While the passive house concept is taking off in Europe, where over 10,000 passive houses have been built, there are still very few in the States. I have posted before about [intlink id=”393″ type=”post” target=”_blank”]Nabih Taleb’s passive house remodel[/intlink] in Berkeley, and I’ve heard about a few more which I’ll be posting soon. But this month the Taunton Press’s Green Building Advisor website is featuring an article on America’s first “passive house.”
Built by Katrin Klingenberg, a European-trained architect who is co-director of the Passive House Institute U.S., the house uses massive amounts of insulation – including 14″ inches below the slab, as well as up to 16″ in the walls. Klingenberg also took care to site the house for maximum solar gain in the winter, as well as many other details to increase the house’s energy efficiency.
The results have been excellent – although not without some learning opportunities. Those windows that allowed the sun’s heat to warm the house in the winter overheated it in summer. Klingenberg installed a grape arbor over the windows, and now its bare branches in winter let in the sun, and its leafs provide effective shading for the windows in summer, while also giving a beatiful view.
Klingenberg was not just after efficiency, but also affordability in this house. And the results on both sides were very good:
At $94 per square foot, the house topped the highest averages for new construction in the region, although not by much. With Katrin’s modest budget and her goal of using the home as a model for affordable housing, however, the cost was more than she would have liked. But she points out that this was a prototype that would likely cost less on a production scale. Besides, in her opinion, the successes in the area of sustainability, efficiency, and comfort were well worth the investment.
The NAIOP, also known as the Commercial Real Estate Development Association, released a report last week “showing” that building green is not a winner in terms of payback. Apparently timed to coincide with a Senate Energy and Natural Resources Committee hearing on improving building energy code standards, the report found, according to a New York Times/ClimateWire article, that:
A 50 percent energy improvement beyond federal standards is technically impossible. A 30 percent target is achievable, but only by adding a million-dollar solar system that could take up to 100 years to pay for itself
In the same article, several energy efficiency experts raised questions:
Jeffrey Harris, a vice president at the pro-efficiency group Alliance to Save Energy, said these claims have a sturdy foundation in laboratories and in the real world. He pointed to the Energy Department’s data on high-performance buildings, as well as other databases containing information on existing buildings. Engineers and green-building leaders, he said, “are not breaking a huge amount of sweat in getting beyond 30 percent in code.”
Throughout the green building blogosphere numerous rebuttals started flying. On the news site for Costar, a commercial real estate information site, Andrew Burr wrote:
The study overlooked a number of highly cost-effective energy efficiency measures that are common in new buildings, such as light occupancy sensors and louvers that affect shading and heat gain, several people in the industry said, while integrated design strategies were not implemented in the models at all.
In what is currently the world’s largest LEED Platinum building, the Center for Health and Healing in Portland, Oregon, engineers and architects were able to find savings measures that led to a 60% decrease in energy costs while spending 10% less overall money; this is not some computer-based study, it’s a realized project that was occupied in 2006.
In other words, NAIOP intentionally kept out of the analysis all the readily available low-cost, no-cost and cost-saving options to reduce a building’s energy consumption. This deliberate omission is glaringly apparent in their press release and in the NY Times article. In fact, they take so many inexpensive, energy-saving options off the table that it is impossible for the imaginary building to reach commonly achievable energy-consumption-reduction targets.
In one regard, you could say the NAIOP’s conclusions, when interpreted narrowly, are meaningful – if you build an energy hog building without considering the site, without performing integrated design, and using simplistic efficiency measures, you’re not going to get a good payback. What’s amazing about this, though, is that there are so many real-world counterexamples to the claims this report makes. It’s surprising NAIOP was willing to go public with it. And you have to ask “Why?” – in what way is this report in the long-term interest of NAIOP? Given the Federal, state and local juggernaut of energy efficiency regulations, isn’t it in their interest to figure out how to achieve on a mass scale what individual builders are achieving on a smaller scale? That’s the approach that keeps their constituents competitive, that creates jobs, and creates wealth.
Just about two weeks ago, my friend Matt Harris, an architect with a green building practice, sent me an email:
The City of Menlo Park has this Climate Action plan and they are looking for community input. Would you be interested in formulating some kind of response that would of course include our plug for passive house initiatives. Maybe we can get them to include some passive home or even passive building information or plans or guidelines in the Climate action plan. They have already cited “commercial buildings” as a target energy hog in the city for action in the action plan.
So we’ve been working on this. We got together last weekend to come up with a strategy, then Matt wrote the first draft while I was in Finland last week. I did some editing this weekend, and now he’s got it again.
I wanted to share some of the information I discovered while researching our recommendations for the plan.
Here’s the first set – an annotated list of sites from which I got a lot of great information and inspiration both for this project as well as my high-level goal of having all homes built in California be zero-net energy by 2018.
Aggressive Home Efficiency
Architecture 2030 – The Architecture 2030 challenge includes the following goal for 2010: “All new buildings, developments and major renovations shall be designed to meet a fossil fuel, GHG-emitting, energy consumption performance standard of 50% of the regional (or country) average for that building type.”
Passive House Institute (Germany) – Already familiar to regular readers, the Passive House Institute, Darmstadt, Germany, a research institute dedicated to residential energy efficiency and systems, has shown that actual built structures can achieve 80-90% heating and cooling energy reduction based on their design guidelines. Over 9,000 “passive house” structures, including single family, multi-family, and apartment buildings, have been built in Europe that perform at or near energy goal
Many green building standards have set zero (or near zero) net energy use for residential buildings as a progressive goal for structures and building codes in the near future, including the Leadership in Environmental and Energy-Efficient Design (LEED) standard’s residential rating system, Architecture 2030, and Build It Green’s GreenPoint Rated Checklist residential rating system / Green Building Guidelines for New Home Construction. Several California municipalities have adopted local building codes inspired by Architecture 2030 that exceed the 2005 California Building Energy Efficiency Standards:
I’ll keep you updated on our progress on getting these changes into the Menlo Park Climate Action Plan. It’s exciting to consider that Menlo Park could be on the forefront of the effort to get to zero net energy in ten years!
In honor of this blog’s six month anniversary, I’m going to relink to some of my favorite posts from the past:
[intlink id=”5″ type=”post”]My first post, on fuel cell and battery innovations[/intlink]
[intlink id=”119″ type=”post”]Why I am optimistic about our energy and climate future[/intlink]
[intlink id=”126″ type=”post”]Some reasons my optimism is tempered (a follow up to the post above)[/intlink]
[intlink id=”329″ type=”post”]My predictions for 2018 (ten years in the future)[/intlink]
Also, as regular readers know, I’ve been presenting a series of posts on zero net energy homes. I’ve recently added a new plug-in for the blog that makes it easy for you to find these series, and I’ve put the link to the series over on the right hand column (and right here).
Last night BuildItGreen’s South Bay Professional Guild hosted Nabih Tahan, a Berkeley-based architect who was recently featured in a New York Times article on passive houses. Nabih discussed the passive house concept and how it is being applied in Germany and the rest of Europe, as well as his experience building Low Energy Houses (Niedrigenergiehaus – the generation of homes before the passive houses) in Austria and remodeling his conventional house in the Berkeley flatlands into a passive house.
The term “passive house” reflects the concept that these houses do not have heaters to provide warmth. Instead, they “passively” recover heat from all the other activities in the home – such as cooking, lighting, and even human activity. To enable this, a passive house is highly insulated, with an airtight building envelope, so that no heat can escape. To keep the air quality high, passive houses use “heat recovery ventilators” or “energy recovery ventilators” with air-to-air heat exchangers to constantly replace the old inside air with new outside air, while keeping the heat from the old air inside.
Passive houses typically use about 80% less energy for heating and cooling than conventionally-built houses.
Tahan’s talk covered a huge amount of ground. Some of the high points included:
A description, with a number of photos and a video, of the current German and Austrian technologies for building houses and multi-family residences. These homes are built in factories, by automated, computer-controlled machines, and assembled in a few days on site. Because all the pieces are designed to high tolerances, the building sites are very quiet – if you hear a power saw on one of these sites, you know someone made a mistake.
He showed a picture of “model home mall” in Austria (here’s something similar in Germany – in German), where more than 40 of these pre-built home builders have built 80 model homes that you can tour. The homes range in size and style from modest single family houses to large mini-mansions, to apartment buildings.
I asked what one change in the U.S. would make it easier to build passive houses here. He said better windows and doors. Insulated and well-sealed windows and doors, often with triple-glazing and special coatings on the glass, comprise a key component of passive houses in terms of keeping the building envelope airtight. There are many manufacturers of these components in Germany and the rest of Europe, but none to very few in the States. In fact, Tahan is currently in discussions with investors on starting a factory to build these components, in partnership with an Austrian company.
For his Berkeley house, he decided to work with a U.S. supplier, Sierra Pacific, to demonstrate that the passive house standard is possible in the California climate with local products. In any case, buying the windows in Austria would have cost less than buying them here, but the cost of shipping would have made the Austrian windows more expensive.
In building a passive house, airtightness is as important as the insulation – they work hand in hand. And it’s the most difficult part, especially in the United States where buildings are not constructed by computer-controlled machines.
In Europe, building a passive house costs 4-5% more than conventional construction, but it saves 80% of the energy. Currently it’s a somewhat bigger premium to build a passive house in the States, due to lack of suppliers and know-how.
The passive house concept and approach is clearly a component of a zero-net energy home program. Reducing the amount of energy a home uses means it’s a lot easier and cheaper to generate that energy onsite. Architects like Tahan will be a key enabler of getting to the [intlink id=”329″ type=”post”]2018 goal of 100% zero net energy homes in California[/intlink].
This was an excellent talk, and I’m looking forward to hearing more from Nabih Tahan, and attending more BuildItGreen functions. If they’re all at this level, they’ll be a great resource for getting California to the goal of 100% zero net energy new houses by 2018.
Update (2/13/09): Nabih tells me that the Passive House California Group has just set up their website, where you can read about their next group meeting and other topics.
There’s a perception that green is more expensive and less convenient, and, truth to say, that’s sometimes true. It is more expensive to buy your groceries at Whole Foods. And putting solar panels on your roof doesn’t really save you money for many years, if at all, (although it’s still less than buying a new car).
But on the other hand, we know that there are lots of green things you can do that actually save money – replacing your incandescent lights with compact fluorescents is one familiar example. And if you’re building a house, putting in lots more insulation than is required by code can save a huge amount of both money and energy, while making your home more comfortable.
Sometimes it’s small changes that can flip this perception. I have a recent example from my own life that brought this home to me (so to speak):
My green building and blogging colleague Barry Katz just had a post about James Howard Kunstler on his The Future Is Green Blog. Kunstler is one of the “dystopians” featured in a New Yorker article last week. Kunstler is not sanguine about what the future is going to look like for us and our descendants. He thinks that not only is global warming likely to cause a disaster, but so is the current, or an upcoming, financial meltdown. Barry writes:
In his view, anything short of ending our dependence on cars for personal transportation is a doomed enterprise.
I’ve been skeptical of the “stimulus” as sketched out so far, aimed at refurbishing the infrastructure of Happy Motoring. To me, this is the epitome of a campaign to sustain the unsustainable — since car-dependency is absolutely the last thing we need to shore up and promote.
Could the terrible things he predicts happen? In the New Yorker interview he provides as an example and a warning the famous fall of the Roman Empire – the city of Rome itself went from a population of over one million in 100 AD to less than 50,000 in a little over 400 years. And there certainly have been many other similar collapses in history – even in pre-Columbian North America there were multiple population collapses due to resource overuse (and genocide, but that’s another topic).
The difference today – at least we hope – is that we have some Cassandras – Al Gore, Kunstler, the IPCC, me and Barry Katz, among many others – warning us, and we have the means and opportunity to take the warning. The question is, do we have the will to put the pedal to the metal to address the problems? For me, I see that as doing the following, and doing it much faster than anyone is actually predicting is possible today:
Immediately stop wasting energy – this means getting our houses and commercial buildings more efficient, both new and existing ones; getting more efficient cars on the road
Build out utility scale renewable energy as fast as humanly possible
Develop and commercialize technologies for distributed energy generation (e.g., photovoltaic roof panels and paint, mini-wind turbines, ground source heat pumps) and get them cheap enough to deploy everywhere
Develop and commercialize technologies for distributed energy storage – effective energy storage is one of the key sticking points for my vision of zero net energy homes and for accelerating the decline of traditional power plants
Figure out a way, or several ways, to get some of the CO2 back out of the atmosphere – reforestation is a start (and can make a significant difference, according to this study)
Finally, make structural changes to the rules and incentives of life so people will work closer to where they live, will be able to take public transit in a reasonable way, choose to build highly efficient homes not because its the right thing to do, but because it’s the law, or there are other concrete benefits, and so that businesses will find it’s profitable to save the world – whether it’s through being more efficient themselves, or by helping the rest of us “do the right thing”
I call this blog “Keeping The Lights On” because I am optimistic that we’ll figure out how to have a decent life without CO2, that we’ll figure out how to keep the oceans from rising too much and losing too many species, and that civilization won’t collapse due to a financial crisis in the meantime. There are a lot of hurdles to be leapt to accomplish this, and many of them will be costly – but that means that someone’s going to make some money on them, so there will be incentives. And that’s the other half of the title – “Profitable Applications” – business can drive this transition, for profit. The big challenge is getting business ramped up fast enough to save our butts – I think it can happen, and even with the economy in its current sad state, we’re still seeing hopeful signs.
Well, that’s a couple of pages full of assertion and conjecture – I’d love to hear your thinking on this.
The Cannon Beach house, built by Nathan Good, architect, and Rich Elstrom Construction. I saw this house first in Fine Homebuilding special edition on green housing. Fine Homebuilding, and the Taunton site in general, has a huge amount of information on green building.
This is the first post in a series on zero-net energy homes. Over the course of the series I will be covering all aspects of this topic, from the technology and knowledge available today, to the changes needed in technology, building codes, trade skills, design approaches, and will to achieve the goal of all new homes eventually being zero net energy.
Definitions and feasibility
What is a “zero-net energy home?” Zero net energy homes generate as much energy as they use. Energy used = Energy Generated. The experience of thousands of “off the grid” home owners and those bleeding edge homeowners with big solar panel installations on their roofs show that zero-net energy homes are technically feasible today. For example, see this article on Amory Lovins’ home and office in Snowmass, CO.
We know how to build them. Unfortunately, for most homeowners, they are too expensive, because the energy generation side of the equation is too costly. There are three ways to address this problem.
Reduce the cost of home-based energy generation, typically either solar or wind. That depends on technological improvements and manufacturing efficiencies by the solar panel companies, and they are busily doing their best to address this situation.
Change the cost basis for comparison – energy generation is expensive compared to the cost of electricity from coal-fired plants, but a carbon tax on those plants would automatically make solar more competitive (and raise the cost of energy for all of us).
Make the demand side of the equation – energy used – smaller. Reducing the energy used by half cuts the energy required by half, which cuts the cost by half. And typically reducing energy use has numerous other cost benefits, and often performance benefits as well.
Over the course of this series of articles, I’ll be looking at how both sides of the equation can be reduced, but the particular focus will be on getting the demand side down.
Privation is not the solution
One way to reduce the energy use of the home is simply to do less – for example, you can save a lot of hot water if you simply stop showering every other day. Other techniques are leave the heater off when it’s cold, or the AC off when it’s hot. There’s also sitting in the dark – lighting accounts for about 15% of home energy use. Strangely, most homeowners in the U.S. are unwilling to reduce their energy demand by cutting “services” in this way.
Therefore, we have to find ways to reduce energy usage while not cutting the “services” the home provides. We all need our showers, our lights, and our comfortable temperatures. The good news is that by making small changes in how homes are designed and built, typically at a very small increment to the cost of the home overall, we can build houses that use one half the energy or less, and often at a higher level of comfort and “service” than standard-built homes.
As we will see over the next few articles, we already have all the technology, and some people have the experience, to build “zero-net energy ready” houses cost effectively.
On the energy generation side, although there’s currently a premium to get to zero-net energy, over the next ten years this premium will go to zero. In fact, looking farther ahead, it may become cost-effective to get to positive-net energy – where the house is generating more energy than it needs! Such a change has world-changing implications – but we’ll cover that later in the series.
Zero-net energy homes is a huge topic, and some of the areas we’ll be covering in future posts are:
Home energy storage
Zero-net energy for existing homes
Zero-net energy and LEED
Practical steps for finding a zero-net energy home builder
Examples of zero-net energy homes
Achieving a zero-net energy home cost-effectively
How the cost-benefit equation on zero-net energy homes is likely to change over the next five and ten years
As I get started on this series, I’d love to hear your comments and thoughts on what I’ve presented here, as well as other topics I should cover in future posts.
From MIT’s Technology Review comes this column from Kevin Bullis, about a recent report from Deutsche Bank on the economic benefits of investing in new energy projects:
It argues that it’s possible to address challenges related to climate change, energy security, and the financial crisis at the same time by investing in four specific areas: energy-efficient buildings, electric power grids, renewable power, and public transportation. The report cites figures that suggest investing in these areas creates more jobs than investing in conventional energy sources because much of the old energy infrastructure is already in place. It says that “a $100 billion investment in energy and efficiency would result in 2 million new jobs, whereas a similar investment in old energy [such as coal or natural gas] would only create around 540,000 jobs.”
Of course, Obama has already pledged to do something along these lines, and the blogosphere (including me, here) has chimed in as well. But the imprimatur of Deutsche Bank adds some gravitas to the proposal.
If you want to read the report yourself, it’s here.