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INTERVIEW: NY Passive House President Ken Levenson on the Booming Passiv Haus Movement

Posted By Leonel Ponce On June 15, 2011 @ 10:08 am In Architecture | 1 Comment

ny passive house, passive house, passiv haus, nyph, ken levenson, loading dock 5, interview, green building sustainable building, energy efficiency [1]

We at InhabitatNYC have barely been able to contain our excitement as we’ve followed the progress of various Passive House projects [2] in the tri-state area. In addition to these finished works [3], several projects under construction in and around the city are following Passiv Haus standards, a sustainable building system which originated in Germany and focuses on reducing operating energy and enhancing comfort and air quality within. New York Passive House [4], like other local chapters of the Passiv Haus Society, was created to promote the movement’s standards in the local area by creating an open forum for designer, construction professionals, manufacturers, clients and others. Inhabitat recently had the pleasure of speaking with local architect and NY Passive House co-founder and president, Ken Levenson [5]. Read ahead for the exclusive interview!

INHABITAT NYC: New York City has seen a sudden explosion in construction of Passive House projects over the last year or so. From NYPH’s standpoint, what are the primary goals of Passive House construction, and the Passiv Haus movement in the United States?

Ken Levenson: The goal of Passive House standards is to optimize the construction down to what must be built, to avoid using any construction bells and whistles that aren’t absolutely necessary. By following the standards, participants optimize the building performance, achieving much better interior thermal comfort and air quality, as well as a dramatic reduction in the heating and cooling energy requirement. The heating and cooling energy demand reduction [6] is so great (at 90%) that projects become very cost effective, and have huge cost benefits to the building owner and occupant going forward.

INHABITAT NYC: Passiv Haus has grown exponentially in Germany and all across Europe in recent years, yet it is just now beginning to surface in the United States. What are the main challenges to achieving Passive House standards in NYC and the U.S.?

Ken Levenson: The most complicated issue builders encounter in Passive House construction [7]is the air tightness, and its uncertainty. You can calculate the thermal performance of the building very well with the PHPP (Passiv Haus Planning Package) spreadsheet and software, and you can know whether you’re building to specifications or not, but until you actually hit threshold numbers in the blower-door test [8], you don’t know if the building is actually air tight. And as we’re doing more projects, we’re seeing more details of what works and what doesn’t. It’s a big part of NY Passive House to get the professionals and the people working on projects to share their experiences so we’re not all making original mistakes. We can share our mistakes, teach successful methodologies, give tours of different houses, and see what other people are doing and how their projects succeed.


INHABITAT NYC: Passive House certification requires a diligent, strict following of the guidelines, to achieve specific performance standards, so it’s not a point-based scale such as LEED. How does it compare to other sustainability standards? How is PH advantageous in relation to LEED or in conjunction with LEED?

Ken Levenson: It’s great to use a combination of Passive House and LEED. The strength of PH is that it’s very narrowly focused on the energy requirements and has the counter-intuitive benefit that by focusing very strictly on the energy usage you end up with a building that has a lot of good qualities about air quality and thermal comfort. But Passive House is really about energy, while LEED and other sustainable design certifications [10] can cover a wide range of things from land use to water use to toxicity of materials — Passive House does not address those issues. Certainly the people that are inclined to participate in PH are concerned with overall sustainability, and it goes hand in hand with the goals of Passiv Haus standards, so the less toxic a house, the lower the embodied energy of the construction. These are all good things, but not required for the certification. Passive House is really a nice complement to what LEED has been doing, and it’s not in competition with it.

The main difference, though, is that PH is an absolute standard. There’s no baseline energy modeling, there’s no saying “in comparison” or “this building type.” Pretty much any building type, anywhere has to give an absolute number. It gives the person trying to build to a Passive House real clarity. It’s pretty black and white, in terms of whether you’re making certification or not. And most prospective Passive Houses are not getting certified.

INHABITAT NYC: If you’re a client or a builder of a Passive House project, wouldn’t you think twice about investing in certification if it may not be achieved?

Ken Levenson: The project still benefits from using certified consultants and striving for building certification, for a few different reasons. Principally because once you’re certified, if you know what you’re doing, as long as you’re building to the methodology, getting the air tightness, getting the insulation levels, using the PHPP, the building certification isn’t really giving you a benefit. But for the early projects, I think it’s particularly useful to get certified, and certainly like LEED, when you have developers in projects, they’re looking to the certification as a gold standard [11] to then take to the public and use to sell property.

INHABITAT NYC: I understand that it’s not necessary to create a Passive House certified building to achieve great energy efficiency. But if a client were to want that certification, to renovate a house into a PH, would one need to use one of the architects listed on the website and/or Passive House certified, or could the client bring in the design and construction team of his or her choice?

Ken Levenson: Yes, absolutely. Passive House is open source to a certain extent. You have to use the PHPP software, which is $150, but anyone can use it. It’s a lot easier if the person that’s using it is taking the certified training and gaining those levels of experience. You can use any building components in passive house construction, you can do any type or use of building to passive house standards, it can be any shape, any style. But to make life easier in terms of hitting the passive house standard, it’s easier if you use certified components, it’s easier if the shape is simpler. So you can definitely bring in any design team, but in terms of the website and passive house, there are people listed that are certified consultants, that work with architects, that work with homeowners, and then there are contractors that are certified. The client can bring those pieces together in any number of ways.


INHABITAT NYC: How did you become interested in Passive House construction?

Ken Levenson: I became interested in Passive House because I was looking at low energy lifestyles, all sorts of strategies to lower the carbon footprint of one’s life, and thinking of climate change’s impact on the built environment. I came about Passiv Haus on the internet a few years ago, and it was the first movement that I saw in green building and sustainable design that not only had a huge impact on energy and going beyond net zero [13], but was measurable and was attainable.

The predictability of Passiv Haus really spoke to me. One of the problems with green construction, as most people involved in the field are aware, is the lack of predictability. A lot of “green projects” are turning out to be big energy hogs. These buildings may have very admirable green qualities to them, but in terms of energy they’re a disaster. So Passive House spoke to me in saying, if you do X, Y and Z, you’re going to get THIS result, and it was a revelation. Before that it was difficult to take a full range of sustainability options to a client and say, “You know we really need to invest in these windows and we really need to invest in this and this,” and the client is going to ask, “well, what’s the net result,” and the design team is not sure. The client really has to be altruistic at that point, but with Passive House, altruism isn’t required. It’s a pure transaction, and the designer is saying “if you do this, you’re going to get this, and it’s your decision to make.”

INHABITAT NYC: How did NYPH come about? How does the organization bring together architects, designers, and clients to get projects started?

Ken Levenson: New York Passive House is a local nonprofit founded just under a year ago by Passive House enthusiasts in New York City and in conjunction with what we knew to be happening around the country. The monthly meet up events are organized through the Meetup website (used for all sorts of events and interests), advertised through the NYPH website. We  bring together a pretty diverse crowd of architects, builders, homeowners, manufacturers, students, and people that just heard about it. We’re just getting together a space in New York for people to connect up, and see what happens, to be a catalyst. Every week we get a few more members, more manufacturers, more professionals, more homeowners, and it’s really exciting. There are a lot more projects being planned each month. It’s growing fast.

INHABITAT NYC: How do you personally incorporate Passive House standards into your work at your firm, Ken Levenson Architect?

Ken Levenson: I’ve been very fortunate in that in the last year we’ve been able to have a number of projects with PH standard, so hopefully they will be certified and certifiable, because of lessons learned through shared experiences. In terms of the projects and applying those lessons, we have four projects in construction right now that are potentially going to hit Passive House certification level. We’ll see how it goes. But we’re doing a number of projects that are not going to hit those levels, because we’re just not renovating the house to the extent that’s required. Yet we’re doing what we can to make those houses airtight, and much more rigorously than we would have otherwise. The windows that we are putting in are not going to be PH certified, but they will be triple glazed, much more high performance windows [14] than we would have used normally. We’re putting a high performance ventilation system in the house to get the fresh air up in the house, and trying to make it as airtight as possible. And we’re using PHPP to calculate and try to figure out, maybe not as exactly as we would have for a house that we’re trying to get certification for, how the house will function. So we’re using a non-Passive House project and still implementing Passive House methodology up to a point. Over the next year or two there should be a number of our projects that have different levels of “passive house-ness,” and we’ll see how they perform, and see what’s working and what’s not working.


INHABITAT NYC: How do you foresee the progress of the Passive House movement throughout the country and specifically in New York City, not just in homes, but also in commercial or other types of construction?

Ken Levenson: Passive House is growing, and it’s growing geometrically. If you looked at the Passive House 101 presentation (shown earlier at the event), you saw one quick Passiv Haus project timeline graph that shows a curve going up. And it’s really happening in the US now; we’re starting from zero, so it’s still just a handful of projects, but it’s going fast, and it’s growing across the country. Mostly in the coasts, mostly in New York, California, Washington State, Oregon, Massachusetts, Virginia, but it’s going. It’s going to be big!

+New York Passive House [4]

+475 High Performance Supply [5]

Article printed from Inhabitat New York City: http://inhabitat.com/nyc

URL to article: http://inhabitat.com/nyc/interview-ny-passive-house-president-ken-levenson-on-the-booming-passiv-haus-movement/

URLs in this post:

[1] Image: http://inhabitat.com/nyc/interview-ny-passive-house-president-ken-levenson-on-the-booming-passiv-haus-movement/ny-passive-house-ken-levenson-2/

[2] Passive House projects: http://inhabitat.com/nyc/photos-inside-the-new-williamsburg-passive-house-by-loadingdock5/

[3] finished works: http://inhabitat.com/nyc/hudson-passive-project-becomes-first-certified-passive-house-in-new-york/

[4] New York Passive House: http://nypassivehouse.org/

[5] Ken Levenson: http://www.foursevenfive.com/index.php?main_page=page&id=16

[6] energy demand reduction: http://inhabitat.com/nyc/kiss-cathcarts-the-lee-opens-the-doors-for-green-supportive-housing-in-the-lower-east-side/

[7] Passive House construction : http://inhabitat.com/mut-architecture-unveils-12-wooden-passive-houses-for-parisian-suburb/

[8] blower-door test: http://www.energysavers.gov/your_home/energy_audits/index.cfm/mytopic=11190

[9] Image: http://inhabitat.com/nyc/interview-ny-passive-house-president-ken-levenson-on-the-booming-passiv-haus-movement/ny-passive-house-thermogram/

[10] sustainable design certifications: http://inhabitat.com/inhabitat-interview-green-architect-cradle-to-cradle-founder-william-mcdonough/

[11] gold standard: http://inhabitat.com/nyc/nyc-historic-argonaut-building-achieves-leed-gold-after-green-renovation/

[12] Image: http://inhabitat.com/nyc/interview-ny-passive-house-president-ken-levenson-on-the-booming-passiv-haus-movement/ny-passive-house-brooklyn-cohousing/

[13] going beyond net zero: http://inhabitat.com/nyc/nyc%E2%80%99s-first-zero-energy-school-p-s-62-in-staten-island-designed-by-som/

[14] high performance windows: http://inhabitat.com/how-to-green-your-home-with-windows-from-marvin-windows-expert-christine-marvin/

[15] Image: http://inhabitat.com/nyc/interview-ny-passive-house-president-ken-levenson-on-the-booming-passiv-haus-movement/new-york-passive-house-ph-timeline-a/

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