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Martin’s Pretty Good House Manifesto

Ten principles that green designers and builders need to keep in mind

Posted on Oct 31 2014 by Martin Holladay

One of the presentations I attended at the Passive HouseA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. conference in Portland, Maine, on September 22, 2014 was a session called “Passive House certifiers’ roundtable.” The first speaker on the panel, Tomas O’Leary, explained that he usually charges about $2,200 to certify a residential Passivhaus project. He warned the audience that certification is “quite an effort; don’t underestimate it.”

Tomas advised that anyone interested in certifying their Passivhaus should remember the following important steps:

  • Prepare, collate, and submit the construction and mechanical details.
  • Photograph all critical details.
  • Make sure you get an HRV(HRV). Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor. HRVs recover 50% to 80% of the heat in exhausted air. In hot climates, the function is reversed so that the cooler inside air reduces the temperature of the incoming hot air. commissioningProcess of testing a home after a construction or renovation project to ensure that all of the home's systems are operating correctly and at maximum efficiency. report.
  • Remember that your blower-door testTest used to determine a home’s airtightness: a powerful fan is mounted in an exterior door opening and used to pressurize or depressurize the house. By measuring the force needed to maintain a certain pressure difference, a measure of the home’s airtightness can be determined. Operating the blower door also exaggerates air leakage and permits a weatherization contractor to find and seal those leakage areas. has to be performed twice: under both pressurization and depressurizationSituation that occurs within a house when the indoor air pressure is lower than that outdoors. Exhaust fans, including bath and kitchen fans, or a clothes dryer can cause depressurization, and it may in turn cause back drafting as well as increased levels of radon within the home. conditions.
  • Make sure that you enter the right climate data into PHPP; data from a nearby weather station might not be good enough.
  • Enter the correct U-factors for all of the window components — Uframe, Uedge, Uglass — because each component has to be modeled.
  • The R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. per inch of all relevant materials has to be documented. Listing the R-values is insufficient; each R-value requires a document that justifies the listed value.
  • Document a 360 degree panorama of the shading situation at the building site.

Is each one of these details really essential for determining whether a house can be certified as a Passivhaus? Absolutely.

If you are in any doubt about this issue, remember that one of the cited causes of the famous divorce between the Passivhaus Institut in Germany and Passive House Institute U.S. was a dispute over the details of the certification documents for a house in Canada. The dispute centered on two points: whether the efficiency calculations for a Canadian HRV met the strict efficiency calculation requirements specified by the German institute; and whether an evergreen tree was tall enough to invalidate the shading calculations entered into PHPP.

Getting stuck in the weeds

I admire energy nerds who use THERMUnit of heat equal to 100,000 British thermal units (Btus); commonly used for natural gas. modeling for all kinds of complicated building assemblies. I really do. We can learn a lot from THERM modeling calculations.

I’m grateful that someone has made the calculations to determine that in-betweenie windows perform slightly better than outie windows. Now we know.

I’m also grateful that Stephen Thwaites and Bronwyn Barry are available to explain the subtle differences between the way window U-factors are calculated in Europe and the way they are calculated in North America.

But when I hear lengthy discussions on these issues, I sometimes think we’ve fallen down the rabbit hole. If you are a builder or a designer rather than a building scientist, it may be time to clear the air. It’s sometimes important to balance the recommendations of Passivhaus engineers with some common sense.

Since it’s getting hard to breathe down here, I’ve decided to pop my head out of the rabbit hole and write my Pretty Good House Manifesto. It’s time to identify which features really matter.

1. We need to be humble

I’ve heard Passivhaus builders justify expensive construction details by explaining, “Europeans build houses to last 200 years.”

Well, yes. That’s kind of, sort of, true. But we should remember that 200 years ago, buildings didn’t have central heating, insulation, plumbing, or electrical wiring — so you wouldn’t really want to live in one. At best, a 200-year-old building is kind of like a shipping container. It’s a rigid shell inside of which you can build a modern house.

It’s hard to know what kinds of homes will be desirable in 2214. In 200 years, maybe everyone will be living in electric cars. Or boats. It’s really hard to know whether a 200-year-old Passivhaus building will be considered desirable or a quaint relic in 2214.

My first wife's mother was raised in a solidly built 200-year-old farmhouse near Dingle, Ireland. There were 12 children in the family growing up together in the two-room stone house. The house never had running water or electricity, and it is now being used as a sheep barn — about the only purpose it is fit for.

Thousands of solidly built homes in Detroit have been abandoned, and I suspect that in the coming decades, tens of thousands of homes in Arizona will also be abandoned.

In the U.S., we demolish buildings at a surprisingly fast clip. Nice homes often end up too close to a busy road, or in a neighborhood where no one wants to live.

How many of today's $500,000 Passivhaus homes, each of which was “built for 200 years,” will end up getting an addition? Perhaps a second story? Maybe a remodeled kitchen that needs a bump-out? The fact is, we don’t know.

One thing’s for sure: building a house that is designed to last 200 years is guaranteed to be expensive.

All of these arguments support a building philosophy that Stewart Brand called the “low-road” approach. Sometimes, a small, inexpensive house makes sense.

2. Airtightness matters

The Passivhaus standard may have gone off the rails with its space heating energy budget (15 kwh/m2•year), but they got the airtightness target (0.6 ach50) just about right.

If you want to build a good house, pay attention to airtightness during construction. Once your windows and doors have been installed, perform a blower-door test. Reducing air leaks is the most cost-effective way there is to lower your energy bills.

3. There is nothing wrong with rules of thumb

Study buildings in your climate zone that are attractive, simple, and energy-efficient. Pay attention to their specifications. If possible, talk to the residents and find out whether the buildings are working well.

If you do this, you will develop a gut instinct for what works in your climate zone. Eventually, these instincts can be codified into rules of thumb.

A well-known rule of thumb for cold-climate builders in North America is the 5-10-20-40-60 rule developed by the Building Science Corporation: windows should have a minimum R-value of 5 (equal to a U-factor of 0.20); basement slabs should be insulated to R-10; basement walls should be insulated to R-20; above-grade wall should be insulated to R-40; and attics or roof should be insulated to R-60.

Although some Passivhaus designers ridicule the rule-of-thumb approach as unsophisticated, it works just fine. It gives designers a guideline for good work, but it isn’t set in stone. One of the implied corollaries of this type of rule is that it is somewhat flexible. After all, R-35 walls also work just fine. So does an R-55 attic.

4. We need to include PV

If your building site allows you to build a house with an unshaded south-facing roof, you should include a PV array — especially if you live in an area served by a utility that offers net-metering contracts.

Whether or not your house includes a PV array, designers need to learn how to compare the kilowatt-hours saved by any proposed energy improvement with the number of kilowatt-hours that could be generated by a PV array of the same cost. The calculation really isn’t that difficult; I explained how to do it back in my 2011 article, Net-Zero-Energy versus Passivhaus.

Among the designers who use this method are Marc Rosenbaum, an energy engineer at South Mountain Company, and David Posluszny, a Massachusetts owner/builder.

Here’s an example of how the method works: Posluszny knew that he could save a few kWh each year by upgrading from double-glazed windows to triple-glazed windows. Was the upgrade worth it? It turned out that a few extra PV modules on his roof would generate more energy than the window upgrade would save — for the same investment. So he chose the double-glazed windows.

Of course, performing this type of calculation doesn't obligate the designer to always choose the option that provides the lowest-cost reduction in a home's annual energy budget. In the case of Posluszny's calculation, a designer could justifiably decide to specify triple-glazed windows, based (for example) on improved occupant comfort, even if that decision increased the construction budget. But it's important to make these decisions consciously, with an understanding of the cost and benefits of envelope improvements compared to the cost and benefits of a PV system.

5. We need to size and orient our windows with an eye to comfort and delight, not passive solar gains

Forget about specifying oversized windows for your south elevation. The bigger you make your windows, the more money you are wasting.

In other words, stop thinking that south-facing windows are a good way to heat your house.

Passive solar design principles from the 1970s need to be re-examined in light of an astute analysis made by Gary Proskiw. Proskiw wrote, “The reason the two window upgrades [in his study] fared so poorly, from an economic perspective, is that the space heating loadRate at which heat must be added to a space to maintain a desired temperature. See cooling load. in a NZE [net zeroProducing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines. Calculating net-zero energy can be difficult, particularly in grid-tied renewable energy systems, because of transmission losses in power lines and other considerations. energy] house is very small compared to any other type of house. By adding window area or upgrading window performance, the space heating load is reduced but it is already so small that there is little opportunity for further savings.”

Proskiw concluded that “window area should be limited to that necessary to meet the functional and aesthetic needs of the building.” Isn’t that liberating? Just put in a window that looks good and suits your needs — no bigger. It’s pretty simple.

There is a side benefit to this approach: your house is less likely to overheat during the summer.

Of course, it still makes sense to locate your main rooms on the south side of the house (since people like natural light) and to locate your mudroom, pantry, hallway, and mechanical room on the north side of your house.

6. All-electric homes make sense

As we make the transition to renewable energy, it makes sense to avoid appliances that burn carbon-based fuels like natural gas and propane. All-electric homes make sense — especially if you are able to include a PV array on your roof.

7. Pay attention to domestic hot water and miscellaneous electrical loads

If you have designed a tight, well-insulated home that isn't too big, you will probably find that you are using more energy for domestic hot water than for space heating. To reduce this slice of the energy pie, consider installing a heat-pump water heaterAn appliance that uses an air-source heat pump to heat domestic hot water. Most heat-pump water heaters include an insulated tank equipped with an electric resistance element to provide backup heat whenever hot water demand exceeds the capacity of the heat pump. Since heat-pump water heaters extract heat from the air, they lower the temperature and humidity of the room in which they are installed. and a drainwater heat recovery device. (For more information on this topic, see It’s Not About Space Heating.)

Limit the urge to buy new electrical gadgets for your home. Every time you specify an appliance, look for an Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. label.

Needless to say, it's important to keep incandescent light bulbs out of your house. LED technology has now advanced to the point that you can find an LED lamp for every application.

8. Think twice before purchasing expensive building components

Every generation of designers lusts after a must-have building component. Back when I was building my first house in 1974, it was a Jøtul wood stove. Sure, it was expensive — but it was Scandinavian, and it got a good review in the Whole Earth Catalog.

These days, the must-have building component might be a triple-glazed Zola window from Europe, or a Zehnder HRV with a glycol ground loop.

Here’s the thing: if you find yourself saying, “I know it’s really expensive, but it’s supposed to be the best one on the market,” stop and ask yourself whether you really need it. In another eight years, it’s just going to be an old Jøtul stove, and there will be something else new and shiny that everyone is talking about.

A Pretty Good House can usually be put together with pretty good components.

9. We need to monitor our energy use

For most homeowners, “monitoring energy use” just means keeping track of our electricity, gas, and oil bills. We need to pay attention. Are we using more than our neighbors? Are our bills going up or down?

The nerdier members of our tribe will go a step further, and will install electrical sub-meters, HOBO sensors, and eMonitors. That’s fine. We all learn a lot from paying attention to actual energy use. Energy monitoring provides data, and data matter much more than projections developed by computer modeling programs.

This philosophy — monitor energy use and pay attention to what’s happening — is far better than the usual approach (namely, “I got a plaque to put on my house and now I’m done”).

10. Occupant behavior affects energy bills

While low energy bills are obviously desirable, we need to remember that the construction details of the house don’t tell the whole story. The other side of the coin is occupant behavior.

If you follow your grandmother’s advice — Don’t leave the water running! Turn out the lights when you leave the room! — you’ll save energy. If you build yourself a new 3,000-square-foot Passivhaus and install a big plasma TV and a second refrigerator, on the other hand, your energy bills are going to be higher than mine. For more information on this topic, see Occupant Behavior Makes a Difference.

Some energy-obsessed designers spend weeks trying to track down a European window that will nudge their design from 16 kWh/m2•year to 15 kWh/m2•year — a difference that might save $12 a year in a 2,000 square foot house. When the house is completed, however, it turns out that the teenagers in the family like to take 30-minute showers in the winter, and dry their hair with hair dryers during the summer. At that point, the $50,000 that you invested in European windows starts to look like a bad investment.

If you want to tread lightly on the planet, plan to live in a small house or apartment. Don’t waste energy.

If you follow these simple rules, your lifestyle is probably already greener than that of your wealthy neighbor who just built a brand-new Passivhaus — especially if you bicycle to work.

Martin Holladay’s previous blog: “A New Ground-Mounted Solar Array.”

Click here to follow Martin Holladay on Twitter.


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  1. Nocturnales

1.
Oct 31, 2014 6:18 AM ET

Brilliant
by Dan Kolbert

I'll get out the mimeograph machine and start printing the pamphlets. Allons enfants etc.


2.
Oct 31, 2014 6:26 AM ET

Your #5 about passive solar is simply stupid
by Sonny Chatum

Martin,

5. We need to size and orient our windows with an eye to comfort and delight, not passive solar gains

In a cold climate that gets sunny days in the winter, it has been proven time after time that passive solar contributes a lot to meet required heating capacity. For you to make such a blanket statement, and then support it with an "astute analysis" that actually may have some validity, but only in the very specific example given, is actually hilarious, except for the fact that it is a stupid blanket comment, and except for the fact that a lot of people believe everything you say on this website.

Such a blanket comment about passive solar is stupid because:
--you support it based on an analysis of a net zero house. Net-zero house is meaningless, because those houses can be totally inefficient and still achieve net-zero with vast PV arrays. Net zero has nothing to do with your bad argument.
--a tight, well insulated/oriented house, even a passive house, is well served by properly placed/sized/oriented windows (south facing and otherwise). Peoploe have known this for years. Even you know this. For you to say what you did, has to have some other motive connected to it. The only thing that I have ever been able to figure out that may induce your passive solar ignorance is that you live in Vemont, with no winter sun. That really is a poor excuse for spreading nonsense. Passive solar is better than PV, the bandwagon you have jumped on so hard. Windows are the only real expense, and people have to have them anyway. Then, just like with PV, the sun sends no bill.
--Of course there are some cases where the heating load is already so small that passive solar is not needed! But that is NOT the general rule, except in mild winter climates. I retrofitted my house in a neighborhood with heat pumps running all over the place as soon as the night temperature goes to 45F (October, Zone 4, almost Zone 5). At MY house, although fairly tight and insulated, I would still need heat when temps got not much below that EXCEPT for carefully designed/shaded passive solar. Last year, no heat was turned on at my place until the week before Christmas. Again, heat pumps running elsewhere long before that all around my neighborhood. I could go the entire winter without supplemental heat, IF there were as many sunny days as cloudy days, and if the night temperature never got below about 28F.
---in a well designed house the overheating penalty during shoulder seasons is literally trivial. At my house, it doesn't cost me in shoulder-season air conditioning. The shoulder seasons are the ideal times to open windows anyway.

Your comment is just ludicrous. Maybe you can convince other people otherwise, but even with new construction, it is a crime against nature NOT to use passive solar techniques, unless they are just not available. Finally, I know you will come back with a defense of your comment and, sadly, many will believe. I rarely visit GBA website any more. There is some really good information, here, but there shouldn't be the periodic instances of asininity like your #5.


3.
Oct 31, 2014 6:36 AM ET

Edited Oct 31, 2014 2:29 PM ET.

Response to Sonny Chatum
by Martin Holladay

Sonny,
Every house gets some solar gains through windows, so every house is partially heated by the sun. This has been true ever since window glass was invented.

The question is, how big do you want your south-facing windows to be? I say, they should admit as much light as your family enjoys, but not so much as to create glare and irritation. They should frame the view, but not overwhelm the occupants in a way that limits the sense of coziness that all homes need to provide.

There is no justification for making south-facing windows any larger than required for the principles I have outlined above, as Gary Proskiw explained. Fortunately, the south-facing windows that you decide to include in your house will help heat the house in winter. So relax.

If you want to see the effects of your fenestration decisions, use a good energy modeling program like PHPP. Extensive north-facing glass will increase your space-heating bills, as every designer should know. South-facing glass has the benefit of balancing nighttime heat loss with daytime heat gains, as every designer should also know. But installing huge south-facing windows in hopes that these big areas of glazing will "help heat the house" is misguided.


4.
Oct 31, 2014 7:22 AM ET

Northern Lighting
by Sean Rutledge

Designing solely for energy loads is a mistake (if there is a bit of artist in your heart).

My house had two bedrooms on the north side of the house, lit only by sliding glass door that were shaded and on the NW side of the room. These rooms were dark and uninviting. I put a 4'x6' window facing NE in each room, and was absolutely stunned by the transformation. The outside of the house looked much better too. The driveway approaches from that side of the house, and visitors were greeted by a monolithic, brutalist exterior.

The quality of the light was spectacular and the rooms suddenly became very inviting, almost pulling you inside. The I learned that artists in the past preferred rooms with northern lighting. The sun didn't heat up the room, and the light was consistent throughout the day.

I've made my place a "pretty good house." It's great to know all the best practices and techniques.

But as I was told once, to have style, you should break at least one of the rules.

Thanks again!


5.
Oct 31, 2014 7:32 AM ET

Response to Dan Kolbert
by Martin Holladay

Dan,
I'm glad someone still has a mimeograph machine now that we need one. I hope it is one of the hand-crank, non-electric models.


6.
Oct 31, 2014 7:36 AM ET

Passive Solar
by Jason Hyde, Peterborough 6A

Martin,

I cannot say I entirely agree with the sentiment in your rule 5, though I won't be calling you any names because we disagree.

There is no particular point you make that I feel is inaccurate. However, to me the underlying tone, or takeaway is that passive solar has (or should) be downgraded in priority. Perhaps that is not your intent, but it is how I read it, which I admit is surprising given the source. This, I feel, is a disservice, both to the industry (movement, whatever...), and to your own efforts to educate people.

In fairness, you ended your point advising us to continue following the basic principles of passive solar design, but omitted probably the most important one. Properly designed overhangs. Moreover, you suggest that a side benefit of not worrying about passive solar as a heat source will limit, or help reduce overheating. This is true, strictly speaking - less glazing means less overheating - but again, appropriate overhangs are what prevent it in the first place.

I urge you to include some mention of this important point in your list.

You would be amazed (or perhaps not) how many people I run into that do not realize how ineffective their overhangs are, yet wonder why their home overheats on clear sunny days. These people are not designers, architects, etc, but they are homeowners. If tomorrow we all stopped buying homes with miniscule southern overhangs, people would stop designing them. It's like drinking and driving, we have to keep putting the message out there. Ad nauseum.

The rest of your list I strongly agree with, and thank you for including links to the past articles. I am in the middle of comparing insulation upgrades and was wondering how best to factor PV into the equation.

cheers


7.
Oct 31, 2014 7:47 AM ET

Response to Jason Hyde
by Martin Holladay

Jason,
Regular readers of my articles undoubtedly get tired of the repetitious nature of my writing. To address this problem, I sometimes decide that I don't have to say everything every time I write.

Anyone who hangs out at GBA knows that my nickname is Mr. Overhang. I've been haranguing designers on the topic of roof overhangs for a long time.

You're right, of course. Fortunately, in this article I didn't slip up and mistakenly advise readers that they no longer need roof overhangs. Anyone who wants a refresher course should read the following three articles:

Every House Needs Roof Overhangs

Brick Buildings Need Roof Overhangs

Martin’s Ten Rules of Roof Design


8.
Oct 31, 2014 8:46 AM ET

PGH isn't helpful to consumers
by Scott Tenney

Martin,

I don't disagree with the points you make but PGH is a concept designed by building professionals for building professionals. Unless there are specific standards and an independent certification process, it doesn't really help consumers that much. Most consumers are relatively uninformed and need some sort of official seal of approval to have confidence that a home is relatively energy efficient. If these points were to get worked into a standard - like PHIUS - then it could be really helpful.

Scott Tenney


9.
Oct 31, 2014 8:49 AM ET

Thank You Monsieur Martin
by Bruce Palmer

"Formidable!" as the French say.

From an aspiring owner/builder in zone 4A.


10.
Oct 31, 2014 8:52 AM ET

Edited Oct 31, 2014 8:54 AM ET.

the good guys are....
by aj builder, Upstate NY Zone 6a

Martin, Marc Rosenbaum, and the Maine boys doing PGH oh and Dana Dorset.

And of course Bruce Brownell and even me.

Long live PGH.


11.
Oct 31, 2014 8:54 AM ET

Response to Scott Tenney
by Martin Holladay

Scott,
Plenty of groups and agencies are trying to address your point.

In California, state officials are trying to use Title 24 (the state's building code) and local code officials to achieve your goal, with mixed results.

The Energy Star Homes program is also trying to achieve your goal.

To some extent, RESNET is trying to achieve your goal, by advising anyone who wants one to get a HERS rating.

Several regional green building programs -- including Austin Energy Green Building, the Earthcraft House program, and Build Green New Mexico -- are also trying to achieve your goal.

Do we need a new certification agency to provide Pretty Good House plaques? Let me think for a moment.... Nah.


12.
Oct 31, 2014 9:12 AM ET

Response to Bruce Palmer
by Martin Holladay

Je vous en prie.


13.
Oct 31, 2014 9:18 AM ET

Edited Oct 31, 2014 9:21 AM ET.

What I DO like about the Passive House Approach
by Robert Swinburne

is the focus on simplicity for one thing.
It has taught us that we don't need a complex heating system with pipes full of liquids running everywhere through the house. A minisplit heat pump is an appliance rather than a heating system and as such, is much simpler.
PH also places a very high value on air quality and comfort. Often, the triple glazed windows are important for reasons other than energy use. In Vermont, I often find that people want to be able to go away for a month in the winter and not worry about their plants dying and their pipes freezing if the power goes out. Or they really want that wall of glass facing the amazing view to the North.
PH has shown us that there are excellent ways to get fresh air without simply sucking air (and heat) out of the house with exhaust fans and relying on a leaky shell for makeup air. (Still hearing that you shouldn't build a house too tight from builders)
Granted, we don't need PH to show us these things but PH is good at attracting the media attention enough so that air exchange is on more and more people's "must have" lists.
The biggest benefit of the Passive house approach may be the trickle down effect resulting in, for instance, the Pretty Good House approach.


14.
Oct 31, 2014 9:31 AM ET

Edited Oct 31, 2014 9:44 AM ET.

Response to Robert Swinburne
by Martin Holladay

Robert,
As someone who has been living in a home with a single-point heat source since 1975, and as someone who remembers when David Hansen started installing heat-recovery ventilators in the 1980s, I agree with you that "we don't need a complex heating system" and "there are excellent ways to get fresh air without simply sucking air (and heat) out of the house with exhaust fans and relying on a leaky shell for makeup air."

However, these basic principles were well understood in the 1980s by builders in New England who focused on superinsulated houses -- long before Wolfgang Feist founded the Passivhaus Institut.


15.
Oct 31, 2014 9:31 AM ET

Edited Oct 31, 2014 1:25 PM ET.

The day after I wrote a long
by Lloyd Alter

The day after I wrote a long post saying the exact opposite, I have to admit that the Pretty Good House makes a whole lot of common sense, and is pretty much the approach I took in my recent renovation. And those critics of your position on windows are just wrong; Even the very best window is a very bad wall. Frame a view and be done with it.

In response to your comment below, I don't think there are barricades. There's lots of room for discussion and different views, I happen to really like the ideas of the Pretty Good House, we would all be a lot better if everyone did it.

It's not a war, it's just the difference between a pretty good house and a very good house.


16.
Oct 31, 2014 9:42 AM ET

Response to Lloyd Alter
by Martin Holladay

Lloyd,
I'm glad to hear that you have chosen to align yourself with those of us on the common-sense side of the barricades.

So -- will you be writing another blog to clarify the contradictions?


17.
Oct 31, 2014 9:49 AM ET

Incredible Article
by Stephen E

The passive house is a great teaching tool. It teaches the limits of what's possible. It also teaches what make the most sense for the average home owner and business. The greatest and easiet is the air tightness goal that it sets. The rentals I own I use picture windows where I'm able. Under $200 each and perform better than most hung windows that cost thousands. It provides such an open feeling to the outdoors in zone 5/6. Air tightness makes a world of difference along with a continous air barrier. It takes more time, but not costly at all.

I wish schools would teach this, money management and other real skills. Maybe someday.


18.
Oct 31, 2014 9:55 AM ET

I'm in this camp
by Rachel Wagner

Count me in as one more GBA follower who is encouraged by your blog, Martin. I would only wish that you and the others purveying this approach would have called it "The Good House," as I think that these principles, used in an integrated way, offer a general path to achieve a good house (period). Or maybe, in a nod to 4. Northern Lighting, a path to a "Pretty, Good House." I am happy when the design and building science conversations continue to explore and discuss the integrated nature of design, comfort, energy use, longevity, operation, and resilience. It is important that our community be willing to think critically about our own activities and remember to see the forest for the trees. Thank you Martin, for so often reminding us of this, and for doing so by using history, context, and eloquence.


19.
Oct 31, 2014 10:02 AM ET

Response to Martin
by Robert Swinburne

Wolfgang does make it clear that he is standing on the backs of many before him and has only taken things to the next level - and brought many other people in to help. I do credit him with the excellent marketing skills to bring these things to a larger audience than was reached with "Mother Earth News". (which I grew up reading and I still have a pile of the solar home type books from the 70's and 80's) Passive House has made it easier for us small time architects and builders to convince clients of the importance of air sealing, insulation and air exchange because they've read a "New York Times" article on Passive Houses for instance.
If I get to do a full on Passive House, one of the primary benefits will be the marketing potential for my business.


20.
Oct 31, 2014 10:48 AM ET

You talkin' to me?
by Antonio Oliver

Martin,
So much of your blog resonated with me that I felt like it was an open letter to me. A couple thoughts come to mind. I liked the point you made about tri-pane windows being chosen over PVs. Maybe because it allows comfort to sometimes rule the day over economic optimization. Unfortunately, comfort can be very costly. I mostly like the pretty good house concept, but in my case I know going beyond the PGH concept to get to a desired comfort level in a couple areas will cost me big. One such area is window choice. As long as a person knows this going in, I see nothing wrong with it.

I hear your point about not knowing what someone will want to live in 200 years from now. My house is only just over 60 years old and seems largely inadequate from an energy use standpoint. But you also mentioned that buildings are being demolished at a fast clip in the U.S. I recently read (maybe on the GBA site) that 90% of the homes we will live in 50 years from now have already been built today. I don't know about that, but I can say that where I live 90% of the homes are AT LEAST 50 years old and sadly most of them still have not been upgraded to even the energy code efficiency of today--and many readers of this site find code level efficiency still very inadequate.

Finally, I'm glad to hear I'm not the only person willing to closely track energy use. When we switched out our 60 year old life-supported oil boiler for a gas one last winter, I tracked daily gas use religiously. My wife was so ashamed when I asked a neighbor to take daily readings from our gas meter when we left for a holiday. But tell me how many heating degree days there have been in my neighborhood and I can tell you how much gas I've used and how much it will cost me. Yes, I am a nerd.


21.
Oct 31, 2014 11:56 AM ET

I think you are missing one point.
by Donald Endsley

You did address the point somewhat but I think it needs to be absolutely clear.

Location Matters. A Pretty Good House should be in a Pretty Good Neighborhood. I ain't talking about HOAs, but rather things like walk scores, efficient street layout, availability of transit (and good transit times and frequency) etc... After all most people don't want to cross country ski 5 miles to the post office when it drops to 30 below.


22.
Oct 31, 2014 12:35 PM ET

Edited Oct 31, 2014 12:42 PM ET.

Response to Donald Endsley
by Martin Holladay

Donald,
I'm happy to concede that the ten points in my manifesto aren't a complete list of the features of a good house. Nor was my manifesto intended to be such a list. After all, it's hard to whittle down all the features of a good house to a ten-item list.

As you correctly guessed from the last sentence of my article -- the one about bicycling to work -- I agree with you: transportation issues matter, and location matters. Fortunately, most green advocates agree on this point, so it isn't particularly controversial. (That said, plenty of people who claim to build green homes manage to forget that location matters, so it's good to remind them.)


23.
Oct 31, 2014 1:13 PM ET

In the U.S., we demolish
by George Hawirko

In the U.S., we demolish buildings at a surprisingly fast clip. Nice homes often end up too close to a busy road, or in a neighborhood where no one wants to live. Since the majority of populated areas are near coastlines, Sea Level Rise will have all those OSB constructed homes turn to mush.

11. One thing we all forget or just leave out is maintenance of wood products and the short life of sealed windows. Constant maintenance and replacement will place the Carbon footprint over the top on these building materials. Wood like they used 500 years ago, does not exist, so STOP the comparisons with todays offerings. OSB is not TIMBER.


24.
Oct 31, 2014 1:20 PM ET

Reply to George Hawirko
by Martin Holladay

George,
I'm a little unclear on which of my statements or comparisons you are urging me to stop. I have written many articles warning builders that OSB is inferior to solid boards or plywood, and that OSB doesn't react well to repeated cycles of wetting and drying.


25.
Oct 31, 2014 2:00 PM ET

Edited Oct 31, 2014 2:00 PM ET.

Butt out
by Dan Kolbert

"Do we need a new certification agency to provide Pretty Good House plaques? Let me think for a moment.... Nah."

I've got a sweatshop all set up, cranking out uPVC plaques as we speak. Mind your own damn business.


26.
Oct 31, 2014 2:22 PM ET

Response to Dan Kolbert
by Martin Holladay

Dan,
I'll buy one! As long as I don't have to submit any paperwork...


27.
Oct 31, 2014 2:45 PM ET

Edited Oct 31, 2014 2:46 PM ET.

Thanks to all
by Peter Hastings

Thank you to all who have contributed to this long-running discussion - culminating in this succinct and insightful call-to-arms. I would quibble with Lemma 5 and suggest "...not just for passive solar gains."
Lemma 7 - Are there drainwater heat recovery systems which will work in single storey dwellings ?

Mr Alter's comment (in #15) that "the very best window is a very bad wall" hides the deeper truth that "any sort of wall makes a completely rubbish window" Windows are needed for all sorts of reasons and the size of them can, with a good architect, combine desired views and modest area. I have seen stunning examples in mountainous coastal areas where the window is a 'letter-slot' at eye-level framing islands, horizon and enough sky to satisfy any Winslow Homer fan.


28.
Oct 31, 2014 3:37 PM ET

For Peter Hastings
by Dana Dorsett

"Are there drainwater heat recovery systems which will work in single storey dwellings ?"

https://ecodrain.ca/en/products/

https://ecodrain.ca/media/products/ecodrain-installation-manual.pdf

They're on about Revision 3 of the design.

I'm not exactly sure what it's performance specs are, as they do not appear on Natural Resources Canada's third-party tested apples-to-apples listing tested at a specified flow & water temp. I'm sure it's WAY better than nothing, but probably less than what a 55" long gravity-film type vertical heat exchanger delivers (which would be between 45-65% heat recovery under the standard temp & flow conditions depending on diameter.)

Could be better than 35% though, maybe even north of 40%, but you'd have to bug them for some test data, since they're apparently not participating in the NRCAN standard-test comparison game, since they own the entire market for horizontal heat exchangers at this point.

http://oee.nrcan.gc.ca/pml-lmp/index.cfm?language_langue=en&action=app.s...


29.
Oct 31, 2014 4:15 PM ET

The only paperwork required
by Dan Kolbert

Is a Jackson.


30.
Oct 31, 2014 5:23 PM ET

South Facing Glass
by Daniel Ernst

Thanks, Martin. It's always a pleasure reading your blogs.

Regarding the pushback on south facing glass, the last BSI article from Lstiburek makes the same point.

http://www.buildingscience.com/documents/insights/bsi-081-zeroing-in/

"Here goes. Don’t bother with the passive solar. Your house will overheat in the winter. Yes, you heard that right. Even in Chicago. Are you listening Passive House? You should go with very, very low SHGC’s, around 0.2, in your glazing. If this sounds familiar to those of you who are as old as me it should. We were here in the late 1970’s when “mass and glass” took on “super-insulated”. Super-insulated won. And super-insulated won with lousy windows compared to what we have today. What are you folks thinking? Today’s “ultra-efficient” crushes the old “super-insulated” and you want to collect solar energy? Leave that to the PV."


31.
Oct 31, 2014 7:19 PM ET

overheating
by stephen sheehy

Anyone have an opinion as to what constitutes overheating? My existing house has a long wall of southfacing windows that warm the entire downstairs in winter. It screws up the radiant heat, but if the space gets up to 77°, that's OK by me. I can take my sweater off. In summer, a big river birch in front of the windows shades them pretty well. If it gets too warm, we open the windows.

My new house will have a pretty big expanse of glass on the south side, in part because we want the light and also because we'll have a nice view. I'm willing to chance winter overheating. Of course, we're in Maine, where being too warm is a nice change.


32.
Oct 31, 2014 8:33 PM ET

Edited Nov 20, 2014 11:35 AM ET.

PV
by C. B.

If you don't have a good south-facing roof or trees shading your south-facing roof, you should consider:
http://gmisolar.com/solar-panel-tracking-systems-pole-mounted-solar/
I am currently putting one in at my house. A solar PV array on a steel pole with the dual-axis rotation to follow the sun will maximize the electrical power generation. While the size of the array is more than is needed for lighting/heating/cooling the house, its output is also planned to provide power to fully-electric (ex. Ford Focus Electric) or plug-in hybrid electric (ex. Ford C-Max Energi) vehicles. The goal is not just be a carbon-free house but a carbon-free household.

gmi-solar_star-tracker.jpg


33.
Oct 31, 2014 9:30 PM ET

Edited Oct 31, 2014 9:31 PM ET.

Count me out
by Malcolm Taylor

No charismatic leader to quote.
No cache so you can boast about your green cred at parties.
No claim to save the earth.
No rigid criteria to blame the shortcomings of your house on.
No certification or plaque - despite Dan Kolbert's hollow promises.

It sounds too much like a common sense approach thought up by reasonable adults for reasonable adults. I'm out.


34.
Oct 31, 2014 10:49 PM ET

A Pretty Good Manifesto
by w d

Martin,

... spreading non-sense, ludicrous, asininity, ... Have you ever considered doing charity work as the target in a no-holds-barred name calling contest?

Anyway, it's a pretty good Manifesto and it's a good lesson in common sense.

My observations:

1) (Point 4). It's natural to see PV in the picture. It works in every climate zone with varying effectiveness. It produces energy that is fungible. It's year-round. It's carbon beneficial and that's a low profile yet key element in the Manifesto (n'est pas?) In our neighborhood PV is not encouraged and our lot is non-optimal or I might have some panels now. But, there are other projects that produce similar benefits. Normally, I'd expect comparisons to be made to the best available technology. In our climate (Chicago, zone 5A - 6B) and at our house I've found reducing solar gain (in summer only) to be more impactful in $ and in carbon and without tax credits or "programs". My rough calculations show the cost of PV of $1,000 for saving 320 kwh/year would have to be cut in half again before performing as well. Should we stick with Point 4 regardless of the comparative economics?

2) (Point 5). Passive Solar. Mr. Chatum makes a good point. I completely missed it. I think I read in the missing parts as though it were written :" ... we need to size and orient our windows with an eye to comfort and delight (as well as to manage solar gain and shading)".

3) (Point 6). All-electric Homes. If the objective is to reduce carbon, an all electric house makes sense, given PV or WIND supply. However, if economics are still relevant, all energy sources are in the discussion. No one in our neighborhood is likely to shut off their natural gas just to go all electric.

4) Nicknames. Beware of nicknames like "Mr. Overhang". Too much opportunity for unfortunate miss-readings.

5) (Possible Point 11). Something Old, Something New.
We should address buildings of all types, not just new residential construction. With so many existing buildings, greater gains are often with projects at those buildings. Not only are older buildings less efficient, there are just so many of them.

The PH phenomenon is instructive but I wouldn't spend anything just for a certification. I do, however, respect those who seek such recognition and who celebrate it once achieved.


35.
Nov 1, 2014 12:04 AM ET

Another really good article
by Gordon Taylor

Another really good article by Martin. But I have a question about LED lights. Martin, you urge people to put LEDs in all our fixtures to save energy. And I too love LEDs. But doesn't this ignore the fact that LEDs really don't survive very long in enclosed fixtures? Cree doesn't guarantee their bulbs in enclosed fixtures, and I've found very few other manufacturers that do. LEDs produce very little heat, but they are also far more sensitive to heat than tungsten filaments. If you go to Home Depot, for example, and look at customer comments regarding Cree bulbs, you see a surprising number of disgruntled consumers. A typical comment is, "It worked great for two days, and then--nothing." Somebody really needs to do an article surveying the survivability of LED bulbs in enclosed fixtures. I really wish that Martin H. or one of your crack investigators would take this on. I hope someone will respond to this.


36.
Nov 1, 2014 3:35 AM ET

Response to Stephen Sheehy (Comment #31)
by Martin Holladay

Stephen,
You have told us that your house has a long wall of south-facing glazing; that the solar heat gain on sunny winter days is appreciated; and that when necessary, any overheating is easily handled by opening the windows.

I'm concluding that you are happy with the amount of south-facing glazing in your house. If you are happy, all is well. You appear to be abiding by Gary Proskiw's recommendations -- that your south glazing should "meet the functional and aesthetic needs of the building.”

If you were still at the design stage, however, you might want to perform a more subtle analysis.

Let's say that your house now has 100 square feet of south-facing glazing. (We'll call that Option 1). At the design stage, you might consider another option -- say, one with only 50 square feet of south-facing glazing. (We'll call that Option 2).

A good modeling program might tell you that (depending on what type of glazing you specified) that Option 2 saves energy compared to Option 1. If that's true, you might consider Option 2 -- less glazing -- as long as your family wouldn't miss the summer sunshine that floods your house.

Then you might consider two other options: let's call them Option 1A and Option 2A. These options would be the same as the other two, only with upgraded glazing (maybe moving from double to triple glazing).

Perhaps with triple glazing, you are able to show that the option with lots of glass -- Option 1A -- saves a bit of energy on an annual basis compared to Option 2A (the one with less glazing area). If that's the case, you might want to use Gary Proskiw's method, and determine whether the energy savings associated with the additional windows is worth the cost of the extra windows (especially when compared to an investment in PV). You just might find that the extra 50 square feet of glazing aren't a great investment. Then you could decide what to do.

But -- if some of your family members have Seasonal Affect Disorder, or you like to grow banana trees, this analysis doesn't matter. You may want to maximize the amount of south-facing glazing in your house, just because it brings your family delight. If that's the case, go for it -- because that's what matters.


37.
Nov 1, 2014 3:43 AM ET

Edited Nov 1, 2014 4:20 AM ET.

Response to C.B. (Comment #32)
by Martin Holladay

C.B.,
For a discussion of the advantages and disadvantages of PV trackers, you might want to look at the comments posted on my article from last week (A New Ground-Mounted Solar Array).

In Comment #41 on that page, Derek Roff discussed his tracker. He wrote, "Downsides include greater cost and vastly greater maintenance/reliability concerns. Our experience includes lots of repair calls for the trackers. So far, all under warranty."


38.
Nov 1, 2014 3:47 AM ET

Edited Nov 1, 2014 4:21 AM ET.

On Malcolm Taylor's lament (Comment #33)
by Martin Holladay

Malcolm,
You complained, "No certification or plaque - despite Dan Kolbert's hollow promises."

As far as I understand, Dan's promises aren't hollow. Only the PVC plaques are hollow.

However, I think that Dan is considering an upgraded plaque for a small additional charge. It would still be PVC, but the hollow plaque will be foam-filled. Stay tuned for more details.


39.
Nov 1, 2014 4:00 AM ET

Edited Nov 1, 2014 4:05 AM ET.

Response to W.D. (Comment #34)
by Martin Holladay

W.D.,
I'm a little scared. I wrote a ten-point manifesto as a reaction against a rigid program with strict rules. Now I'm being asked to interpret my ten points, as if I have suggested newer, stricter rules.

In case I wasn't clear on this point: The best way to interpret my suggestions is with good old common sense. (It hasn't gone extinct yet, has it?)

In my article, I suggested that anyone (a) who had a house with an unshaded south-facing roof, and (b) who lived somewhere where the local utility offered net-metering contracts, should consider installing a PV array. Now you tell me that you live in a neighborhood that isn't favorable for PV, and that you have identified other, easier measures that save more energy for a smaller investment. So what should you do?

At the risk of stating the obvious, W.D., you should start with the measures that save more energy for a smaller investment.

I suggested that south-facing windows be planned so that they provide comfort and delight. You pointed out that we should consider solar gain and shading. I agree, of course. That's how we achieve comfort, isn't it? Otherwise, any unshaded south-facing windows could cause overheating, especially if they are large. And overheating isn't comfortable.

I agree that anyone with an existing cold-climate house that is heated by natural gas has a strong incentive to keep his current heating fuel -- especially if we're talking about a working-class family without savings. I understand that. (Again, I'm applying common sense.) But if a family is planning to build a new custom house, they have the luxury of considering different types of heating fuels. In that case, they should probably consider designing an all-electric house.

In your last point, you wanted to remind readers that upgrading existing buildings often makes more sense than building a new custom home. I certainly agree. That thought was expressed in the last three sentences of my article, where I wrote, "If you want to tread lightly on the planet, plan to live in a small house or apartment. Don’t waste energy. If you follow these simple rules, your lifestyle is probably already greener than that of your wealthy neighbor who just built a brand-new Passivhaus — especially if you bicycle to work."


40.
Nov 1, 2014 4:16 AM ET

Edited Nov 1, 2014 4:17 AM ET.

Response to Gordon Taylor (Comment #35)
by Martin Holladay

Gordon,
You're right that LEDs can overheat in enclosed fixtures. The word "lamp" can be ambiguous -- so when I wrote, "You can find an LED lamp for every application," it's possible that some readers misunderstood.

For readers who are used to lighting jargon, it might have been clearer if I had written, "You can find an LED luminaire for every application."

In any case, here's my point: if you are planning a new house, go to a good lighting showroom and ask about LED options.

If you are retrofitting an LED bulb in an existing fixture, on the other hand, be cautious. Installing an LED bulb into an existing enclosed fixture might not be appropriate.


41.
Nov 1, 2014 4:57 AM ET

Certifiable
by Steve P

Thanks for an interesting column. I am merely an interested layman with a sensitivity toward good construction. I have owned more homes than average, on (so far) three continents, so I have been exposed to quite a variety of building techniques and seen my fair share of mistakes.

I am reminded of various ISO certification schemes in industry where many businesses lost sight of customers and products in the drive to comply with some "standard". Many of them (both businesses and schemes) no longer exist. One has to wonder if there is any real relevance beyond some trickle-down effect once a practice is found to be either a "no-brainer" or conversely idiotic.

It sounds like the 200-year-old Dingle stone cottage is still standing and in use, so that's quite testament to local builders using indigenous materials. Pretty good bang for the buck. Passivehuas? I'm not at all certain. I don't think I've ever seen a "real" one - just read about them. What percentage of new-home construction would meet a similar standard? I go to Germany a few times a year but the new houses I see would be unlikely to meet the standard, I suspect. I often see huge houses built with huge budgets and all the latest tech but with so many show-off windows they may as well have skipped the insulation. Because efficient (in both energy use and construction costs) houses often look a bit poky, actually.


42.
Nov 1, 2014 5:35 AM ET

Response to Steve P
by Martin Holladay

Steve,
Q. "What percentage of new-home construction would meet a similar standard?"

A. As far as I know, there are still fewer than 200 Passivhaus buildings in the U.S. -- so this type of building represents an inconsequential (far less that 1%) share of new construction in the U.S.

Q. "I go to Germany a few times a year but the new houses I see would be unlikely to meet the standard, I suspect."

A. While most regions of Germany haven't yet made the Passivhaus standard mandatory for new construction, the German building codes are ratcheting up, and are getting close in some regions. Austria may be even further ahead than Germany in this regard. According to Wolfgang Feist, "The EU has said that from 2020, the national governments in Europe are required to establish new construction standards [building codes] with energy performance levels that are as low as the Passivhaus standard."


43.
Nov 1, 2014 10:30 AM ET

EU standards
by Steve P

Thanks Martin. I'm currently involved on a small renovation in the UK and I must say I will be amazed if that EU country achieves anything similar to Canada's R2000 standards (which I built to in 1990) by 2020. Currently, levels of insulation are being upgraded, but only where they do not (much) affect building practices. So lofts (attics) get extra insulation depths but walls are the same as 25 years ago - sometimes uninsulated. Passivhaus-style structures exist, but which would never meet the standard even in this (southern UK) temperate climate. Thermal bridging and vapour control are ignored by most builders entirely. In other words, they change things that require few changes in traditional construction techniques, instead of doing the things that provide the best return on investment. No doubt this is partly due to the difficulty in changing trade practices.

When I think of my travels in Europe, with very high-quality Scandinavian homes (expensive heating) to southern European homes with little attention paid to energy use (Mediterranean climate) it is very difficult to see how such a "dictatorship" of standards could be written - let alone enforced. But if anyone could do it, it would be Austria (population 8 million - about that of metropolitan London).


44.
Nov 1, 2014 5:53 PM ET

EU Standards
by Peter Hastings

If the standard is written based on energy performance then the various national governments within the EU will be able to tailor their own building codes to match local climate conditions. Those with a benign climate will need less energy for heating and cooling (and can use the allowed surplus for cooking and washing) while those with more challenging climates will oblige their citizens (via punitive fines) to eat raw food and smell a bit. It's all perfectly logical...


45.
Nov 2, 2014 12:23 PM ET

Response to Steve P, comment #43
by James Morgan

And yet the per capita annual energy consumption of the Brits is way lower than that of the Germans. And lower than most of the rest Europe too. Go figure.


46.
Nov 2, 2014 5:49 PM ET

Edited Nov 2, 2014 5:53 PM ET.

PGH = NZE?
by Dwight Harris

Is it safe to say that "Pretty Good House" is synonymous with the DOE's "Net Zero Ready?" The principles seem the same. Plan for solar, minimize loads, and aim for a low, but not crazy extreme HERS ratings (40's is good enough before solar).
[edit: typo]


47.
Nov 2, 2014 10:32 PM ET

Pretty Good Post
by Bronwyn Barry

Thanks for the kind mention, Martin. This is a great post and I can't disagree majorly with any of its 'rules of thumb.' PGH is essentially a good way to design and build homes in a cold climate. I find much to support and, based on the Passive House projects I visited in Maine, I see much more agreement and alignment between PGH and Passive House than is possibly acknowledged here.

It's inspiring to see how many GBA articles have been stimulated by or are referencing the NAPHN14 Conference. I saw great evidence of the alignment and overlaps between PGH and Passive House at NAPHN14. I also had the honor of learning about how PGH evolved and had fun meeting a few of its Maine proponents. (Thanks for the beer, Dan, and for the fantastic Haus Party, Steve.) It looks like the experience of this group of builders all gathering together to figure out exactly what is working for buildings in this region will help everyone build better buildings. I do have a sneaky suspicion that PGH builders will all end up building Passive House projects sooner or later though. (Once you hit 0.6ach, the rest gets pretty easy.) With the support, supplies and technical skills already available to you all in the North East, it looks like you just need a local window manufacturer to produce a well insulated frame with good IGU’s and you’re there? Then, for those odd projects that simply won’t fit into the ‘rule of thumb’ box, the PHPP can be used to help you figure out exactly what is needed to build a Pretty Good Passive House. (I’m doing exactly that for my projects here in California.)


48.
Nov 3, 2014 6:03 AM ET

Response to Dwight Harris (Comment #46)
by Martin Holladay

Dwight,
Q. "Is it safe to say that Pretty Good House is synonymous with the DOE's Net Zero Ready? The principles seem the same."

A. I am not familiar with DOE's Net Zero Ready program, but it wouldn't surprise me if there were substantial overlap between the principles of that program and the ideas in my article. The basic idea behind Pretty Good House design is common sense. There is no list of rules, so the Pretty Good House concept is never going to align perfectly with any program that includes a list of rules.

I make no claim of originality. All of my ideas are borrowed. Hopefully, common sense is still common enough that it is widely distributed in the population, existing happily without authorship.


49.
Nov 3, 2014 6:09 AM ET

Edited Nov 3, 2014 6:30 AM ET.

Response to Bronwyn Barry (Comment #47)
by Martin Holladay

Bronwyn,
Thanks for your kind words. I suspect, however, that you give too much credence to the idea that Maine builders who complete a Pretty Good House have almost built a Passivhaus.

You wrote, "I do have a sneaking suspicion that PGH builders will all end up building Passive House projects sooner or later though. (Once you hit 0.6ach, the rest gets pretty easy.) With the support, supplies and technical skills already available to you all in the Northeast, it looks like you just need a local window manufacturer to produce a well insulated frame with good IGU’s and you’re there?"

That may be true in the areas of California where you work, but it isn't true in Maine. The Passivhaus projects that have been built so far in Maine differ in many substantial ways from the type of house I describe in this article: they end up with very high R-values in the foundation and roof; they usually require very expensive windows; they usually end up with very expensive ventilation systems; and they usually require the assistance of a fairly expensive Passivhaus consultant.

Finally, the idea of comparing the kWh savings of a proposed energy improvement with the kWh savings that would come from a PV system of the same cost is totally foreign to the Passivhaus method. When I have suggested this approach to Passivhaus designers, my suggestion has been met with hostility and derision.


50.
Nov 3, 2014 6:34 AM ET

R 5 Windows
by Tim Naugler

Just curious what you might suggest Martin and others for R 5 windows.
I'm a builder in New Brunswick Canada, who has built both PGH (before it had it's name) and Passive House both have their Merritt and can be cost effective immediately for the client, But from my current experience our clients like that their is some sort of target or 3rd party verification if desired. Anyway not the point of my post. I was curious to learn from the GBA people what windows they are using in a PGH scenario?

In my case on two PGH projects we have used JeldWen Casement vynal Tripple Glazed with Cardinal glass with 2 coats of the 180 low e. The glass does a good job with keeping the comfort level up and condensation away however in the house without a forced air heating system (they use point source heat both a wood stove and minisplits)we are having problems with the frames condensating when the weather get's really cold.
Other than that the PGH are preforming better than modeled and the clients are super happy!

On our passive House projects we have used UPVC Internorm ThermoPassiv and UPVC Klearwall and have not had these issues. (both of which were very well priced for the performance and quality if you are aiming to certify a PH)
Just wondering if i'm missing a option for the PGH windows where we wont have these window sweating problems without a heating vent below each window?

Keep up the good work Martin!


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