GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted
Green Building News

Little House, Big Energy Efficiency in Boston

A local builder takes a “lay builder” approach to the Passivhaus standard as he reconstructs a 19th-century cottage

Image 1 of 2
Deconstruct, reconstruct. Built in 1850, the Pratt House, a cottage and former gunsmith’s shop in Boston’s Roxbury neighborhood, is being reconstructed to a level of energy efficiency comparable to that of the Passivhaus standard.
Image Credit: Placetailor Inc.
Deconstruct, reconstruct. Built in 1850, the Pratt House, a cottage and former gunsmith’s shop in Boston’s Roxbury neighborhood, is being reconstructed to a level of energy efficiency comparable to that of the Passivhaus standard.
Image Credit: Placetailor Inc.

Simon Hare, a builder and design consultant based in the Roxbury section of Boston, decided to apply basic Passivhaus precepts, rather than the technical, detailed modeling often deployed for Passivhaus projects, to the reconstruction of a house in his neighborhood.

The scale and legal disposition of the building, known as the Pratt House, also mesh well with Hare’s goal of building a house that, even without renewable-energy sources, will be highly efficient. For the purpose of addressing flaws in airtightness and thermal resistance, for example, it helps that the house is only 750 sq. ft. – about 6% smaller than most entries in the Department of Energy’s Solar Decathlon. And for the purpose of seeing the project through on Hare’s own terms, it also helps that the house is owned by his family.

Discussing his approach to the project for a story by CNET, Hare said he hopes the project will show that construction of near-net-zero-energy homes is within reach of everyday building professionals.

“The Passivhaus approach is very techie, which I think is its Achilles’ heel – it appeals to geeks but not the layman, the lay builder,” Hare told CNET News. “We can prove we can do this without hiring consultants and using software to do the energy modeling. We’ll just use precedent and established rules of thumb.”

The exterior walls feature structural insulated panels – in this case 12 in. foam cores sandwiched between plywood sheets – and a 1-in. layer of rigid insulation on the exterior-wall surfaces, which Hare says bring the walls to R-50. All joints were taped or sprayed with foam.

Hare and his company, Placetailor, hope to finish the project by the end of October, as the house nears one of the ultimate tests of energy efficiency – the Boston winter.


  1. Jamie Wolf | | #1

    This just makes me angry
    Here again we have a gross mischaracterization of Passive House (not Passivhaus). Please read the comments on the Cnet story site from Mike Kernagis and Katrin Klingenberg, the founders of the US Passive House Institute, the only organization authorized to certify Passive Houses in this country.

    Passive House is not a prescription, it is a rigorous and uncompromising method supported by the most reliable tool we have to predict the "energy balance" in a building. To appropriate its principles without adhering to its methodology is an impossibility.

    Simon Hare's posture reminds me of the irate homeowners I've seen confront building and zoning officials over the years - outraged over regulations that prevent them from building a deck how and where they want to. Disparaging professionals as unneccesary for something so "simple" is one of their naive arguments.

    But Simon Hare and Placetailor are not who I have a beef with(I'm glad to hear they recently attended PH training). They will certainly build a "highly efficient" building.

    I'm disappointed in the GBA for championing his seat of the pants "layman's" approach to achieving what we all need to recognize and require - that producing successful low load buildings is going to require a level of intelligence and thoughtfulness that is not derived from the seat of the pants.

    I'm also disappointed that the GBA would become one of the reflecting surfaces for the web echo chamber that produced this story. I have the highest regard for the editorial reliability of Environmental Building News and their rigor in this regard. There is way too much "sounds good" information floating around the web that gets no scrutiny and then is repeated over and over. For whatever reason, Passive House has been misappropriated and misunderstood in this way many times (including here at the GBA).

    It's about time we saw a well researched and responsible review of the Passive House method in detail, as well as ongoing discussion of its merits and liabilities. Just as long as they are responsibly reported. That's why I'm a paying subscriber!

  2. GBA Editor
    Martin Holladay | | #2

    Jamie, take a deep breath
    It seems to me that your comment is an overreaction to a news story. Reporters like Richard Defendorf shouldn't be attacked for reporting on the statements of Simon Hare.

    Your comments, along with those of Mike Kernagis and Katrin Klingenberg, which you cite, are a little worrisome. (I respect Mike and Katrin very much; they're doing excellent work.)

    You called our story "a gross mischaracterization of Passive House (not Passivhaus)." Mike complained of Simon's "attempt to capitalize on our good name for his marketing purposes." Katrin complained of "misinformation that is being spread in the name of Passive House."

    Everyone needs to take a deep breath. To my knowledge, no one owns the words "passive house." They were used in the solar house movement before Katrin was born.

    I was the first U.S. journalist, to my knowledge, to publish a story about the Passivhaus movement; my story appeared in the February 2004 issue of Energy Design Update. When I heard of Katrin's plans to found an institute in Urbana, I urged her to adopt the term "Passivhaus" -- the term I used in my reporting -- to avoid confusion with passive solar houses. She decided instead to use the phrase "passive house."

    Note than in the United Kingdom, all the organizations refer (in English) to their standard as the Passivhaus standard, following the Energy Design Update protocol. See, for example,

    I think we should all work together. I have always striven to report accurately on the Passivhaus standard. But let's not get proprietary about the phrase "passive house." Let's not insist that a reporter can't refer to the standards by the German spelling, which is standard practice in Europe. And let's share information, not build walls around our professional status.

  3. GBA Editor
    Martin Holladay | | #3

    Some additional perspective
    One more point concerning whether there's anything wrong with building a superinsulated house that aims for Passivhaus performance WITHOUT going through the steps required for official certification: remember that Katrin Klingenberg, the founder of the Passive House Institute in Urbana, Illinois, did exactly that for the first house she built. She didn't bother to get it certified (at least for several years). When I interviewed her in the early spring of 2004, her house still hadn't been tested with a blower door.

    Not everyone will choose to go the certification route. But let's not gang up on people who build without certification.

  4. wolfworks | | #4

    The name means something
    Now that I'm breathing smoothly let me continue to (calmly) take issue with the reporting. We have seen here (GBA) and elsewhere references to the Passive House standard being used as a project benchmark without the "inconvenience" of adhering to or actually following (and I would suggest fully understanding) the methodology.

    The argument being made here is that all those fussy details aren't necessary to carefully consider and that this work can be approached intuitively. That notion is anathema to the principles that form the foundation of Passive House practice - no matter how you spell it (take that up with Katrin - I'm honoring her request).

    Because of my respect for EBN and FH I expect such misapplications, especially of a methodology and protocol that many (I count Martin among them) consider exceptional, to be commented on, even as we praise the initiative that Simon is taking.

    We would not advocate anyone claiming to achieve a LEED rating without complying with their protocol, a HERS rating without theirs, etc. I am perfectly fine with the claim made early on in the reporting that this will be a highly efficient building. I just expect the Passive House comments to be scrutinized and responsibly qualified.

    I am also uncomfortable with the unquestioned assumption that this work can be done by "just using precedent and established rules of thumb". Isn't that what we are here trying to overcome?

    Let's shift our attention from the use of the name Passive House to the heart of my contention: the name is now (whatever precedents suggest about its generic meanings) being used to refer to a specific methodology that continues to be poorly understood. We would all benefit from exploring and understanding its foundations more carefully. Nerdy or not!

  5. GBA Editor
    Martin Holladay | | #5

    Be careful not to confuse the statements of Simon Hare -- the subject of this news report -- with the statements of the GBA Web site. If you have found an inaccuracy in our encyclopedia or informational articles, please point out the problematic sentences and we'll do our best to correct them.

    And actually, James, I have heard of builders who have gotten frustrated with the requirements of other programs -- including the Energy Star Homes program -- and have stated in articles and letters, "I'm no longer going to jump through the Energy Star Homes hoops, but I'm going to continue to build to the same standard. It's just not worth it to me to stay in the program."

    Many small builders or young builders choose not to enroll in programs or seek certain certifications. But it's perfectly acceptable -- in fact, wonderful -- for such builders to talk about Passivhaus, refer to Passivhaus in interviews, strive for Passivhaus, and learn from Passivhaus builders.

    If a commercial builder is trying to illegally profit from homes that don't meet Passivhaus standards -- for example, by printing advertising that falsely claims, "McMansion Builders is selling new homes for $120,000 that meet the stringent Passivhaus standard!" -- then go ahead, take them to court. But let's not nip discussion in the bud -- especially builder-to-builder discussion by people genuinely interested in energy-efficient construction.

  6. Daniel Morrison | | #6

    We can report on results this winter
    _... become one of the reflecting surfaces for the web echo chamber that produced this story_

    **Great sentence, Jamie, thanks.**

    We'll follow up on this house in a few months, after it's finished, so that we can measure its performance.


  7. Dark Lad Slim | | #7

    Superinsulated house, Passive House and PassivHaus
    In the early 80's, 1984 I think, the book "Superinsulated House Book" was published. The energy performance requirements for such homes was not really very clearly established - though there were some suggested performance targets based upon Heating Degree Days. It strikes me that a well insulated building without the detailed analysis can only ever be called Superinsulated and can not justifiably claim any association with a PassivHaus (PassivHaus is the refinement of the Superinsulation concept). It strikes me that the work Simon Hare harks back to this earlier era.

    As for 'Passive House' or 'PassivHaus' - In the UK the term 'Passive House' has an association with the passive solar house. This factor, and because of our close economic/ geographic ties to Germany (compared to the USA) I think that the name has transferred much more readily.

    Passive solar homes are, as I believe William Shurcliffe noted in the 80's, subject to thermal discomfort resulting from high temperature fluctuations and for that matter a superinsulated house based upon a rule of thumb can also lead to discomfort (i.e. no calculation 'techniques' can still result in downdraft discomfort , radiant asymmetry and stratified air temperature all as a result from inappropriate glazing specification, also heating systems may be removed/undersized leading to low indoor temperatures which again leads to discomfort.) In this respect thermal comfort distinguishes a PassivHaus from a passive solar house and for that matter a superinsulated house.

    I did an interesting study the other day and found that a superinsulated "PassivHaus principles" approach with good daylighting will on average lead to a home that consumes about 30%-45% more than a fully resolved PassivHaus (I've checked this using PHPP!)

    So, is this good or sloppy? Furthermore is this "energy efficiency comparable to the Passive House standard"?

  8. GBA Editor
    Martin Holladay | | #8

    Superinsulated and passive solar
    Dark Lad Slim,
    Thanks for your perceptive post. You may be interested in reading my most recent blog, which also mentions Nisson and Dutt's landmark 1985 book, The Superinsulated Home Book.

    You note that in the U.K., the term "passive house" is often confused with passive solar houses. The same is true in the U.S., which is why I have consistently argued in favor of the "Passivhaus" spelling.

    You note that "Passive solar homes are, as I believe William Shurcliffe noted in the 80's, subject to thermal discomfort resulting from high temperature fluctuations and for that matter a superinsulated house based upon a rule of thumb can also lead to discomfort." This WAS true, certainly in the early 1980s. I was one of those "passive solar house" builders guilty of building houses with too much south-facing glazing. These houses tended to overheat, especially in March and April. But these mistakes were made 25 to 30 years ago, and have long since been correctly by all but the stupidest builders.

    Gene Leger's perception that superinsulation techniques are more important than passive solar principles was made in 1977. This is an old argument. Superinsulation has long since won the passive solar versus superinsulation argument.

    I don't know any builders interested in superinsulation who are still using glazing ratios from passive solar house books of the early 1980s. This accusation is a red herring -- a straw man -- choose your metaphor. Those of us committed to superinsulation learned these lessons a long time ago.

    I've gotten in trouble before for listening respectfully to builders who use rules of thumb. But I'll say it again: some Passivhaus advocates exaggerate the discomfort experienced by occupants of superinsulated houses. Many, many, comfortable superinsulated houses have been built by conscientious builders who use methods other than the strict Passivhaus standard.

  9. Dark Lad Slim | | #9

    I don't doubt that superinsulation can result in excellent comfort, providing that it is climatically considered. As I'm sure you are aware Fanger undertook a great body of research into thermal comfort and provided some fairly reliable means of assessing comfort conditions. With this in mind if the pane temperature is maintained about 16-17C on the coldest day of the year then comfort can certainly be maintained. As the US covers such a broad very range of climates it has been possible, in some regions, to achieve an appropriate glazing spec for many years.

    I'm glad that the superinsulation vs passive solar argument is over in the USA, it is I fear still very much misunderstood in the UK. So I have to admit that in this respect I'm somewhat surprised at your statement i.e. we still have an industry of stupid builders/designers that "design in" overheating through ignorance rather than sizing openings appropriately. But then you did say "I don't know any builders interested in superinsulation" such people are in short supply in the UK at least.

    Finally, as suggested above, a rule-of-thumb "PassiveHaus principles" home that consumes about 30%-45% is pretty shocking. It's just an 'average' builder that uses superinsulation that is living of a 'trendy' label that means something. (This is not to say that such a home is worthless - it's still better than 90+% of the new build but it is gross misrepresentation within the chosen marketplace.) In this respect isn't "PassivHaus principles" a case of the emperors new clothes? to look at your blog ;-)

  10. Dark Lad Slim | | #10

    "consumes about 30%-45% is pretty shocking" should read "consumes about 30%-45% more than a PassivHaus is pretty shocking."

  11. GBA Editor
    Martin Holladay | | #11

    Thermal comfort and William Shurcliff
    Dark Lad Slim,
    Whether or not a house that consumes 30% to 45% more than a Passivhaus is "pretty shocking" or cause for rejoicing depends on one's perspective. Certainly such houses would be a huge step in the right direction.

    You're absolutely right that a key element of thermal comfort is appropriate window specification. That's why an investment in triple glazing makes so much sense in cold climates. Even if triple glazing seems a stretch in terms of fuel savings, these windows provide vastly higher levels of occupant comfort.

    My perspective on the "superinsulation versus passive solar" debate is, indeed, the perspective of a builder interested in energy efficiency. Here in the U.S., that means a builder who has long attended EEBA conferences (EEBA used to stand for the Energy Efficient Building Association, and later became the Energy and Environmental Building Association) and who is familiar with Home Energy magazine and Energy Design Update.

    One of the key documents in the "superinsulation versus passive solar" debate was William Shurcliff's press release of June 1979. If you haven't read it recently, it's worth rereading:

  12. furniturefarmer | | #12

    interesting debate
    Regarding "Passive House" vs. "Passivhaus" I honestly don't really understand the issue. I use the words Leadership in Environmental and Energy Design--LEED-- because that's what the USGBC decided to call their standard. I use the term Passive House because that's what PHIUS decided to call their standard. Martin, the fact that the words "passive house" were used before Katrin was born is precisely the point. This was a long, long time ago and the words meant something much more vague. Katrin and PHIUS revived a dead phrase (in the U.S.) and gave it a totally new and specific meaning. In fact, I wouldn't be suprised if, legally speaking, PHIUS does in some way own the combination of words "Passive House" and indeed maybe this is a good thing.

    Regarding the "newsworthiness" of the above story it occurs to me the whole point of the story is that a "lay builder," to whom the PH approach apparently does not appeal because it is too techie, is going to build a Passive House. But Jamie Wolf reports that the builder is actually attending the Passive House training sessions. Confusing.

  13. Jesse Thompson | | #13

    Superinsulated house, Passive House and PassivHaus
    Dark Lad Slim,

    Could you quickly quantify what the input differences were between the "super-insulated, PH principles" house and the true PH in the model you mentioned?


    Jesse Thompson

  14. Graham Irwin | | #14

    Perhaps I lack the sophistication and/or patience to follow this thread through its twists and turns, but to me, the whole debate starts and ends with this issue:

    - Mr. Hare seems to be advancing the view that the Passive House (PassivHaus) standard and associated modeling and design is cumbersome and unnecessary. His stated mission is to prove that guessing is "better." In fact, the BASIS of the Passive House (PassivHaus) standard IS to design and NOT to guess, and that project specific calculations are necessary to reveal the optimal cost/benefit point. The analogy Ms. Klingenberg provided of bookkeeping is apt - efficiency measures cost money, and face diminishing marginal return returns. The only relief in the ever-steepening cost vs benefit curve is brought by knowing where one's project is on that curve, reaching a point where mechanical equipment reductions "reward" efficiency, and adjusting the details of one's project to reach that point most cost effectively with quantified feedback as to the affects on one's adjustments. Guessing means one of three things: 1) You spend too much, 2) you spend too little, or 3) you get lucky. I have been accused of being a curmudgeon, but my bet is on outcomes #1 or #2 most of the time.

    As to the common sense argument, one might ask if it makes sense to work for a well-insulated, airtight shell to only then install leaky, inefficient windows, effectively cutting holes in your carefully constructed building and undoing much of the time, effort and expense.

    I personally don't care how you spell the standard or what Mr. Hare does with his own building or the buildings of his clients. I do care that he, this publication and others do not assist in obfuscating what is the most promising and common sense approach to combating climate change at our disposal.

    Graham Irwin
    essential habitat

  15. Roger M. Woodbury | | #15

    Passive House...well, sort of....
    Years ago when I was between careers I sold cars for a big dealership in Boston. The sales manager said one thing that has stuck with me for many years: "Nothing happens until someone sells something." I think this applies particularly to the discussion regarding Passive House and the abridging of Passive House by guessmanship to achieve a highly performing building. I see several issues here, all relating to the concept of "selling something", in this case, Passive House vs something else.

    Most people's eyes will glaze over when when one tries to discuss Passive House concepts with them. The reason for this is that most people haven't the faintest idea how to build anything, much less a high performance home. Mention "Energy Star" or "LEEDS" and their eyes tend to brighten up because the selling of these TERMS is extremely well underway, and they have become recognized as "the standard", rightly or wrongly.

    For most people cranking up the level of comfort in a home relates more to turning up the thermostat than to analyzing what is happening mechanically in the house. Unless there is a dedicated movement at the Federal level to change the thinking of our civilization toward energy use, and it is codified in some way, merely using a little more fossil fuel directly, or indirectly in the form of electricity will suffice for most consumers and most builders.

    There needs to be some sizzle added to the steak of the Passive House name. It must be sold and become recognized as not just another building concept, but as an entire technological and philosophical approach to building and living in structures. I have suggested that the concept of franchising the Passive House concepts is potentially restricting to the much needed dessimination of information sorely needed in the US, but some method of establishing in the general public's eye that Passive House is much more than another layer of insulation stuffed here or there, seems appropriate.

  16. furniturefarmer | | #16

    Editorial issue
    Graham, I wouldn't be too hard on GBA for reporting on the story. After all, it is the builder who is claiming to be doing a Passive House without actually doing a Passive House. In fact, if it isn't reported on, it can't be held to the light and examined for what it is--and it is a blog after all, not the New York Times, so stirring up a little debate is expected. On the other hand, there is an editorial issue here; for instance, I don't t think you'll be seeing this article anytime soon on GBA or EBN: "Architecture Firm Going For LEED Platinum Building Without Following Cumbersome Certification Process." My pont being: it certainly would have been nice for the author to be a bit more critical.

  17. GBA Editor
    Martin Holladay | | #17

    To be fair
    Simon Hare has is no way misrepresented what he is doing. Loud and clear, he has told everyone that he is NOT using the PHPP software; instead he is using a superinsulation approach. Heavens, it's no crime to use the word "Passivhaus" or the words "Passive house" when describing efficient buildings. Anyone with their ears open is inspired by the Passivhaus concept. Hare happens to be talking about it -- and telling anyone who cares to listen about his construction project.

  18. Simon Hare | | #18

    Don't throw rocks when living in a passive house...
    Seems like we've stirred up some trouble with our constructive criticism of the American Passive House movement (which we're proud members of). I'm glad to see the the GBA keeping an enlightened and professional outlook on the debate that's ensued.

    One important lesson I've learned from this experience: don't throw rocks when you're living in a passive house. But I guess I started this friendly debate, so I might as well continue.

    I grew up in a neighborhood of passive houses in the high desert of Israel, where solar access is guarded in the local ordinance and setbacks along the East/West edges of properties are minimized to bring houses closer together and create shaded walkways with their own protective microclimate. In my old 'hood, passive house design is common sense. In my new 'hood (Roxbury, and the US for that matter), it isn't. I'm interested in showing that passive design and construction is in fact common sense even in this region, only that we've lost touch with this understanding of buildings and climate. Simply put, I want to see the industry come back to its senses.

    With Placetailor's Pratt House project we were frustrated by a lot of recent press that was painting a picture that paid little attention to the past, and that obscured rather than explained the underlying knowhow of energetically efficient buildings. We decided to challenge ourselves, and our colleagues, to clear some of the mist surrounding the Passivhaus Standard by designing a house that'll meet the performance standards without relying on computer models. In other words, we chose to build a real model. We relied on our wits, our knowledge, the knowledge of those who designed and built such stuctures before us, and on a good amount of careful attention to detail. We think we've done good, and are eager to prove it come winter when the house is complete and occupied.

    Perhaps the GBA/EBN family would consider reporting on the Pratt House first thing in 2010? Surely some performance data from Boston's coldest months, whether standing in favor of our argument or against it, would serve to inform the debate.

  19. Katrin | | #19

    Martin's invite to comment - thank you
    Dear Martin,

    I don't see Jamie attacking the news story or journalist, he gives credit to the project. He is criticizing a trend that he is seeing in EBN's reporting on Passive House overall.

    I agree with his point of view that the information on EBN on Passive House does not seem well researched and understood. The most recent example being the quote that it helps that the house is 6% smaller than the Solar Decathlon houses. Small houses are the hardest, because of the unfavorable surface to volume ratio.

    It seems to me that there is great confusion out there. Useful solar gains in a Passive House are actually overall less than in a standard conventional building. That's why its called Passive House, not Passive Solar. Those two are very distinct from each other.

    The name question has been discussed between the Passivhaus Institute in Darmstadt and PHIUS and the decision fell towards the English term for a reason: Passive Housing has been for a long time and still is, as you point out, a building science principle based on physics. We feel that the use of PassivHaus, as the British partners like to spell it, evokes the notion of branding. In our opinion Passive House is not a brand but a universal energy standard which has started to be recognized worldwide. This is why Passive House Institute in Darmstadt and Passive House Institute US are consistently using "Passive House".

    In regards to the Smith House, my house has been certifiable from the beginning, was the first Passive House project entered into the first English translation of the handbook and has been optimized in PHPP by Dr. Feist. The methodology used, modeled PHPP results as well as measured performance have been published and are publicly available.

    Thank you, Martin, for your invite to comment.

  20. Declan B. Keefe | | #20

    I am one of the design / builders that worked on the Pratt House and I wanted to a add a few comments about our approach.

    The Pratt House project was/is our first project as a company. Placetailor was founded on the conceptual values of passive design, and we used the established knowladge and documentation of "passivehaus" or "Passive House" to intiate our design thinking. The reason we even choose to compare what we are doing to the standardization of "Passive House" is that the standard has objectives that are necessarily extreme, and they are simply available to compare to. We want our buildings to do what passive house buildings do, because we agree with the ideals of the movement, and are working toward the same end-all result. The project for us, regardless of standards or comparisons was/is meant to be an experiment and a training tool. The overall intent is that we learn something about building science by having a life size model for us to test with. I commend Simon and his family for taking on this challenge.

    I recently attended the Passive House training to ground Placetailor"s decisions on a solid conceptual foundation and to learn from other intelligent people swimming in the Passive House pool.

    In the European countries where Passivehaus is gaining great momentum, there are builders building buildings that could most definitely meet the standard, but are not going for certification, because the construction method and concept is understood as the normal mode of construction. We are testing to see if we can do the same.

    For our second project we are doing a gut renovation called the JP Green House (learn more about it at or I have modeled the project in PHPP, and we are using it as a design/ optimization tool. We decided to use the PHPP to better understand how to build a Passive House. But it isn't until every designer and builder or design/builder in the US and world decides to build this way, that we are going to be successful with our climate goals. It is more realistic that it will catch on as a way of building (certification or not) if it becomes so regular and second nature, that we no longer need to reference the models.

    Thanks for being interested, and keeping a close eye on the proceedings of this great movement.

    Declan B. Keefe

  21. GBA Editor
    Martin Holladay | | #21

    Boston Globe article
    To read a Boston Globe article on article on Simon Hare's house, check out "Home Is Where the Heat Is Off."

Log in or create an account to post a comment.



Recent Questions and Replies

  • |
  • |
  • |
  • |