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The ‘Low-Hanging Fruit’ Fallacy

Small weatherization jobs that aim to pick the ‘low-hanging fruit’ seldom deliver remarkable results

This graph tries to show how utility executives think about residential energy retrofit work. The horizontal axis shows the number of energy upgrade measures that are implemented — for example, attic air sealing, attic insulation, a new furnace, or a new air conditioner. The vertical axis shows energy savings. Unfortunately, the results of real home performance jobs usually don't follow this curve.
Image Credit: Nate Adams

First, a definition. The phrase “energy efficiency programs” (or just “programs”) refers to any utility-funded or state-funded program that offers homeowners a rebate, incentive, or inexpensive financing to make energy efficiency upgrades in their homes.

We don’t need no stinking programs

It’s important to note that comprehensive home performance retrofits do not require programs. My company (Energy Smart) is proving that right now.

We are selling $15,000 to $40,000 jobs involving both shell and HVAC measures with no program involvement and no special financing, in an area of the country with low housing costs and low utility costs.

Like a bumblebee, a physicist didn’t tell us that we couldn’t fly, so we just did.

But programs can help

Programs could help accelerate market transformation. Rather than dictating details and constraining trades, properly designed and implemented incentive programs can help start and accelerate markets.

Low-hanging fruit is poisoned

A major current problem with existing programs is that they encourage chasing low-hanging fruit. Programs tend to think that individual measures save energy predictably and repeatably, so low-hanging fruit is a good strategy. They do not.

Every situation is unique, and bringing things into balance is different every time. Programs are designed as if the best opportunity is the first, “easy pickings” measures.

We need to go deeper to truly achieve good home performance and energy savings. We have to get pretty good control over heat, air, and moisture flows within a home. No single measure can do this. It takes a mixture of well-thought-out improvements to get there. In our experience, making a few small changes often has disappointing results or unintended consequences.

For now, this concept is largely based on anecdotes. But it meshes with what Lew Harriman, Rick Chitwood, Mike MacFarland, Dan Perunko, and Gavin Healy have found and reported in the book, Measured Home Performance. MacFarland has so much confidence in his energy predictions that he guarantees total energy bills or he pays the difference. He can predict monthly bills within a few bucks a month. His jobs aren’t small, though; the illustrations will show why. It also jives with John Proctor’s study of four homes in California. So please bear with the rather conceptual ideas here; in time, there should be more data to support this hypothesis.

We’ve come up with a way of visualizing “low-hanging fruit thinking” vs. “comprehensive home performance thinking.”

Let’s look at the graph at the top of the page. The X axis shows the number of energy upgrade measures that are implemented (or investments or money spent). For example, attic air sealing, attic insulation, a new furnace, or a new air conditioner would all be things that would go on there.

The Y axis displays the results — for example, energy savings or solved client problems.

The curve on the graph shows how people think that energy savings opportunities look — a game of quickly diminishing returns. This is intuitively how it seems like it should work. A few of the changes should have the largest effect.

Snow tire thinking

Would you buy just one snow tire? Two might help, but most would agree four is really best. The benefit of one is basically zilch, and actually is likely to hurt you when you wreck the car. The real benefit occurs when you reach four. Then you have true control over the car’s movement, just as when home performance work aims to control heat, air, and moisture movement within a home.

In buildings, serious energy savings occur when out-of-balance systems are brought into balance. The whole building is the system — not just the insulation or furnace. This doesn’t always require spending more money, but it requires thinking systemically rather than prescriptively. So the graph at the top of the page is not as true as we might think.

Here is how the comprehensive energy efficiency success/opportunity curve actually looks.

Returns don’t start to occur until you get deep enough to start correcting imbalances.

In systems thinking, everything is interconnected

Energy efficiency requires design that is specific to the situation. Everything has to work together, solving specific and unique problems. The more things are brought into balance, the greater efficiency is realized.

Another way to look at it is like losing weight and getting healthy. If you watch what you eat two days a week, but pig out the rest of the time and don’t exercise, can you expect results? Of course not. Truly improving health requires a tailored mix of diet and exercise. Training to run a half marathon would likely land in the middle of the curve, where four investments leads to six benefits.

Unfortunately people don’t realize that when you just do one thing and results fail, it is a failure of the system design. You can’t replace one snow tire; it is part of a system. You can’t just diet for two days a week; there must be a system of diet and exercise to see results.

Interaction examples

In a home, if you just air seal the attic, you may drive up energy costs because the warm attic is no longer a buffer. If you just insulate, mold is likely when the temperature gets low enough for condensation and moisture escapes from inside the house. Put in an efficient furnace in a crappy building envelope, and you will still have uncomfortable clients. Air seal the basement but not the attic, and you could cause backdrafting. Insulate and air seal without downsizing the HVAC system, and you could make an already cold addition colder because the furnace runs less, since it is now wildly oversized. Install can lights in a house with a kneewall attic, and you could cause ice damming and basement flooding.

Everything is interconnected. There is no low-hanging fruit. It’s a system.

To recap, in the low-hanging fruit thinking, the best investment is small (somewhere near number 2 on the X axis). Ironically, in reality that is the absolute worst investment. This size job offers poor results, unintended consequences, and low contractor profitability. These are the jobs that killed my company. In reality, the best investment is the incremental investment made after the low-hanging fruit investment — when you move from 3 to 5 or 6 on the X axis.

Chasing low-hanging fruit is a major cause of poor realization rates

See the problem? Red “low-hanging fruit” thinking causes investment to stop well before Blue goes vertical. A small job is a much easier sale; it can be made in one visit. The contractor and the program walk away happy, claiming the red “win” — except the consumer is left to experience the blue outcome. The truth of this is supported by both low average job size, and the fact that these programs’ own M&V studies show dismal realization rates.

Typically our jobs are three to four times the size of most jobs that seek incentives or rebates from a program. Our jobs are more comprehensive, predict savings with much higher precision, and (most importantly) result in happy consumers. Programs would be better if they encouraged results like this.

Chasing low-hanging fruit is a dead end

Market transformation requires happy consumers. It requires people to get what they paid for — not half measures delivering quarter results. If the home performance industry continues to chase low-hanging fruit, we are unlikely to achieve remarkable results and market transformation.

[Editor’s note: The next article in this series is Hard Truths of Home Performance.]

Nate Adams is a recovering insulation contractor turned Home Performance consultant. His company, Energy Smart Home Performance, is located in Mantua, Ohio. Using a comprehensive design approach, he fixes client woes with a market-driven process that he hopes will lead to market transformation for our industry.


  1. woodgeek68 | | #1

    Couldn't agree more.
    Brilliant article that totally reflects my (amateur) experience with one home (mine).

    I DIY retrofit my house, airsealing an attic and tuck under garage over the course of a couple years. Comfort got worse before it got better, and the $$ savings were small, and then surged as I got toward the end, ultimately, I DIY'ed my BTU heating loads down 30-35%.

    Then I called in the pros to tackle the more difficult end of the project.....densepacking my (drywalled over) sills and rimjoists, blowing cellulose to bring my attic up to R-50, targeted airsealing, etc. A $5k job. They reduced my BTU loads by 15% of original (or about 22% reduction from what they started with). IOW, they achieved about half what I got DIY using <$300 in materials and ~50 hours of targeted labor, suggesting the curve bends over again.

    I am a fan of MacFarlane....and put one of his EDIDS on my ASHP last spring....I think it will save me 25% on my heating bill.

  2. kevin_in_denver | | #2

    Low Hanging Fruit Do Exist
    Nate, Your analysis is excellent.

    Some control problems can be considered as true low hanging fruit, and oftentimes the average heating/cooling tech can't figure them out.

    A classic one in Denver is the house with both a swamp cooler and conventional air conditioning. Obviously they shouldn't be operated at the same time.

    Cold air intermittently blowing on a thermostat is another example. Homeowners with double hung windows sometimes don't realize when that upper sash has slipped down.

    In the multifamily arena, I find really juicy ones in over half the buildings I inspect. Even so, I was unable to sustain a viable one-man business out of easy fixes:

  3. Brent_Eubanks | | #3

    whence the low hanging fruit
    I absolutely agree with your main points, that a building must be approached as a system, and that fixation on low-hanging fruit is misleading. Focusing on "low hanging fruit" is is another way of saying "we're fixated on a quick payback with minimal investment", which is a much more credible framing of that approach.

    That said, I have to wonder where this particular obsession came from in the first place - is it just a reflection of the common desire to make a quick buck/savings, or is there more going on?

    In my work as a commissioning agent, I have seen quite a bit of legitimately low-hanging fruit (or even fruit rotting on the ground). This has been in commercial buildings, and has almost always been a problem associated with either controls or with grossly deferred maintenance (leaking valves, broken economizers, etc). The energy savings associated with finding and fixing a leaking heating valve on a 50,000 CFM AHU is tremendous, and the fix itself doesn't cost very much - usually the investigation that identifies the problem cost more than the work to actually fix it.

    Two thoughts come out of this:

    1. The perception that low-hanging fruit is commonly available may arise from people with experience on commercial buildings that are more mechanically complex and thus have more points of potential major failure. Homes typically don't have complex controls, economizers, etc. If people with big-building experience are designing these programs aimed at homeowners and small contractors, that could be a big part of the disconnect right there.

    2. There is a lot of savings to be had, in many cases, by correcting deferred or deficient maintenance. Those opportunities exist for sure in the commercial/institutional sector; they are less common but obviously still exist in the residential sector. The problem is that many of these programs (residential and commercial both) fail to acknowledge the fact that, really, they are just subsidizing deferred maintenance. And this leads to a wholly inappropriate focus on new equipment and upgrades, rather than on investigation and correction of existing failures.

    From the commercial side, the potential energy savings are in many cases large enough to provide a very good ROI, if the investigator is correctly focused on identifying these opportunities. The major failure of those programs, IMO, is that they do not encourage this particular focus. A program that actually just focused on identifying and fixing equipment failures would probably cost a lot less than, and be as effective as, many of these utility-subsidized RCx programs.

    From the residential side, this is a much tougher sell. The energy savings from a single home will not pay for the time of an experienced energy professional or contractor. And because every home is different, each one has to be tackled as a new project. This, I am sure, is a large part of the reason that these programs focus on the installation of new equipment; otherwise, no one would make any money at all. Unfortunately, as you say, the design of these programs are such that they encourage exactly the non-optimal amount of investment.

    I do think that programs focused on low hanging fruit are valuable and have their place, and can save a lot of energy. But they need to be designed around the realization that what they are really doing is finding and fixing problems with existing equipment. They may bring the building up to its potential level of performance or its as-new performance. They will not, and should not attempt to, dramatically improve on that performance - not at the investment level they are targeting.
    For commercially energy efficiency, as I said, the savings can in many cases support the cost of the investigation and the repairs.
    For residential energy efficiency, that is almost never the case and the program must be structured to reflect that reality. Probably such a program would be most useful if it just paid outright for the investigation and for a minimum (say, $1000 max) of repairs, rather than trying to goose "the market incentives" with subsidies. Savings would be modest but real (on average, not for every building), and project throughput would be very high, without incentivizing the sale of poorly-conceived "upgrades" and without any cost to the homeowner.
    But that would be socialism, I guess.

  4. GBA Editor
    Martin Holladay | | #4

    Not every house has low-hanging fruit
    First, it's important to get this statement out of the way: Not every house has low-hanging fruit. OK?

    But a lot of them do, especially in neighborhoods with old houses. Can we all (at least) agree that big holes in the thermal envelope represent low-hanging fruit?

    You know what I'm talking about, Nate: The basement window pane that has been replaced with cardboard or luaun plywood, with a hole in the middle for the cat to get out.

    The chase around the brick chimney that goes clear from the attic to the basement.

    The attic access hatch that consists of uninsulated 1/2-inch plywood with no weatherstripping.

    Come on, Nate. You've been in a few attics and basements. The attics and basements in Ohio can't be that different from ours in Vermont.

    Tell me you've seen a few cat-sized holes in your day. I know you have. That fruit hangs very, very low.

  5. Expert Member
    Dana Dorsett | | #5

    Yep, a lot of existing houses have low hanging fruit, and lack of air-sealing is #1.

    I plugged a heluva lot of holes in my house without seeming to make a difference, before I found the 4" x 12 foot hole in the framing in a tight spot behind an attic kneewall where the roof transitioned over a ventilated porch roof. The foam guys in insulated between the rafters, but neglected to seal the 4" gap between the beams on this bizarrely framed piece of 1920s hip-roofed bungalow-ness. If the original builders hadn't built the porch roof overlapping the main roof (or had removed the decking at the overlap) it would have been more obvious.

    Strangely, fixing that FOUR SQUARE FOOT hole made a noticeable difference on the whole house infiltration rates and wintertime relative humidity- go figure! It would have been dead easy to find that hole with a blower door, but it took a real contortionist act to get in close enough to even see it for what it was, let alone treat it.

  6. Tedkidd | | #6

    What's it worth? What's it cost?

    Appeal to faith? Bandwagon fallacy? Circular reasoning? Loaded questions? Meaningless questions? Conventional Wisdom? Not sure which best describes your comment.

    If you have an obvious hole in your home that you are not smart enough to plug yourself, what else do you have that needs to be addressed? Are you really going to hire me to come to your home and be satisfied if I charge you for simply running around and fixing the obvious things, still leaving you with a poorly performing home?

    Think that's not what usually happens? Come see some houses with me, I'll show you that's what USUALLY happens. Here's one documented example:
    Here's the video:

    And a huge part of what we do isn't just fixing homes, it's helping people avoid colossal mistakes going forward.We are regularly recommending the replacement of equipment that is brand new. How would you feel if you were that guy?

    If you bother mobilizing an expert, doesn't it seem nuts to have them just point out the obvious problems? Don't you want them to dig in and uncover the things you wouldn't learn from an amateur? To provide a critical path - a map with dangerous explosive mines clearly defined?

  7. Expert Member
    Dana Dorsett | | #7

    Just 'cuz many homes have low hanging fruit...
    ...doesn't mean that a systems approach isn't better. It's not an either/or type of thing.

    A lot of older housing stock really DOES have low hanging fruit on several fronts and fixing the lowest hanging fruit on ten of those costs less and yields a lot more than doing the full-court press on a 1982 vintage house in northern California.

    We're not talking 1980s "old"- half the housing stock in New England was built prior to 1940, and many of those have NO wall insulation, and steam heating systems using exterior stud bays as plumbing chases for the heating system, etc. Yes, you can get a lot more out of these antiques with a systems approach, but even the most basic air sealing and insulation yields a lot, at a comparatively low cost.

    The criticism of HVAC contractors' solutions is apt. I've seen HVAC contractors propose installing condensing hydronic solutions to these antiques and end up oversizing it 3x for even the air-leaky uninsulated condition of the building, let alone a post-insulated condition, yielding a modest ~30% reduction in heating costs, a reduction that could have been had at the fraction of the cost with air sealing & insulation, even keeping the 75-100 year old steam heating plant.

  8. GBA Editor
    Martin Holladay | | #8

    Response to Ted Kidd (Comment #6)
    First of all, let me say that I admire Nate Adams, and I understand his reasoning and his intent. And I am no stranger to the concept of the systems approach.

    My analysis is not really in contradiction to Nate's. Nate is arguing that an incentive program based on chasing low-hanging fruit doesn't end up with good results. Fair enough.

    My point doesn't contradict his. Here is my point: many older homes do have problems that I would describe as low-hanging fruit. Fixing these problems may not be the basis for a good incentive program, but let's not mislead homeowners: Low-hanging fruit exists, and it makes sense to fix these problems.

    So, to answer your question: My perception is not an "appeal to faith."

    Nor is it a "bandwagon fallacy" (whatever that means). I know that sealing the top of an attic chase makes sense, not because I am jumping on anyone's bandwagon, but because I have studied the issue, and I have done it.

    Is my perception an example (as you suggest) of "circular reasoning"? I don't think so. I'm not the first person to suggest that sealing cat-sized holes in basement windows or top-floor ceilings is a good idea. In what sense is my reasoning "circular"?

    Did I propose some "loaded questions," as you suggest? Re-reading my comments, I found only one question: "Not every house has low-hanging fruit. OK?"

    That question -- "OK?" -- was an attempt to establish a common understanding that many people can agree on. I don't think it was loaded.

    Did I ask (as your propose) a "meaningless question"? Perhaps. ("OK?" isn't particularly deep.)

    Did I express (as you suggest) "conventional wisdom"? Probably. Heaven knows, I'm not usually very original.

  9. Expert Member
    Dana Dorsett | | #9

    That 1982 retrofit (reponse to Ted Kidd )
    Reviewing your case example PDF it appears in the retrofit the roof deck was insulated with BIBS fiber directly against the roof deck with no roof deck ventilation, AND with foil faced polyiso on the interior side thermally breaking the rafters.

    That's a classic moisture trap, and expressly disallowed by code. The roof deck cannot dry quickly through ~0.1 perm stackup of felt + asphalt shingles, and cannnot dry at all through a 0.05 perm foil facer.

    In a super-dry climate you may be able to get away with that, but it's not exactly kosher.

    The polyiso was also was R-Max, not fire-rated Thermax, without an ignition or thermal barrier over it, which would be another violation of code.

    (Just sayin'...)

    Doing it over again you'd have at least some real drying capacity if the foam was 2" unfaced Type-II EPS instead of polyiso, with half-inch gypsum on the interior side with a coat of latex primer. At 2" the EPS would run about 1.2-1.5 perms- not exactly a class-II vapor retarder, but close enough for that cool edge of zone 4B to warm edge of zone 5B climate. It would still be a code violation since it didn't have R15-R20 of air-impermeable insulation between the fiber & roof deck, but it could still work, aided by the dryness of the climate.

    A fully cold legal build would be to put the necessary roof ventilation gap between the fiber & roof deck, in which case the foil faced iso works.

  10. Nate Adams | | #10

    Response to Martin #4 & Dana
    Martin, you are correct, there is real low hanging fruit in many homes, Cleveland is full of cool old houses with major issues. But by fixing those couple things, what have you really gained? Is the furnace going to run less now and leave the previously cold room even colder? Could it inadvertently make backdrafting worse? Will they have a noticeable effect on energy use?

    We've been trying that way for 40 years or so now. And what do we have to show for it? Obscurity. 1 HP job to every 1000 HVAC jobs. Tons of people entering the business because of the really cool applied science that is represents, but then starving to death. Chris Dorsi is a former HP contractor. So is Allison Bailes. So am I. I almost left the HP world last year and decided to give it one more real shot.

    What we're doing isn't working. Something needs to change, it's time for a conversation change.

    If homeowners were consistently told that by gaining control of heat, air, and moisture flows their home can be absolutely transformed with regards to comfort, health & safety, durability, and efficiency? (Although that's a remarkably un-sexy way to put it.) Right now big promises like that are ignored because people are cynical. There is no measurement and verification. There is no way for them to know we could deliver. We're just selling more snake oil in their eyes.

    One Knob gives homeowners something to check so they can see who they can trust. It will show who delivers real results. It is a true market mechanism to give HP the legitimacy it has never had. Until then, we will largely remain charlatans in homeowner eyes. And we should, frankly, how many HP folks have actually tracked energy results and client results? I didn't until recently...

    We have to stop telling people there is low hanging fruit. It hurts us. It hurts homeowners. It sets us back. We will remain the joke of an industry that we are, supported by government scraps. Is that what we really want?

    I think we're largely on the same page, Martin, or you wouldn't have published this, but that is more of my line of thinking underneath this post and One Knob in general.

    Dana, thanks for your defense.

  11. Nate Adams | | #11

    Reply to Brent Eubanks #3
    Brent, you have a valid point about commercial buildings. Lighting in particular is low hanging fruit and helps the bottom line. Some major HVAC misses can be there, too. Homeowners don't have those possibilities, though, precious few things in a home are cost effective, and if a client does those and considers that they have done their part, is that good? Stopping at 5-10% reductions when 30-70% reductions are possible, along with major comfort, health, and durability gains?

    Homeowners needs to be approached with a much more emotional focus, it isn't about bottom line usually. And if it is, we really can't help them except 1 out of 20 cases if they have fuel oil or propane or resistance electric and we can get them on a cheaper fuel source. And not even every time that time.

    If we can help clients to see that systems design can deliver far more than they ever expected, we have a chance to finally move forward as an industry. That's what I'm pulling for. Does that make sense? Thanks for your comment!

  12. user-1105741 | | #12

    Dana said "A lot of older housing stock really DOES have low hanging fruit on several fronts and fixing the lowest hanging fruit on ten of those costs less and yields a lot more than doing the full-court press on a 1982 vintage house in northern California."

    The bull has shat.

  13. hallie17 | | #13

    from Nate's neighborhood
    This is a good discussion to have and I definitely see both sides. I'm an architect who does a lot of addition and renovation work here in NE Ohio, and I often recommend that people get the "low hanging fruit" style audit available as part of a program by the local gas company. People have a lot of things on their minds, not every household includes someone who is comfortable with a caulk gun, and so it can be very helpful to have some professional help in identifying those cat-sized holes.

    Just getting people to think about home performance professionals is a step in the right direction. Most people I talk with don't even know what a blower door test is. That said, I can see that focusing on low hanging fruit may distract from the more significant gains to be had with a more system oriented approach.

  14. GBA Editor
    Martin Holladay | | #14

    Response to Mike MacFarland
    Barnyard humor only gets you so far. If you have a technical point to make, I'm eager to hear it.

    Although I'll let Dana speak for himself, here is my understanding of what he said: the greatest energy savings opportunities can be found at houses that waste the most energy -- in other words, older uninsulated houses in cold climates.

    There are fewer opportunities for savings in newer homes located in mild climates.

  15. user-1105741 | | #15

    Reply to Martin

    Though it seemed obvious, I'll elaborate that I'm simply calling BS to Dana's comments, as not only does he not have all of the facts necessary to make the judgements he's made (this and other comments he made), he has painted a broad brush stroke and has no data to back it up.

    If his point is as simple as you stated, then that is a ridiculous point to make. Why would we even bother saving 70% of a client's energy expense then out here in "mild" CA- when we should all move to cold climates then? Why would he even make that point- I'm giving him the benefit that his point was more intelligent than that.

    Maybe it's because the energy cost is much higher in CA, and that 70% savings represents nearly $4,000 annually? That's a good reason to fix homes, right? Maybe it's because of our hot summers and cold winters, and people like to be comfortable year round. Maybe it's because we are seeing upgraded homes sell for up to 9% more than average ones? Maybe there's value in loving your home instead of hating it? And maybe it's because of the occupant health gains from dedicated, filtered ventilation systems? Many reasons we all know.

    So I'll go up against him with the results of this one "full court press" home in our case study, and the value of all of the results obtained and the lifespan of these measures (permanent structural fixes, 50 year, 100 year structure lifespan?) versus the project cost, against Dana selecting and fixing ten old homes and and applying his "low hanging" measures, then tracking all ten over time, versus the lifespan of the measures, including equity gains and occupant comfort and health, to see who wins.

    After all, he said "...on ten of those costs less and yields a lot more" meaning obviously more yield than just energy savings.

    Never mind the irony in Dana pointing out that he thinks that our success isn't code compliant, when it was 100% code compliancy that was the miserable failure.

    Good stuff, hopefully technical enough.

  16. GBA Editor
    Martin Holladay | | #16

    Response to Mike MacFarland
    I'll let Dana speak for himself.

    In the meantime, I stand by my statement: "The greatest energy savings opportunities can be found at houses that waste the most energy -- in other words, older uninsulated houses in cold climates. There are fewer opportunities for savings in newer homes located in mild climates."

    I suspect that we are all mostly on the same page, and there is no reason to resort to talk of barnyard excrement to make any points we care to make.

    Energy retrofit work in a newer California home usually saves less energy than energy retrofit work in an older Vermont home. That's a general rule. Of course there are exceptions.

    In the case you mention, you seem to have found a California home with an annual energy bill of $5,714. Does that surprise me? No. Is that house typical? No.

  17. Tedkidd | | #17

    HOUSES SUCK!!! People want them NOT TO.
    So, is there some presumption that people with disastrous homes are calling us looking for investment advice? Because that presumption is preposterous! I meet very few people who want me to help them turn their homes into retirement plans.

    People are not calling because they are anxious to save $400 a year on their energy bill. That is simply NOT the market!!

    The reason we are called is peoples houses SUCK - and homeowners want them to NOT SUCK! When you introduce "cost effectiveness" into the Home Performance discussion, you shift from fixing PROBLEMS to doing things that will be "free". You've shifted focus to a fluctuating irrelevancy that now has high likelihood of TAKING OVER the design/decision making process.

    REALITY CHECK - In an environment of very cheap energy the idea that making a crappy house NOT SUCK essentially for free is absurd! It has been my experience that contractors who "grab low hanging fruit for their clients" are actually grabbing the stuff that is most profitable for THEM, and leaving without solving the SUCK issue.

    I wish I could come up with a poignant analogy. It's like deciding you can't justify expensive tires and wheels for your Ferrari, so instead you go with bicycle wheels. That's a lot of trouble to go nowhere fast.

    "Low Hanging Fruit" is usually a small part of the system of interconnecting systems that must function together in balance. You need to make improvement decisions based upon how all these systems work together, and the climate/environment where the house exists, the homeowners budget, energy savings opportunity, and incentive availability. If you make it based upon some arbitrary "cost effectiveness" which, by the way, will shift every time fuel costs shift you are not likely to significantly impact SUCK.

    When you introduce "cost effective" to the discussion it puts tremendous downward pressure on quality. It also implies design for fixing a house correctly will and should change on a daily basis with fuel rates.

  18. GBA Editor
    Martin Holladay | | #18

    Response to Ted Kidd
    Some people -- especially those with a budget that can afford $20,000 to $30,000 energy retrofit jobs -- are delighted to have a home performance contractor fix their house and make it more comfortable. Nate Adams is evidently now successfully finding those clients and satisfying them. That's good.

    Other homeowners can't afford this type of work, and are more interested in cost-effectiveness. That's totally understandable.

    I'm confused by your statement: "It has been my experience that contractors who grab low hanging fruit for their clients are actually grabbing the stuff that is most profitable for THEM, and leaving without solving the SUCK issue." The reason I'm confused is that Nate was making the opposite argument: that his business was going broke when he tried to grab the low-hanging fruit, but his business is profitable now that he has found clients willing to pay him $20,000 to $30,000 for energy retrofit work.

  19. Tedkidd | | #19

    Martin, that's really weak argument and you know it.
    So you presume to know what people can afford? Ok, what can they afford then?
    Come on, you know that's an all encompassing and completely idiotic position.

    And it's completely false.

    Possibly this poor critical thinking is why what seems so simple to me and Nate is so confounding to (some) folks. That and intellectual capacity, openness, or most likely an unwillingness to really put think time to understanding it.

    Really, you don't have to be that smart, but you can't be lazy.

    Look, $20,000 over 15 year is what, $147 a month? And if that saves $70, the net monthly cost is $77. If you have $20,000 worth of SUCK in your house, typically you are THRILLED to only pay $77 to make it go away. They're THRILLED to leverage energy savings into greater SUCK removal. You don't have to be rich.

    And in NY, you can put 1/2 of that 20 "On Bill" - which means that portion of the debt stays with the electric meter if you move.

    Can't afford $77 a month? What can you afford? I don't want to take food off your childrens plates, what can you afford? Martin, tell me what people can afford? How badly do you want to solve this SUCK list?

    Seriously, you have no clue what people can afford until you ask. If you don't ASK you are an ass, and if you design solutions around a presumption of affordability, you are NOT designing to solve problems you are designing for what you hope to sell. Proposing solutions people can't afford is asinine, just as proposing less than they can afford and leaving without solving the SUCK list is.

    Look, I do this in NY, and now I've taught Nate to do it. Saying it can't be done is BS.

    And with no accountability for results, this is the low integrity environment that we currently live in. Accountability for results fixes it. But it needs to be on a scale larger than 4-5 contractors in the whole country.

    MacFarland isn't even changing the market in Redmond. We start keeping score and this starts fixing itself. We need JD Powers for Home Performance.

  20. GBA Editor
    Martin Holladay | | #20

    Response to Ted Kidd
    Really, I'm glad you have happy clients. But calling me an ass isn't helping.

    You're right that some customers are able to pay for $20,000 or $30,000 energy retrofit jobs, especially those with full-time jobs and access to bank credit. If you look around, however, you'll realize that a lot of people don't fit that category.

    And if a potential customer happens to ask about cost-effectiveness, I advise you to resist the temptation to call them an ass.

  21. user-1105741 | | #21

    I'm on the same page


    I'm on the same page with you that older homes in Vermont offer more opportunity for energy savings than newer homes in CA.

    What I have issues with is the contradiction of statements that Dana can address.

    Dana said "I plugged a heluva lot of holes in my house without seeming to make a difference, before I found the 4" x 12 foot hole in the framing in a tight spot behind an attic kneewall where the roof transitioned over a ventilated porch roof."

    What we can conclude by this statement is that time was spent between phases of air sealing (evidenced by the "without seeming to make a difference" meaning there were bills or seasons between efforts) and finally an elusive, final hole made most/all of the difference.

    Next, on a subsequent post, Dana states "We're not talking 1980s "old"- half the housing stock in New England was built prior to 1940....Yes, you can get a lot more out of these antiques with a systems approach, but even the most basic air sealing and insulation yields a lot, at a comparatively low cost." on these ten homes that you're going to be LESS familiar with than your own home....the ones you're going to beat our "full court press" with......somehow you are going to arrive knowing exactly where the one magical FOUR SQUARE FOOT hole is to seal on each one, the black hole that makes all of the difference (the same one you couldn't find within your own?)

    You sold us all on the difficultly and importance of meticulously locating and sealing all of the holes, which is something I firmly believe in, because we only get one chance to do that, and doing a poor job of it has little to no real lasting effects (as you mentioned). Then you seemed to contradict yourself by saying essentially the opposite, which is not based on best practices, good science, or sound logic.

    So the bull did his thing, funny or not.

  22. Tedkidd | | #22

    "People can't afford $77 a month." (?)

    I'm sorry if I hurt your feelings. I'll be gentler now I know your skin thickness. =) (Feel free to bust my chops any time.)

    Back to the issue of affordability. You claim people can't afford to fix their houses. I guess you think they can't afford $77 a month (as I actually do this work, I beg to differ). If you have serious performance, health, or safety problems and can't afford to invest $77 a month, a home is probably not an appropriate thing for you to own.

    But I'd like to hear from you what people can afford to fix their homes. What is an affordable number, $50? If they have high energy bills, I'll help them optimally leverage the opportunity to get as much fixed as they can afford now, and a plan for later.

    Energy Efficiency will be an outcome, not a goal. Well designed solutions to problems, bringing the house into balance, will harvest energy savings as part of solving problems. This is all BPI stuff.

    What I won't do? I won't sell them a "low hanging fruit solution" that will "save" them lots of energy in theory but not in practice, and also not address the problems that brought me to the house in the first place.

    This is no "holier than thou" thing. Eventually technology will make tracking results simple. Once that happens, it's a small step to comparing to promised savings - kinda like JD Powers for Home Performance:

    Or this:

    Or this:

    Once that happens, there will be a lot of people with their shorts around their ankles. I don't want to be one of them, I want to be with the guys at the top.

  23. GBA Editor
    Martin Holladay | | #23

    Response to Ted Kidd
    I notice that you have been posting similar comments on this topic on two different pages. Rather than answer twice -- and post identical answers on two different pages -- I have chosen to post my answer on the other thread. Here is a link to my response.

  24. Expert Member
    Dana Dorsett | | #24

    The more detailed story (response to Mike MacFarland )
    A responsible air-sealing contractor with a blower door would have found that out-of-the way large air leak on the first pass (along with the other air leaks in more obvious places that had been dealt with.)

    Fixing the big air leak had a barely perceptible effect on the heating bill (in the statistical noise, low single digits percentage at most) , but the difference in wintertime indoor air humidity was telling- it now NEVER drops below ~30% RH even during cold snaps, whereas prior to fixing the leak 25% wasn't rare.

    The blower door test on THIS place is still pending- there was (and is) plenty of obvious remediation to be done, and the heating energy use had been cut by more than 30% prior to fixing that air leak. There was quite a bit of other work done prior to fixing that leak, work that had easily measurable effects on energy use:

    The house as-built in 1923 had a funky half-inch thick kraft/horse hair/kraft laminate woven between the studs (cutting the stud bays on the diagonal) for insulation. Dense packing the stud bays with cellulose resulted in a ~15% cut in fuel use per degree-day, and a noticeable improvement in comfort, clearly a low-hanging plumb to be plucked, but clearly not the whole shebang. The dense packing likely made a real difference on infiltration rates, but that was never tested with a blower door.

    Insulating the poured concrete foundation with 3" of interior polyiso (also low hanging fruit) cut it ~15% from that lower fuel use point, and the basement now never drops below 65F (ostensibly due to distribution losses from the heating system), even when we're heating primarily with the wood stove on the first floor.

    Insulating the roof deck behind the kneewalls with spray foam (but somehow missing that air leak) yielded another high single-digits drop in the heating energy use.

    It's still a work in progress- the size of the lowest-hanging fruits are now going to be smaller, but there is still some dead-obvious stuff to fix.

    And yes, an insulation contractor with a blower door could have walked into this place and figured out where most of that low hanging fruit lived without any trouble at all (even the more hidden stuff that it took a part-time idiot like me months to figure out.)

  25. Tedkidd | | #25

    Dana, I don't think you are
    Dana, I don't think you are going to get this not because you aren't smart - it seems you don't want to.

    First, low hanging fruit is easy and obvious. If you missed it, then it wasn't low hanging.

    Second, low hanging fruit supposedly has great financial return. You are claiming things to be "low hanging" without addressing cost or benefit. If they are so great, what do they save?

    Third, the presumption a "professional" is coming with an eye to saving energy rather than selling their preferred product is incredibly naive.

    Forth, and most important, it's about finding deficiencies, it's about design. It's understanding how things interconnect. It's understanding how to bring the house into balance rather than making it more OUT of balance.

    You might want to reread Mike's story about the energy pro selling $15k worth of equipment would supposedly pay for itself:

    What was the outcome - 1/5 of the savings projected? This is 95% of the work I see. Grab the big sale, to hell with the consequences. And it will stay this way until there is transparency, accountability and INCENTIVE for good outcomes:

  26. GBA Editor
    Martin Holladay | | #26

    Response to Ted Kidd
    I really hope you aren't trying to argue that air sealing work on an attic floor plus installation of cellulose insulation on the attic floor in an old, poorly insulated cold-climate home isn't:

    (a) an example of low-hanging fruit, and
    (b) cost-effective.

    Because if that's what you're arguing, I'll have to send Michael Blasnik an e-mail so that he can provide you data that shows otherwise.

  27. Nate Adams | | #27

    Response to Martin #26
    Martin, yes, attic air sealing and insulation IS an example of low hanging fruit. And also one that I have found causes issues.

    Example 1: Just yesterday at a client home he wanted to insulate his attic and a few select walls of a cold room. I told him that would likely drop his heating load by 30-40%, and now his furnace would be substantially oversized. At 71K btus delivered (88 nominal) the furnace is not too far off currently, probably still 20K oversized, but not hideous. If his load fell to under 40K, though, other rooms would likely get cold. I heard this exact result from a number of my former clients.

    What happens when people get uncomfortable? They turn up the thermostat, or open windows, or turn on the AC (!)

    Example 2: My mom just told me that to keep the apartment over their garage warm while my grandma was there in hospice care, she had to open the windows in her bedroom, which is on the same furnace. She even turned on the AC on the first floor (the house has 2 furnaces and ACs) to keep the house comfortable in shoulder seasons.

    Yes, one furnace and one AC were running simultaneously.

    That home is 5300 sf, was built in 1991, and has a 7200 blower door. My dad told me the energy bill was the same as their old 1903 1300 sf farmhouse, exactly 1/4 the size. The 'new' house was well insulated, but the knee walls over the garage made things weird. It also has WAY too big of heating equipment, an 80K and a 100K furnace, up and down, which also contributes to the garage apartment being uncomfortable.

    If we don't design comprehensively for comfort, crazy crap like this happens. What happens to energy bills when an attic is well insulated but clients still aren't comfortable and they pull stuff like this? I cringe to think about my mom's energy bills...

    Anything short of comprehensive retrofits is likely to fail to deliver good results either for comfort or energy bills. How low is that fruit, really?

  28. Tedkidd | | #28

    Martin, Mike and Nate are wrong - this is beyond your capacity

    Because Michael Blasnik says so, it must be true? Next you'll be suggesting everyone should just buy thermostats, that's where all the REALLY big savings opportunity lies.

    The difference between what you propose and what I propose is you ASSUME cost effectiveness and jump right to doing work. You seem very comfortable giving prescriptive advice without any diagnoses or due diligence. (BTW, most work done this way is low bid, and terribly implemented with shortcuts taken in all the wrong places)

    Even if cost effectiveness of a measure were relevant, insulating an attic floor is not "always" a cost effective recommendation. This doesn't matter when you do 1000 free projects, across the data-set the winners outweigh the losers - and the losers aren't out of pocket so they can't cry foul. I had weatherization do some really crappy and ineffective work to a rental. No result. Fortunately no cost either. But hey, blow enough insulation and some will save energy.

    THIS IS NOT FREE WEATHERIZATION - you are asking homeowners to spend serious money!! You need to have a result for EVERY CLIENT! Jumping to conclusions does not bring those results - and it's malpractice.

    I get it, I use to think "just do the work" too. Now I find it distasteful and self serving for an "expert" to recommend "solutions" and shortcutting the design process. It's even worse than the HVAC guy who doesn't do a blower door or load calc because "he knows what the house needs". How is that anything but self-serving?

    EVERY HOUSE IS DIFFERENT! Add variation in occupant needs and budget and the answer isn't simply "let's blow some insulation in the attic". A journalist who understands integrity should be able to see this.

    Martin - it seems easy for you to make claims you have no accountability for. When your suggestions hurt someone - "Oh well, I'll figure out a way to blame it on something they did" - right? Jump right to the old "Occupant Behavior" cop out.

    Why are you in such a big hurry? When one of the largest costs is client acquisition, why are you in such a rush to get their money and get out of the house? You've gone to all the trouble of getting there, why not slow down and do the home and homeowner justice? Why not be thorough?

    I keep looking and hoping for integrity from your words, all I'm finding is equivocation and disappointment.

  29. GBA Editor
    Martin Holladay | | #29

    Response to Ted Kidd
    Anyone who chooses to insult the abilities of the person he is debating (that is, to make an ad hominem attack) instead of grappling with the technical issues is usually defending a weakly supported position.

    If it comforts you to think that I am unable to understand the issues arising from oversized furnaces ("this is beyond your capacity"), I will not try to disabuse you of a belief that provides you comfort.

    Your point -- that "insulating an attic floor is not always a cost-effective recommendation" -- is an obvious one. That's why I wrote (way back in Comment #4) that "Not every house has low-hanging fruit. But a lot of them do, especially in neighborhoods with old houses."

  30. Tedkidd | | #30

    Martin, I may have devolved into fallacy, but I followed you there.

    "People can't afford it"

    - - - Prove it. Tell us what they can afford. Nope, you won't support your contention nor give a number they CAN afford.

    "Low hanging fruit works"

    - - - Again, show us numbers. Let's see the savings of a couple of your mythical "low hanging" projects? You already admitted these retrofits are NOT living up to their savings projections which is supported by realization data from all the states I've seen. But then you turn around and claim these same efforts are big energy savings opportunities? Which is it Martin? Be nice if you would pick one position and stick to it.


    You seem unable to make the connection from poor realization rate to the concept that the low hanging fruit these programs chase works in theory but not in practice. When you track actual results it simply does not work as an investment unless you think getting 1/2 of what you were expecting is "good".

    As NATE ADAMS writes in his recently published article in Journal of Light Construction:

    "Comfort issues are my immediate concern, partly because they can be so difficult to solve. But solv-
    ing for comfort usually fixes root problems, and energy efficiency tags along like a loyal puppy. "

    Home Performance is not a financial investment justified solely by energy savings. Once you see and accept this, if you have integrity you can no longer suggest decisions be made based upon "best saving opportunity". It is an absurd approach to decision making. You are setting expectations that are unreasonably high and promoting a dishonest conversation, and encouraging homeowners to not go deep enough to either solve problems or optimize savings. People live in homes that perform crappy and they are tired of it. They invite us in because they want their home to no longer be crappy, not because they think we can help them save for retirement. Energy savings is the icing, not the cake.

    Home Performance is fixing problems with good design instead of bad design. Good design brings a home's performance into balance in a way that also saves significant amounts of energy. Home Performance is about leveraging energy savings into making more comprehensive fixes affordable. We do this by leveraging savings opportunity into improvement budget. It's not about getting homes fixed for free. At current energy prices you simply can't squeeze two gallons of milk from a one gallon jug. This presumption they will be"free" is a big reason savings are so exaggerated (along with no accountability for or transparency of results).

    I agreed with you that people with no house issues looking for pure return on investment energy play should go with solar. At these energy prices it is a rare and exceedingly crappy home that has high "payback" opportunity purely on energy savings.

    But you then circle back to the idea of cost effectiveness in home "improvements". You simply can not seem to see how the numbers don't work even after stating they don't work. You don't see the contradictions in your statements, and seem unwilling to follow a line of logical debate to it's conclusion once you feel it might be heading in a direction that contradicts your preconceived beliefs.

    Step back. Look at all the evidence. Look at the math. The numbers don't connect for a reason.

  31. wjrobinson | | #31

    Room for more than one
    Tedd, most of us by now get your message. And we get Martin's.

    As to posts... I love Nate's posts... sounds like someone I wish lived nearby to chat with in person.

    Tedd, I hope you appreciate Martin as most of us do. This site is a great huge site of info that many of us have easy access to verses prior to this site... fo get bout it.

    Oh and there are some other must read posters here... Dana being another among many.

    I appreciate Nate's positive inciteful posts. Tedd... add some new points... beside fruit and where it is hung or not. I bet you have lots more to offer.

  32. Expert Member
    Dana Dorsett | | #32

    Response to Ted Kid (#25)
    "First, low hanging fruit is easy and obvious. If you missed it, then it wasn't low hanging."

    Indeed, it is/was, in my house. The somewhat hidden air-leak that made the difference on humidity levels was a tiny fraction of the energy reductions that were already achieved going after the low hanging fruit:

    "Second, low hanging fruit supposedly has great financial return. You are claiming things to be "low hanging" without addressing cost or benefit. If they are so great, what do they save?"

    In my case I've been approaching the low hanging fruit on a best bang/buck basis first (and yes, the subsidies skew the order in which things actually get done.)

    "Third, the presumption a "professional" is coming with an eye to saving energy rather than selling their preferred product is incredibly naive."

    A presumption that I never make.

    "Forth, and most important, it's about finding deficiencies, it's about design. It's understanding how things interconnect. It's understanding how to bring the house into balance rather than making it more OUT of balance. "

    No kidding? Didn't see that one coming! :-) (BTW: Presume that was meant to be "Fourth...", and not "Forth..." thus... )

    " You might want to reread Mike's story about the energy pro selling $15k worth of equipment would supposedly pay for itself:"

    I probably read it in much greater detail than most of the people posting here (maybe even more detail than you?), picking up on some blatant code violations that were executed during the thermal retrofits by the folks who perhaps better-understood the energy issues with the house, but apparently not very much about the moisture management issues, as I pointed out in response #9.

    There are no rocket scientists wasting their careers pointing out that ducted HVAC systems that penetrate both the pressure & thermal boundaries of the structure are prone to severe efficiency & comfort issues. I'd call that low hanging fruit from an analysis point of view, but the net present value may not always be there for doing the extensive retrofit that was eventually done to bring it all inside. Hopefully they won't have to replace the roof deck due to the (code violation) moisture trap they installed, or have to replace the house after what might have been a minor-fire (had it been done to code) to the absence of a thermal barrier on non-fire-rated foam in the min-attic that still had mechanical equipment and active ductwork in it.

  33. GBA Editor
    Martin Holladay | | #33

    Response to Ted Kidd
    You wrote, "It's pretty simple math." So is the relation between heat flow and insulation R-value. But any of us can stumble -- as you did when you challenged my math in a comment on another blog.

    In your comment, you started by quoting my previous comment: " 'If you double the R-value of your insulation, the rate of heat loss is cut in half.' "

    You then responded: "Wrong. That's not the case."

    Well, actually it is. But math can be tricky, can't it?

  34. user-1105741 | | #34

    Dana said " I probably read
    Dana said " I probably read it in much greater detail than most of the people posting here (maybe even more detail than you?), picking up on some blatant code violations that were executed during the thermal retrofits by the folks who perhaps better-understood the energy issues with the house, but apparently not very much about the moisture management issues, as I pointed out..."

    And the ignorant rant from the code expert DIY'er continues. Maybe you should go back and re-read my previous comments about your BS, before continuing to claim your superior knowledge of my climate and jumping to ridiculous conclusions.

  35. GBA Editor
    Martin Holladay | | #35

    Response to Mike MacFarland (Comment #34)
    There is a good chance that you are correct about the code issues raised by Dana, but readers of GBA have no way of knowing whether you are technically correct or not. Instead of discussing the code issues (perhaps by citing a section of the code in your own defense), you chose to label Dana's comments as "ignorant" and disparage him as a "DIY'er."

    A technical discussion is always more enlightening than name-calling.

  36. Expert Member
    Dana Dorsett | | #36

    Hey Mike-
    A moisture trap is a moisture trap- in any climate.

    A roof deck sandwiched between foil facers and a composite shingle layup without benefit of ventilation is susceptible.

    I was speculating that you MIGHT be able to get away with it in that climate (trying be generous) if it was dry enough that the roof deck could dry toward the exterior through the ~0.1perm roofing stackup, but certainly not concluding that it was a given.

    Being less generous I might have simply stated that while many aspects were done well, the code violations, and particularly the moisture trap, are an embarrassment to the industry.

  37. Expert Member
    Dana Dorsett | | #37

    But Martin...
    No really - the bull really HAS shat!

    Said bovine in his linked-to document describing his project he concludes with:


    "HP Process:

    1. Building performance test equipment used by skilled technicians
    to identify and quantify the problem areas

    2. Application of modern building science to provide solutions

    3. Meticulous attention to installation details and uncompromising
    quality of installation and installer verification during process

    4. Data collection and results tracking as feedback to further improve"


    I'll grant him 1& 4, but 2 & 3 are at best dubious or need footnotes, given the gross violation of some very basic building-science on how to deal with non-vented insulated roof assemblies.

    Being able to dis-aggregate the power use, run blower doors & use IR imaging is all useful stuff, but it's not building science, it's not even engineering.

    The value of those diagnostic methods are more useful in some projects than others. It's not clear how much of that was truly necessary in this project. It surely didn't hurt, but given where the original ducts were routed, it doesn't take insight gleaned from those tools to know where the major problems lie.

    While the diagnosis was correct, the design & execution of the "cure" was severely flawed on a building-science basis. It meets the energy use goals, but it was done in such a way that it' s a set-up for future problems. Maybe they'll get away with the moisture trap for a several years- maybe even more than a decade, sell the house an move on. But the history on moisture-trap stackups isn't very good.

    With unfaced EPS as the interior side vapor retarder instead of foil faced foam it might have a long-term chance. I'm giving this one until the first minor roof leak has a year or three to work it's magic.

    But of course, how could I (a mere DIY-er !) be expected to know anything about how systems & buildings work in the REAL world, eh? ;-)

    I'm, not sufficiently impressed with Mike's awesomeness despite his nice collection of measurement tools, given how easily he either misses, overlooks, &/or dismisses basic moisture management problems with the roof insulation stackup implemented in his example project. ( But at least he takes constructive criticism well. :-) )

  38. Nate Adams | | #38

    Reply to Dana #37
    Knowing Mike, he thought long and hard through that assembly. If there is a ridge vent on the top, it's likely to work according to what Joe Lstiburek has found recently. Joe is trying to get dense packing cathedral ceilings into code now. I'm not sure exactly how it applies to this assembly, but Joe says as long as the moisture can get out by going up, you're good.

    The key to good install is using the blower door to check details, which almost no one does. I find at least a couple hundred points on my projects doing this, sometimes you might catch a big hole. Maybe one contractor out of 50 does this during the job. Before and after isn't good enough. So it's a big point.

    A key thing to keep in mind is that he actually sold and performed a project like that. Only a handful of people in the country can do that. He does have a program that supports him well, but it's not something many can do regardless. He's on the bleeding edge of HP.

    It's far easier to criticize than to build up, I always cringe when I post job details because someone will always tear them down...

  39. Expert Member
    Dana Dorsett | | #39

    That's good feedback
    Can you show me how installing a ridge vent on a dense-packed unvented roof is supposed to work? What are the details of Dr. Joe's "likely to work" assembly?

    Dense-packed cellulose is going to be more forgiving than dense-packed fiberglass, but it will still flunk the resilience test with Class-I vapor tightness toward the interior.

    Even if on some theory Mike's stack up can work with a ridge vent (and I'm a strong skeptic on that), in the writeup there is no verbal or visual evidence of a ridge vents, on what was originally a gable-vented attic space, as seen in the photographs on pages 15 & 19.

    Dense packing fiberglass into cathedral ceilings isn't going to work with a 0.05 perm interior and no venting. If instead of R10 polyiso he had use R10-R12 Type-II EPS the vapor permeance to the interior would have been about 1 perm, which is pretty vapor tight, but open enough to have some drying capacity. While not perfectly compliant with the letter of code, at R10-R12 Type-II EPS damned close to Class-II vapor retardency, and should work pretty well in a N.CA climate.

    Alternatively, using closed cell spray polyurethane foam against the roof deck to the appropriate R-ratio to comply with IRC Chapter 8, the stud edges can be thermally broken with ~2" wide strips of 1.5" /R10 polyiso, with the BIBS fiberglass coming out flush to the interior facer of the polyiso, with half-inch gypsum as the interior air barrier. That would have nearly identical or slightly higher whole-assembly thermal performance,and it would be WAY ahead on moisture resilience. But that is more construction steps, and another subcontractor to apply the ccSPF.

    I actively like Mike's use of duct mastic over the FSK tape on the polyiso as long term seam-tightness insurance. I'm still a long term tape-adhesive skeptic (though I'm coming around on that a bit.) The problem I have is that while some adhesives may work, but many clearly don't, and it's hard to know in 2014 which ones will still be working in 2054 & beyond. Duct mastic has a long and mostly successful history.

    I understand the cringe factor when publishing project write-ups, but avoiding moisture traps in the stackup is building-science 101. Mike's writeup is advertising "Application of modern building science to provide solutions". This one doesn't take a WUFI simulation to analyze, and there is even guidance on that in the IRC which was apparently ignored.

    Hopefully this project won't become one of those worst-case scenarios- I've seen moisture trap assemblies go 20 years without problem, but I've also seen them go completely off the rails. The fact that the roof deck is milled plank sheathing rather than OSB or plywood may give it a bit more time before it's too punky to work with. On a re-roofing (not that Mike would be around for that) stripping it down to the bare planking and re-applying #15 felt over the structure roof deck, then using 2x furring to support a vented OSB or plywood nailer deck for new shingle & felt stackup would give it substantial drying capacity toward the exterior, mitigating further structural compromise to the roof deck and rafters.

    Mike gets an A+ on measurement & diagnostics, an A+ on air sealing, a B+ on the thermal envelope performance, but a D- on the moisture management on roof assembly,, and an F on building code compliance. This type of retrofit CAN be done in a moisture resilient & code compliant manner, and my reason for spelling it out is the hope that anyone executing similar retrofits would pay some attention to those issues.

    But I'm just a willfully ignorant idiot who doesn't even own a blower door- why would anybody listen to me? ;-)

  40. user-1105741 | | #40

    Big hat, no cattle
    There's a phrase we use in Northern CA for those that lack practical experience. We call it "Big hat, No cattle."

    Dana, if you were knowledgeable about my climate, as well as best available building science from companies like Building Science Corp, you would know that what has been built is not a classic moisture trap, as you would have us believe. Your ignorance is in assuming what is above the area you saw, which in reality is not a solid roof substrate, nor is it a foil sandwich. The roof deck is comprised of spaced wood boards about 1 inch apart, with lapped tar paper and asphalt shingles directly attached. In essence the entire roof is continuously vented, and there is't any way moisture can become trapped by it since we are always drying to the outside. The only moisture that can enter is either from bulk water leakage (a problem for any home), or solar vapor drive. And because our average monthly outdoor temperatures remain at or above the 45°DB average decision-making threshold (see BSC's Hot dry/mixed dry climate handbook) , we maintain plentiful drying potential year-round, keeping the dewpoint of the substrate out of any danger zone.

    Additionally as spelled out in the presentation, we installed a continuously operating and balanced ducted HRV ventilation system to control interior relative humidity to maintain it below 45% in the heating season. We also went through extensive and meticulous attention to air sealing details to ensure that air from below cannot enter the enclosed rafter areas. So not only are we vapor open on top and drying to the exterior, but we chose an air permeable insulation to permit better ventilation, all the while carefully maintaining relative humidity in the home below to control the dewpoint of any air that could possibly leak into this assembly.

    And then there's the assumption that we are 100% done with this home. Just because we were not able to install additional insulation on the roof deck at this time, doesn't mean it's not planned for the future when the roofing shingles have reached the end of their lifespan. At that point, we will be installing foam insulation, and ensuring that the pressure boundary is connected in continuous at this location. This was a project on a fixed budget that needed to produce incredible results in order to turn a family's financial state around.

    Now regarding the covering of the R-Max insulation, the majority of the material was directly covered by half inch gypsum board, with upper triangular portion above the ceiling left exposed. We have no source of combustion in this space, with only a small fan and refrigerant coil within a sealed air handler cabinet. Our building inspector approved the installation. I'm not saying that it couldn't or shouldn't have been covered with something, but any covering cost and not contribute to the performance goals for this project. And I also never proposed this as the best solution for anyone, but rather a solution for this particular home with their particular budget. A young family living downstairs during this reconstruction could not be subjected to spray foam, which would have been the popular internet choice. But when you leave the perfect world of the Internet and do real world projects, there are often decisions and choices that are made that accomplish goals but still have drawbacks. The presentation demonstrates everything exactly as we said.

    This young family went from being right on the edge of losing their home and by taking a step of faith to fix it, and they are extremely comfortable and able to provide a much higher standard of living for themselves afterwards. The whole reason why I shared this presentation was to help others learn they too can be free from financial oppression despite currently living in fully code compliant, poorly performing housing stock.

    So rather than critique the success stories and point out silly issues without of all of the pertinent facts, it would be better for you to spend more time fixing homes and learning from your own efforts to better humanity. In the process you may come down from your elevated perch, finding less enjoyment of mocking newbies who post terms like "watts/hr" which you were quick to point out is inaccurate. That's classic big hat, no cattle, serving no useful purpose whatsoever.

  41. Expert Member
    Dana Dorsett | | #41

    Using 1x planking with
    Using 1x planking with spacing under a 0.1 perm roofing stackup is a dubious ventilation scheme at best, but it's better than ship-lap I suppose. (Dare I mention that it doesn't meet code for a ventilated roof?)

    It doesn't matter that you have an HRV controlling wintertime humidity, as long as it's air tight and not SUPER vapor open on the interior. There's no need for foil facers, it only reduces resilience. The facers make it easier to air seal though.

    I'm glad to hear that you intend to deal with the shortcomings at the point of re-roofing. Without any mention of that in the write-up was no reason to presume that there would be any followup there. Why WOULD anyone presume you were going to be there? "Maybe yes, probably not" was my take, in the absence of any hint that it was still a work in progress. To assume that there would be followup would have to rely on facts not in evidence.

    I've seen inspectors give a pass on exposed polyiso too, even when there was mechanical equipment in the space. That doesn't mean it actually met code, only that the inspector is also now on the hook for it in a worst-case scenario, not just you.

    It's not clear to me why you presume to prescribe that " would be better for you to spend more time fixing homes and learning from your own efforts to better humanity." I've been involved at the both planning & execution stages of multiple deep deep energy retrofits (at several different budget levels) as well as new home designs, and will continue to point out potential problems on presented projects when I see them. When you don't actually include the "pertinent facts" in the write up that may mitigate the "silly issues", those issue really aren't silly at all- they need to be explained.

    If there is anybody is sitting on an "elevated perch" here is it's the cowboy on the high horse slinging petty "ignorant", "silly " or "big hat, no cattle" ad hominem barbs for not licking the shit off his boots & worshiping the successful energy reduction of his project. Simply sticking to the topic, explaining any mitigating factors surrounding the issues raised on the first go-around would have been more of an eye-to-eye level conversation.

    This was your first response to the issues I raised back in post #9 that had any substance to it, yet even THIS came sprinkled with more inane attempts at insult. I'm glad you finally got around to the substance of it but it didn't really need to take the path YOU steered it onto. Simply slinging invective doesn't show that you have any insight into the topics raised.

    Your chosen reactions make you appear to be insecure, petty, and vindictive- characteristics I would not want in a professional that would consider hiring. Maybe those characteristics don't really apply to you, but here again, I'd have to rely on facts not in evidence to presume that.

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