I built a passive solar house in the mid-1970s. As a newly minted teacher with some construction experience I self-built it in two summers. Even with me as a single Dad by the 1980s, my kids loved growing up in it. It was always a fun and interesting point of conversation between my family and others. And it saved me a ton of money on energy. A new marriage caused me to move and reevaluate keeping the solar house. But my new wife and kids are all very attached to our "different" solar house, so we're keeping it as a summer place. I would have figured that by now, these types of energy-efficient homes would be common. Passive solar homes are not complicated or especially hard to build and they don't really add that much to the initial cost. Here's mine - http://img.photobucket.com/albums/v170/aeronca65t/mccabe/passive-house-m...
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New York is a city of mostly renters, and heat has traditionally been included in the rent if only for the fact that there's been a boiler in the basement and no individual meters. New buildings now have tenants paying for heat so the landlord's not paying for open windows in January, but the incentive structure for efficiency in construction doesn't actually work well. Landlords have no direct financial gain from investing in energy efficiency if they shift the cost of heating onto the tenants. Most Americans own their homes, so I don't think there's been enough thought about this in urban, multifamily, rental environments.
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Baxt Ingui is currently involved in 8 houses targeting Passive House Certification and a bunch of others that utilize what we have learned through Passive House detailing to cut the energy bills in 1/2 or more. This includes 2 of the houses in this article. Once you understand the detailing and ideas - there is no reason not to include them in your renovation.
We have been tracking the costs and have been working with our contractors and PHA to hone details, methods, & sequencing to not only bring the costs down, but to also create a set of details that can be utilized regardless of budget. There are many details that don't involve any cost increases. For a full townhouse renovation maybe no cost increase if you are working with an experienced Passive House team to a 3 - 5% increase for someone who understands it,but where this is their build. From what we can tell so far, there really is at least a 75% decrease in energy bills.
There are plenty of people who have been building this way for years. We are also working with the same contractors we have over the past 30 years and one of the other comments was correct. There is nothing so new about this, nothing that is even that challenging for carpenters and craftspeople who have been doing good quality work for years. Once they see the details you can see their faces light up &then they keep thinking of even better ways to do other details. It is just better building!
It's an exciting time -
Michael Ingui
We have been tracking the costs and have been working with our contractors and PHA to hone details, methods, & sequencing to not only bring the costs down, but to also create a set of details that can be utilized regardless of budget. There are many details that don't involve any cost increases. For a full townhouse renovation maybe no cost increase if you are working with an experienced Passive House team to a 3 - 5% increase for someone who understands it,but where this is their build. From what we can tell so far, there really is at least a 75% decrease in energy bills.
There are plenty of people who have been building this way for years. We are also working with the same contractors we have over the past 30 years and one of the other comments was correct. There is nothing so new about this, nothing that is even that challenging for carpenters and craftspeople who have been doing good quality work for years. Once they see the details you can see their faces light up &then they keep thinking of even better ways to do other details. It is just better building!
It's an exciting time -
Michael Ingui
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I'm curious how the architects achieved a Passive House renovation for "no added cost". Compared to what? My understanding is Passive Houses need special construction techniques for airtightness, additional insulation and sometimes building material, and the windows have to be triple-glazed and hermetically sealed with space-age gaskets. Those windows ain't cheap.
I would definitely have a Passive House myself if I could afford one.
I would definitely have a Passive House myself if I could afford one.
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Actually, some of the most important developments in Passive house Design have originated in Austria, and the City of Vienna had at one point instituted an agenda for passive building in their internationally recognized subsidized housing program.
It is worth noting that the trend in Austria is moving AWAY from Passive Design - at least Passive House standards as defined by the Passivhaus Institut. There are two primary reasons:
1) The real performance of passive buildings in actual usage have not achieved their theoretically calculated values. In part because passive houses must be "used" properly - the residents are NOT allowed to open windows for ventilation. This requires teaching the residents how to "use" the house and demanding that they only ventilate via mechanical systems with energy recovery. Otherwise, the house doesn't perform as advertised!
And: most people like to open their windows for a little air every day...
2) Mechanical systems need maintainence, and eventually replacement. Therefore the cost/benifit analysis for the mechanical energy systems doesn't really add up.
There is a new movement towards highly efficient, well insulated buildings that are simply built and keep mechanical systems at a minimum. This way, people can use the house as they wish, and can ventilate in the old-fashioned way: just open the window.
Many have come to believe that this is a more sustainable way of building: less expensive, more robust and built for the future.
It is worth noting that the trend in Austria is moving AWAY from Passive Design - at least Passive House standards as defined by the Passivhaus Institut. There are two primary reasons:
1) The real performance of passive buildings in actual usage have not achieved their theoretically calculated values. In part because passive houses must be "used" properly - the residents are NOT allowed to open windows for ventilation. This requires teaching the residents how to "use" the house and demanding that they only ventilate via mechanical systems with energy recovery. Otherwise, the house doesn't perform as advertised!
And: most people like to open their windows for a little air every day...
2) Mechanical systems need maintainence, and eventually replacement. Therefore the cost/benifit analysis for the mechanical energy systems doesn't really add up.
There is a new movement towards highly efficient, well insulated buildings that are simply built and keep mechanical systems at a minimum. This way, people can use the house as they wish, and can ventilate in the old-fashioned way: just open the window.
Many have come to believe that this is a more sustainable way of building: less expensive, more robust and built for the future.
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What an encouraging article. We have had passive buildings in Northern New Mexico since the 70's and even earlier in historic buildings, but most buildings have not been using the lessons of passive building, so the only way to get one of these gems is to build one's own. Most of us prefer to buy something already built by people who know more than we do.
When will the building industry in the Southwest, and other parts of the US start using the known technology of passive building?
When will the building industry in the Southwest, and other parts of the US start using the known technology of passive building?
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In the 1970's, in upstate NY where winters go down to -20's and less, I visited a completely passive home of two stories, fully glass fronted, three bedrooms, two baths, huge living/dining are. They had had to put in electric baseboards to get a mortgage, one of the higher costs so often remarked, but never used it. Also solar hot water, etc. Cool in summer, warm in winter, completely green.
I also have two books on this published in the 1970's. And my brother, a sheet metal worker used two passive heat window units, fashioned by himself, to heat his Brooklyn apartment. in the 1960's.
FINALLY, NYT and NYC wakes up!!!
Alison: do your research. Most Times articles today seem to be straight from an interview w/o any context or background/history analysis. One would expect more.
I also have two books on this published in the 1970's. And my brother, a sheet metal worker used two passive heat window units, fashioned by himself, to heat his Brooklyn apartment. in the 1960's.
FINALLY, NYT and NYC wakes up!!!
Alison: do your research. Most Times articles today seem to be straight from an interview w/o any context or background/history analysis. One would expect more.
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I couldn't agree more. As Editor in Chief for Architecture and Engineering for McGraw-Hill in the 1970s, I published the first books on active and passive solar architecture and energy by authors such as Bruce Anderson, Malcolm Wells, Jan Kreider and Frank Kreith. If you are going to get on the passive and active solar energy bandwagon now, at least do some research!
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Patricia--I believe you are mixing 70's era "passive solar" with what this article is about: Passive House. They are not the same thing.
Today's passive house designs most definitely take into account solar gain, but are very different from the solar storage and distribution designs of that era.
Today's passive house designs most definitely take into account solar gain, but are very different from the solar storage and distribution designs of that era.
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I presume it is the writing at fault here, but I fail to see any references to systems needed to raise or lower ambient temperatures, or moderating humidity. Wishing does not make it so. When there is a substantial temperature and/or humidity difference between inside and outside energy MUST be expended in some way to produce an interior environment suitable for human habitation. Insolation - i.e. allowing the entry of solar energy through glass - can raise temperatures in the heating season, to a point, but the cooling season does not have a parallel.
I would have to assume that air-source heat pumps are used in these buildings to produce the desired interior temperatures, but there seems to be zero reference to ANY system.
A further concern is de-humidification in summer. Allowing this to occur only by cooling the interior air while allowing the ERV to perform does not totally prevent possible condensation within walls or roofs. Proper detailing is needed with attention paid to vapor barrier location within walls and roofs to guarantee against condensation.
Unfortunately the defects of this article from a technical standpoint may generate copycat design work from the uninformed and unsophisticated within the building industry, and subsequent sales to unsuspecting buyers who will face a nightmare of possible building failure.
Shame on you, NYT.
I would have to assume that air-source heat pumps are used in these buildings to produce the desired interior temperatures, but there seems to be zero reference to ANY system.
A further concern is de-humidification in summer. Allowing this to occur only by cooling the interior air while allowing the ERV to perform does not totally prevent possible condensation within walls or roofs. Proper detailing is needed with attention paid to vapor barrier location within walls and roofs to guarantee against condensation.
Unfortunately the defects of this article from a technical standpoint may generate copycat design work from the uninformed and unsophisticated within the building industry, and subsequent sales to unsuspecting buyers who will face a nightmare of possible building failure.
Shame on you, NYT.
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Hi James, yes, you’re absolutely right. There’s a lot more to Passive House than the building enclosure. However, that building enclosure is SO important to Passive House, I can understand Ms. Gregor needing to focus on it. As you correctly reasoned, there is a heating and cooling system with thermostat control in passive houses. And, yes, most are (very small) air-source heat pumps although other system types are possible (we’re installing a geothermal heat-pump in one we’re working on now). Surprisingly, solar gains have become slightly less important in modern Passive House; we really depend on that enclosure. Regarding the humidity, we see the Energy Recovery Ventilator handling much of the potential incoming humidity, with that small heat pump wringing out the rest to achieve excellent desired indoor comfort. And, oh my gosh, you’re so spot-on about the importance of ‘detailing’ to get it right. That’s why both PHI and PHIUS require precise modeling and field testing. But with that, you get the best part: In New Jersey, all PHIUS passive house automatically achieve NJ Energy Star Homes Tier 3 rebates which can be quite significant. (‘Quite’ being up to $26K). And throw in the effective revenue streams from no utility bills anymore and you’ve got a powerful idea here.
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"In New York, small heating and cooling systems are generally included in passive homes." (Paragraph 3)
The passive house standard began in Germany, where the summers are relatively mild. There's no need for cooling, and heating needs can be met with body heat and the residual heat from stoves, dryers, coffee makers, etc.
In New York, you're correct that a small heat pump (air conditioner) is needed to bring the indoor temperature below the outside temperature. But from there, the insulation and lack of airgaps help ensure that heat transfer from the outside is low despite the temperature difference between the outside and inside.
The passive house standard began in Germany, where the summers are relatively mild. There's no need for cooling, and heating needs can be met with body heat and the residual heat from stoves, dryers, coffee makers, etc.
In New York, you're correct that a small heat pump (air conditioner) is needed to bring the indoor temperature below the outside temperature. But from there, the insulation and lack of airgaps help ensure that heat transfer from the outside is low despite the temperature difference between the outside and inside.
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While James criticisms have validity, I feel he is too harsh. The New York Times, is after all, a newspaper not an architectural journal. Presumably an architect would have the knowledge and skills to design in systems and to specify construction methods which would address James' concerns.
The article conveys the potential of a very real way to address environmental and energy challenges of unhealthy air pollution and global climate change that come with conventional fossil fuel energy sources. By showing local examples and bringing these facts to the public in a very readable way, the reporter has made a valuable contribution.
The article conveys the potential of a very real way to address environmental and energy challenges of unhealthy air pollution and global climate change that come with conventional fossil fuel energy sources. By showing local examples and bringing these facts to the public in a very readable way, the reporter has made a valuable contribution.
4
Passive houses are nothing new. Most old and historic houses and buildings were designed for passive air flow and exchange. After 40 years of doing so, we've found that retrofitting these quality built heritage structures is easily and cost effectively done. Considering the massive amounts of energy needed to make new and unsustainable materials used to build today, it is essentially impossible to build anything new that is sustainable, green or passive.
In passive or LEED certified structures an exchange of stale air with outdoor air often happens with electric motors. These units have shown to fail periodically and the homeowners rarely know it's happened. Operable windows are critical for a true and natural exchange of air. I've seen mold and illness as a result of these super tight buildings, houses and units not operating as designed down the road. Are most of these structures sustainable in a lasting way? Is the work being done with quality materials and a true artisan's hand? We think not. Bob & Pat Yapp
In passive or LEED certified structures an exchange of stale air with outdoor air often happens with electric motors. These units have shown to fail periodically and the homeowners rarely know it's happened. Operable windows are critical for a true and natural exchange of air. I've seen mold and illness as a result of these super tight buildings, houses and units not operating as designed down the road. Are most of these structures sustainable in a lasting way? Is the work being done with quality materials and a true artisan's hand? We think not. Bob & Pat Yapp
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I'm not sure why Germany gets all the credit for "passive house" design philosophy. The approach that is described sounds very much like Canada's R2000 program which originated in Saskatchewan in the 1970s.
1
Perhaps because the R2000 program is obsolete? Completely obsolete?
If you think about the environmental disasters we face -- fossil energy depletion, global warming caused by CO2, growing resource constraints -- it's astonishing that passive house design isn't mandated for all new construction, and that we don't have massive state subsidized programs to retrofit older buildings to these standards. Heating and air conditioning represent something like 40% of our national energy budget. Slash that by three-quarters and maybe we can stop poisoning our groundwater with fracking, and stop poisoning our international reputation with Permanent War.
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Fine Homebuilding Magazine has had many great articles on real-life Passive Houses and low-energy houses the last few years. Many architects and smaller home-builders across the country going in this direction. It is definitely the future and great to see this coverage in the Times. There is so much focus on transportation and its energy impact. The built environment has been comparatively neglected. Developer Carter Scott in Massachusetts has even built entire spec. house neighborhoods to net-zero and low-energy standards, including some units that meet affordable housing mandates. In contrast to a highly labor intensive net-zero house in Vermont recently profiled in the Times, the passive house is much simpler and lower maintenance.
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Passive house construction requires a committed craftsman. It is an investment in the future and really makes a building a "machine for living" as Le Corbusier famously pronounced. What this means is that we would benefit greatly from an apprentice system where contractors are properly trained. It also means that always choosing the low bid is short term thinking. It takes time and planning to achieve a completely sealed building envelope. As is usual in the NY Times, we're discussing $2.5 to 5 million dollar homes. Let's see more articles on how we can apply this technology successfully on a $200,000 home.
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Experience Passive House in action at the Phoenicia Library, Phoenicia, NY - the first library built to passive house standards in the US. www.phoenicialibrary.org
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What are the exact costs involved in these "passive houses"? Please someone answer the question, as the NYTs seems to be very happy these days with the dichotomy between the haves and the have nots! (Last week's ridiculous articl about kids choosing $14M homes for their parents-can we just roll our eyes?)
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The cost likely comes from the need for extra insulation, triple-pane windows, and architects/engineers who are capable of achieving such a high performance standard.
If you are curious about how a Passive House building looks and feels, you are welcome to visit the Phoenicia Library in the Catskills. After our library was destroyed by a fire, we became the first library in the US to build to Passive House standards. Keeping our library at a steady 70 F 24/7 this bitter February, our heating cost was about $60. We are a small rural library and this is wonderful for our budget as well as the environment.
We are happy to talk to people about the costs, benefits etc of doing a PH build (ours was a retrofit after a gutting). You can ask for Liz Potter, director at the library.
http://phoenicialibrary.org
We are happy to talk to people about the costs, benefits etc of doing a PH build (ours was a retrofit after a gutting). You can ask for Liz Potter, director at the library.
http://phoenicialibrary.org
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The city may take a rather dim view of those unsupported window units at 803 Knickerbocker Ave. Generally, some kind of exterior brackets are required in addition to window frame attachments.
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I was wondering what happens as the building gets older and needs repairs. Will it be impossible to bring back to "passivity", will it be expensive to fix up, will it fall down? Also, what happens if the people in the house get an airborne disease, like Legionaire's Disease? Does the house become unlivable or have to be expensively fumigated? Fleas? Bedbugs?
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Generally, passive house construction is designed to last a lot longer. For example, by preventing air (and moisture) from getting into the structural assembly, materials-performance continues as designed for extended periods. Comparing the resiliency of first circa 1990’s German passive houses (e.g. Darmstadt-Kranichstein) to some of the mid 90’s US conventional construction is both sobering and inspiring.
Regarding air borne pollutants, this is a place where the Passive House shines. Using a Heat or Energy Recovery Ventilator, the indoor air is exchanged with fresh, filtered, outdoor air every few hours. That indoor air comes from all the unwanted-air areas of the home: bathrooms, laundry rooms, kitchen areas, basements, attics, craft or workshop areas. The fresh air is delivered to other areas like livings rooms and bedrooms. Thus, the exhaust areas having a slightly negative pressures so anything yucky never gets to other parts of the home. And then the new incoming air is filtered clean. All this is done with virtually no loss of energy. The effect is a super clean, fresh home. Those who own passive houses can attest to this.
Regarding air borne pollutants, this is a place where the Passive House shines. Using a Heat or Energy Recovery Ventilator, the indoor air is exchanged with fresh, filtered, outdoor air every few hours. That indoor air comes from all the unwanted-air areas of the home: bathrooms, laundry rooms, kitchen areas, basements, attics, craft or workshop areas. The fresh air is delivered to other areas like livings rooms and bedrooms. Thus, the exhaust areas having a slightly negative pressures so anything yucky never gets to other parts of the home. And then the new incoming air is filtered clean. All this is done with virtually no loss of energy. The effect is a super clean, fresh home. Those who own passive houses can attest to this.
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Passive houses are designed to be nearly airtight. They have mechanical ventilation systems that filter incoming air, so the indoor air quality is much better than in a typical house. You are much more likely to suffer airborne illnesses in a typical house where the air you breathe comes through a moldy basement. Typically they are built to much higher standards than required by building codes, so they should need fewer repairs.
The features that make them so efficient, insulation, efficient windows and air barriers, have no moving parts, so they will be effective indefinitely. As the story mentioned, if the heat goes out in winter, from a power failure or whatever, the house will stay warm enough for days.
The features that make them so efficient, insulation, efficient windows and air barriers, have no moving parts, so they will be effective indefinitely. As the story mentioned, if the heat goes out in winter, from a power failure or whatever, the house will stay warm enough for days.
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Could you possibly tell us more about retrofitting to passive standards? What does it involve? What are some companies that do it?
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There’s a lot of great info at the two Certifying Authorities: PHI (www.passiv.de/en/) and PHIUS (www.phius.org/home-page) including listings of Certified Passive House Consultants that could get you started: http://planer.passiv.de/de/planer/map and www.phius.org/find-phius-certified-professionals.
Two excellent introduction videos on Passive House that I see often are: https://www.youtube.com/watch?v=CasrjYhZB1M&list=PLafhZNLQg5qloFE2Ir... and https://vimeo.com/32007211. But my favorite video is this Belgium advertisement for Pasivehaus: https://www.youtube.com/watch?v=ms9piTYk2Os. Hilarious … and poignant. Enjoy!
Two excellent introduction videos on Passive House that I see often are: https://www.youtube.com/watch?v=CasrjYhZB1M&list=PLafhZNLQg5qloFE2Ir... and https://vimeo.com/32007211. But my favorite video is this Belgium advertisement for Pasivehaus: https://www.youtube.com/watch?v=ms9piTYk2Os. Hilarious … and poignant. Enjoy!
2
Wonderful that you and the Times have written and published this piece. Our built environment is the most significant contributor to greenhouse gas emissions but we can turn that around and actually create places to live, work and learn that keep us healthy, improve our well being and actually export energy. The more this message gets into mainstream media the sooner we can collaboratively realize this critical goal. Keep up the great work of spreading this meesage!
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So glad to see this here; wish it was getting more attention.
What a terrific effort. If we were more sane, we would all be working together to make these things happen. A friend in the building trade says it's hard to persuade investors and designers to put energy savings up front, even though it saves scads of money.
What a terrific effort. If we were more sane, we would all be working together to make these things happen. A friend in the building trade says it's hard to persuade investors and designers to put energy savings up front, even though it saves scads of money.
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I would expect that this approach will be city code once empirical evidence with sufficient data points regarding performance comes in. The city will be hard pressed to hit 80/20 without this.
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