci and Green Map maven Wendy Brawer. Cheers to all!

This brief history serves as a lead up to my take-aways from this year's NYPH conference. Let's start with the numbers. They're small. At present, there are 28 Passive House projects in New York City. But the actual number of PH residential units here is about to surge. At the conference, Related Companies announced a residential high-rise project for the now-under-construction Cornell University applied sciences campus on Roosevelt Island. Described by the New York Times as the "world's tallest passive house", it will be a 26 story, 352 housing unit building on a campus with aspirations to being net-zero carbon in its operations. The Related spokesman Luke Falk said this residential tower will use just 25% of the energy of comparable new buildings, but unlike Passive House projects in northern European cities, air conditioning will be installed to cope with New York's notorious hot and muggy summer weather. Unlike Benedict's mid-size multi-family buildings, the large Cornell tower will have central ventilation and heat recovery systems. Determining how to get Passive House-performing ventilation systems to comply with New York City building code has been one of the learning curves in this project. The good news is that it can be done and this will make doing the next passive high rise and the one after that easier. This is certainly an encouraging take-away.

My other chief NYPH conference take-away, however, was that today's market demand for a Passive House is not robust here. At the "Developer Roundtable: Views From the Leading Edge of Market Rate and Affordable Housing", moderated by Stuart Brodsky, participants spoke frankly and in-depth about their experiences in New York City, Philadelphia and London. The Philadelphia-based Passive House architect and developer left me with the impression that the City of Brotherly Love was way out ahead of the Big Apple when it came to scaling up the number of new affordable housing projects that meet Passive House standards. Such leadership rests on the state's housing finance agency scoring system which gives extra points to Passive House designed project applications, but does not require projects to be Passive House compliant. The speaker, Timothy McDonald, stressed that this was a Passive House victory, but one not achieved through policy-making by mandate.

A London-based developer of renovated market-rate housing whose energy efficiency is way above the norm focused on his firm's market research. Here's where things got interesting. The research found that home-buyers were willing to pay more for good soundproofing, but not more for energy efficiency. Since the building envelope insulation that soundproofs a structure also makes it much more energy efficient, his marketing message emphasized the former along with the 'healthfulness' and thermal comfort of these properties. A Brooklyn developer describing new market rate condos designed to be an "energy intelligent building" ruefully conceded that Passive House standards were "not what closed the sale". Instead, for developers like him, however personally committed to cutting his carbon footprint, a more direct incentive to build green is found in recent zoning changes, which grant developers more floor area to build when they use more building envelope insulation than required by code. On the other hand, as was noted, "appraisers are god". Since Passive House up-front costs don't compute for them, appraisals act as an obstacle to energy-active projects.

NYPH 2015 was the fourth annual conference I've attended. Each year more people come, each year, the speakers have more projects to describe and more facts on the ground to report. These appear to be upbeat trends to a fan like me. It's heartening to hear that US cities like New York and Philadelphia are getting more Passive Houses. Experience counts. As well, forces to be reckoned with by every developer, like building and energy codes, zoning requirements and project financing criteria all play a role in shaping the adoption of super energy efficient building design — even if market demand does not lead the way — are trending in the right direction. Still, it does seem that Passive House has a long way to go before it becomes a contender for the title of the new normal in US cities. What will move the needle? In One City Built To Last, the de Blasio administration puts Passive House on its roadmap for shrinking the City's carbon footprint when it "Implement(s) leading edge performance standards for new construction." As well, the report One New York: The Plan For a Strong And Just City cites, "The first net-zero school is currently under construction in Staten Island by School Construction Authority. DCAS is exploring additional public buildings to serve as additional net-zero or Passive House pilot projects." Maybe at NYPH 2016 we'll be nearing the tipping point for getting active on Passive House.

[1] At its simplest, Passive House can be thought of as a set of cooking instructions rather than collection of prescriptive codes. It's outcome oriented. By combining the basic ingredients — a highly insulated building envelope with few thermal breaks — the result is a building with high thermal performance. Installation of a continuous ventilation system that runs on recovered heat ensures good indoor air quality, occupant comfort and low energy use. A building's EUI rating is the outcome-oriented standard measure of energy performance. For a more in-depth description and links to resources and project descriptions see NYPH

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