You might have heard wild-eyed sounding rumors in the past about the European Union legislating net zero buildings. Those weren’t rumors.

A few years ago, the EU parliament required all new buildings to be “nearly net zero” (being defined by each state) starting in 2019. Existing ones that undergo major renovations will have to hit energy performance targets set by the member states. In the UK, new homes need to hit that target even sooner – they need to be carbon neutral by 2016.

Now California (any surprise?) has established a net zero beachhead in North America. Under an executive order issued by Governor Brown on April 25^th, by 2020 half of new State buildings and major renovations will be net zero and all by 2025.

If you’re wondering how they are going to design these buildings, one could look to the net zero projects on the drawing boards in New York City: P.S. 62 on Staten Island (starting this year), Solar 2, and Cornell’s Roosevelt Island campus. And if they can do it, perhaps it’s time that we follow California and the EU’s lead?

That would be a bad idea. The first part of net zero – extraordinary load reduction – is something that all new buildings could and should achieve. We’re seeing it with these projects and we’re seeing it with Passive House. But the second part – generating solar electricity onsite – just isn’t possible for many buildings in New York. It’s no coincidence that all three New York net zero projects have large roof to square footage ratios, and are also in open areas of the city without neighboring buildings to shade their roofs.  A high-rise just doesn’t have enough roof area for PVs to generate its own energy and the only way they could meet a net zero mandate would be to purchase expensive renewable energy credits. According to our research director, Richard Leigh, “for almost any commercial or residential use, even with efficient lighting and appliances, the solar resource to get above three stories and meet net loads with on-site collectors just isn’t there, even out in the open countryside.”

So let’s build super energy-efficient buildings and install whatever onsite renewables we can. But as we look towards the next generation of green buildings, let’s remember that while net zero can be done for low-rises it doesn’t work for high-rises.

Passive House at 174 Grand Street, Brooklyn, NY; credit: Loadingdock5

What mixture of building systems will deliver a truly “sustainable” high rise? We’re not aware of anyone who knows the answer yet (if you do, please call). And if we don’t know where we are ultimately aiming, we may not be making the right investments now. For instance, we worry about how in the last ten years the energy performance of mechanical systems has improved while that of envelopes has generally declined (see NYC Green Codes Task Force recommendation EF3 Limit Heat Loss Through Exterior Walls).

In contrast, we are in far better shape when it comes to low-rise construction, thanks to Passive House. The standard has proven that we can achieve enormous energy reductions in homes through a combination of a well-insulated and air-sealed envelope, heat recovery ventilation, and smart use of the sun. Compared with conventional U.S. homes, Passive House is thought to reduce energy for heating and cooling by 90% and overall usage by 75%; for Energy Star, it’s a 30% overall energy reduction. This is why we wholeheartedly embrace the Passive House standard and see it as a lighthouse for where small-scale construction needs to go.

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Right, Passive House.  Left, not Passive House.  Enough said?

We hope you can join us on April 6th for a presentation and discussion of the principles of the Passive House standard.

Years of hard work by folks like Katrin Klingenberg at the Passive House Institute US (PHIUS) are beginning to pay big dividends as interest in the German standard rises every day across the country.  While PHIUS handles certification of projects in the US, the Passive House Alliance has been created to advance education and outreach efforts nationally, and to support the efforts of local chapters such as our very own NY Passive House group.  This formidable local group is organizing monthly meetings and tours of local Passive House projects.  On April 6th we are lucky to have two of the real forces behind NYPH presenting the principles and methodology of the standard; Ken Levenson and Floris Buisman.

Even if you are not considering Passive House certification for your project the basic principles of the standard are sound for any building because learning about Passive House is also learning about the fundamentals of low energy design.  Every architect or engineer that learns even the most basic elements of Passive House is a small victory against the forces of darkness.

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Loading Dock 5

Lloyd Alter at Treehugger offers up this excellent photograph of a passive house project in ultra-hip Williamsburg, Brooklyn showing, rather elegantly, how little heat escapes from the house compared to the adjacent structures (red is heat in the photo.)  Mr. Alter asks the salient question: Why would anyone build “any other way any more?”

The New York Passive House group has arranged a tour of the Grand Street project on January 18th.  If you think you are cool enough to walk those sidewalks I recommend you attend.  Click here for the NYPH website, then click on events for their calendar. They have some more details about the house here.

An elegantly simple introduction to the Passive House standard on the GreenSpec site.

Tom Zeller Jr. has a great piece in the Times on the introduction of the Passive House standard in the United States.  It’s a carefully researched summary of the challenges facing broad adoption of this important standard and well worth your time even if you are familiar with the issues at hand.  It really is a strong piece.  Zeller has done his homework, addresses the issues head on, does so in language lay people can follow without dumbing down the content much, and avoids the snarky “Gee-this-green-stuff-is-just-so-hard” tone that pervades so many pieces on green building in the major media.

It just so happens that our annual conference this week, Urban Green Expo, features a panel on just this subject.  It’s called “The Active State of Passive House” and includes Tomas O’Leary, Founder of the Irish Passive House Academy, who has traveled here specifically for the conference and will outline the lessons he’s learned over 15+ years of implementing the Passive House standard in Ireland.  The panel also features local luminaries in the Passive House community, architect Ken Levenson and engineer David White, as well as Brian Philips, the Philadelphia architect responsible for the “100k” house.  I hope you’ll be there.

Continuing on our recent European theme- I’ll point you to a couple articles on high performance windows from across the pond.  The first focuses on triple glazed windows, and the second on Passive House certified windows.  It’s amazing to see the difference in technology and quality of the units available from places like Germany and Sweden- most of which are triple glazed.  It’s a shame that our codes don’t require these type of windows but it’s even more of a shame how difficult it is to source them even if you want to take the plunge.  This is one of the issues we hope to address at our conference, Urban Green Expo 2010, the theme of which is Pushing the Envelope.

All the cool kids are talking about Passive House these days.  In a futile attempt to ingratiate myself with the ‘in’ crowd I’ll point all of you to this fantastic and unbelievably thorough overview of Passive House by Alex Wilson at buildinggreen.com.  Even the Daily News got in on the act last year with an article focusing on the low-tech, cost-effective aspects of the German standard.

I hope to develop some educational programs on Passive House later this year.  It has enormous potential to transform the way we think about energy use in buildings- focusing on an energy conserving envelope and airtightness, rather than expensive technologies or incentive-dependent renewables.  If you have an interest in Passive House there is a NYC meetup group that you can join here.  Jeremy Shannon, the organizer of the meetup, has his own blog on retrofitting a Brooklyn rowhouse to the Passive House standard.

Lloyd Alter at Treehugger writes on this under-construction Passivhaus project in California. Most Passivhaus projects have been in northern climates and have gone to great lengths to minimize square footage and exterior surface area (leading to squat though not always inelegant boxes.) This CA house aims to show the standard can be achieved with a more conventional (by American standards) sized home in a courtyard configuration. We’ll be following this project as it develops.