A Twitter Conversation – Moving Along, Part 2

Previous Info on the Conversation

OK!  Since I posted Thursday night, things are moving.  People are talking to each other and it is becoming evident that a few more are involved that were not listed originally.  Also, not being from Derby, CT – where they have 200 – 300 year old houses, with much historical value to preserve – I am finding that I don’t know as much as I thought – or that I don’t know how to apply what I do know.

Additional Players that have been brought forth are:

  • Martin Holladay:  In the Twitterverse he is known as the Energy Nerd.  His blog is full of interesting stories and tidbits of knowledge.
  • Carl Seville:  His blog and in Twitterverse he is the Green Curmudgeon. He has his own outlook on all things Green and brings a wealth of info to the table from his experience as a builder.
  • Then there is JB.  Hailing all of us from Baltimore, JB is in construction and remodeling.  Since Baltimore has been around since before the night when ‘Whose broad stripes and bright stars thru the perilous fight,’ was observed and recorded; they, like Derby, CT have some of those 200 – 300 year old homes to work with!  JB has a blog,  Building Moxie.

Welcome to the > 140 Convo.

Since Thursday

John P.  left a comment on Sean’s Blog Post regarding some of his concerns.

  • The stereotype carried by some that DER requires extreme measures.
  • Not destroying historic fabric
  • Reversible
  • The concept of ‘the house is a system’ means that houses built 300 years ago, may work well as their own system, but when a new construction method for current housing is introduced, then the law of unintended consequences intervenes.
  • Work on Energy Efficiency should be staged and completed over a number of phases and years.

He also discussed the definition of ‘Deep’, countering my proposed use of the Wiki definition at 30% reduction. John offered some additional criteria. Primarily he is proposing to include climate in the definition of Deep.

Updating the Conversation

I want to pose some questions and try to clarify where we are going and where we need to go. I also want to respond to John’s ideas on refining the definition of Deep.

John’s first point was stereotypes.  That is my word, and I chose it specifically because when people deal with what they assume about another they are creating a stereotype. I believe the best way to deal with those is to get to know the other person or position and thus my participation in this conversation.

The second point he makes is not destroying the Historic Fabric of the home.   I can agree to this one.  I don’t like changing the looks of a home, just to improve energy efficiency.

  1. It is usually not cost effective.
  2. It can become a distraction from the original intent.
  3. If you don’t like the looks of an old historic property, what are you doing working on one?

I believe his third and fourth points are inter-related.  If you cause a problem with a change in how the home works, you need to be able to undo the change.  Therefore, changing the exterior, by removing siding to install rigid foam insulation and then re-installing the original siding might be reversible. That would depend on how you treated the windows and doors due to the increased thickness of the walls.  In the end, I think most of these types of improvements will not be cost effective in energy savings.

In my first post is had a couple of points that I believe must be kept in mind.

Significant Savings from the improvements

  • Savings from improvements are probably best considered significant over a 15 – 25 year period. At the end of that time, a different property owner may be present, new methods of improvements may be available, increased prices of energy make a revision of the cost effectiveness calculations essential.

Work that is Safety Related may not have a dollar savings.

  • How do you calculate the savings in replacing Knob and tube wiring with modern wiring?
  • What about reductions in water presence anywhere in the building that it is not designed to be? What about comfort of the building occupants? When people are uncomfortable, they do many things. Electric resistance space heaters are expensive to operate and are unsafe.
  • Other items related to Building Code issues.

Defining a Deep Energy Retrofit. #DER

The closest I have worked to one of Derby, CT’s older houses is a 92 year old home in Wichita.  I wrote about that audit and the following upgrades in ‘What Good is an Energy Audit?’  The cost effectiveness I think should considered is illustrated here by the proposed improvement to the uninsulated walls. It took 99 years. Doing it for less would have involved drilling the brick exterior and leaving an obvious patch.

With the exception of the exposed insulation on the basement walls and weatherstripping on one door, none of the energy efficient improvements were visible. The total cost of  improvements will be returned to the homeowner in 14 years, assuming no increase in electric or natural gas rates.

In percentage terms, this plan mets the definition of 30% or more. If you look at energy cost reduction, it figures at 36%; if you look at peak power reduction (summer) it is 41%; if you look at CarbonDioxide reduction it is 34%.

The insulation contractor on this project was Northstar Comfort Systems. @Nstarcomfort They did a good job, the home owner is very pleased and the project verification was achieved on the first visit.

John has suggested adding climate into the definition of deep. I think it is already there.  If you moved this house from Wichita to Maine, the pre-improvment costs would be higher, due to weather and cost of energy. Weather is obvious, cost of electricity in KS is about 10 cents per KWH and in Maine about 17 cents.  The reduction in use of BTU would be at least what it was here in Wichita.

I don’t think climate needs to be added because it is already there. The idea of savings has to be based on what the house is already spending.  Weather is part of that calculation.

I think a simple percentage is adequate to define Deep. It works, it accounts for all variables and it follows the KISS principle. It works for several different metrics, dollars, BTU or your favorite energy measure, or environmental like carbon.

Comfort and Safety

I think the ideas of safety should be self evident and I would also include durability in them.  If a home is aged in centuries, it must have been durable.  If a home is aged in decades, it must have been durable. It is up to every homeowner to continue to maintain and improve on durability.  That is why we look at a new roof or repainting our homes periodically.

Comfort is a different issue, that really doesn’t have a price tag. I have found that people living in a home they think is uncomfortable do many things to obtain comfort. They continually adjust the thermostat, they add electric space heaters, or window air conditioners.  These are expensive. They sell the home and then the next owner can be uncomfortable.

The first example of comfort came when I was doing my due diligence in starting my career in Energy Efficiency. I attended a seminar at a local home show on Energy Efficiency. The presenter related one of his experiences with comfort instead of purely cost reductions.

He had done some duct leakage testing in his own home and found the duct leakage was a major contributor to the cold bedroom of his daughter.  This led to an easy fix of sealing the accessible duct work. For this example, I would thank Jeff Boone @JFBoone of Northstar Comfort Systems.

Information I Need

John points out a, new to me take, on the house is a system. Building Science has always considered the house to be one system. If you change an item, something else will probably change.  The corollary to this is ‘First, do no harm!’. If you make or recommend a change, you should look at what else may change and take steps to ensure the reactions to your first change are positive for the house and the occupants, not negative. Examples would include:

  • Adding insulation to one side or the other of an exterior wall could change how the wall dries. That change could cause mold and decrease the quality of indoor air quality.
  • Doing air sealing work can make significant energy savings. Decreasing the ventilation through infiltration could create a dangerous situation, if the decreased amount of fresh air will not support the needs of the hot water heater and furnace.

John expands on this by adding the concept that a house as a system can be specific to a type of construction. A house built with techniques in common use in 1800 would have the system effected if the improvement used some technique that is in common use today. This is something I need to know more about.

  • How different do the original construction techniques need to be for this to become significant?
  • Is it something that that only happens in a 200 year swing of construction techniques?
  • Is it something that occurs in applying today’s techniques to a ballon framed Victorian?


The goal of this post was to advance the conversation #DER with some basis and examples of the proposed definition of Deep and to set out that energy efficiency improvements are never a goal in and of themselves.

It is not a good idea to do an improvement that will not last. It is not a good idea to ignore comfort issues. We must protect the occupants of the home from hidden dangers, such as carbon monoxide, or water damage. When improving the energy efficiency of a home, it is very easy to improve the durability of the improvement with choosing the right material, and including the protective installation, for example flashing or a drainage plane around insulation.

I look forward to following the #DER conversation in more than 140 char bites.


8 thoughts on “A Twitter Conversation – Moving Along, Part 2

  1. Pingback: Deep Energy Retrofit’s – The Conversation | The HTRC: Homeowner's & Trades Resource Center

  2. Sean @ AlaGBS / SLS Construction

    Very nice follow up piece John & as the semi-official cat herder / moderator I also added a link in the update section.
    In regards to the Info I Need area /200 year swings, etc… the catch is not really the age, but how it was built. Many older homes have great drying potential so it didn’t really matter if they didn’t flash the windows, etc… The biggest issue is people coming in & filling the cavities with cellulose or some other material and turning those areas into a big spounge.
    Even with relatively newer built historic houses (where they might have used skip sheathing & felt paper) the issue can still arise & one needs to watch out for bulk water issues.

  3. John Poole

    Hi John,

    This is a great posting and I’m not sure how much justice I can really do it by posting a comment here, but I’ll try to add my $0.02 to some of the issues you highlight; others, I’m simply not be able to.

    1) Regarding cost effectiveness, I agree that a 99 year ROI (as opposed to, say, a 14 year ROI) is not going to be looked upon very favorably by homeowners. And I think this is one of the issues with DERs — most are too expensive to yield a ROI within a reasonable time frame. Certainly not within the current owner’s life time, and furthermore, a DER doesn’t strike me as a sexy capital improvement that will fetch a significant resale markup (maybe for some folks, but I bet not for most). The link to the green goddess article, and her link to Martin Halladay’s musings on the cost of DERs are worth reading in this regard.

    2) As far as climate and the definition of DER goes, my original supposition was that a 30% reduction in a severely cold climate would cost significantly more to realize, all other things being equal, than a 30% reduction in a relatively mild climate. But you might very well be right that adjustments for energy costs could still make the ROI the same in either case. This point might not be worth pursuing any further unless some one else has a good counter-point suggesting otherwise.

    3) Regarding comparisons of contemporary versus past building techniques, and how to best deal with the differences, I think this is an extremely broad area that would take much time to research and compile, but nonetheless, might certainly be worth the effort, and of much benefit to tradespeople who are new to older buildings. But in a nutshell, I agree with Sean’s assessment that age isn’t so much a factor as the styles of construction themselves.

    Now, here’s a little bit more insight from the houses of Derby CT (and other parts of New England) that might be of some consideration, though far from being a complete treatment of how older homes functioned differently in terms of the “house as a system” point of view:

    The earliest N.E. homes were built mainly to provide shelter from a hostile environment. Many of these old timber frames were notoriously overbuilt. Part of this was because of the ready availability of old growth trees (most of which had already been depleted back in England by that time), but also because of a desire for protection against harsh elements (winters were known to have been much more severe back in those days), as well as potential attacks by Native Americans and the Dutch, who were competing for territory in parts of New England with the English.

    Many of the earliest homes survived so long because of their over-built construction. For example, I’ve heard many tales of homes where the bottoms of timber posts were almost completely eaten by termites, but the houses still stood, because of the strength of its sheathing alone (e.g., 2″ x 18″ white oak planks, not OSB! 🙂

    But these houses were also leaky as sieves. This wasn’t necessarily intended by design, but it also wasn’t much of an issue either. The earliest homes relied on fireplaces, of course, and the single, massive amalgam of fireplaces and chimney column acted as one giant thermal mass that projected radiant heat outward into the rest of the house. (You know how a fireplace works: If you you’re right in front of the fire, you’re warm. Walk just a few feet away, and the cold quickly hits you). On the coldest nights, occupants probably didn’t care too much about drafts, because they were huddled on top of the fires, any way. (Although we do know that they made efforts to prevent drafts — by using heavy curtains, wing-back chairs, and even primitive attempts at air-sealing using rags, oakum, etc. But air-sealing was only done where drafts were major and very obvious).

    Now, although some warm air was still carried upwards by stack effect, they didn’t have a situation where warm, moist air was being actively circulated all around the house. So there wasn’t very much moisture infiltrating wall assemblies from the inside. Furthermore, any moisture infiltrating walls from the outside was quickly expelled by all that radiant heat from the central chimney column, or blown out by the winds and cooler, dryer, denser air that normally followed a rain storm. As Sean points out, major penetrations were never flashed in many old homes, simply because there was no obvious need for it).

    This was pretty much how houses were built pretty much up until the civil ward. (That early tendency to overbuild pretty much subsided by 1750 or so, when frames started to get thinner and more accommodating of plastering-over or being cased-over in fancy wood trim, etc). After the civil war and reconstruction and recovery, there was a boon in industrial development, and stud framing came into being in the late nineteenth century, and fossil fuels began to play a role in heating homes. But the builders who pioneered the use of stud framing were still apprehensive about this new technology, so they also overbuilt. At least at first. And homes still continued to be leaky, with radiant heat from wood and coal stoves now driving out the moisture. Again, this is why so many homes from 1870-1920 or so, still managed to be quite durable. I’d say that it wasn’t until fossil fuel use began to become unstable price wise (1940s-1960s), and folks started to add insulation, etc., that the real durability issues started to emerge.

    4) Durability — You bring out a great point, in that retrofit work done in the name of energy efficiency alone still needs to be undertaken as an exercise in enhancing a home’s durability. (At least, I believe that was your main point). There’s an old roofing / flashing adage that I love: “Think like a rain drop.” Perhaps “think durability” is an equally important mantra for anyone planning an energy retrofit. The more that sort of mindset becomes ingrained and internalized, the better results we can expect from retrofits.

    That’s all I’ve got. Like I said, this is a wonderful post, John, and I really like the idea of having these multiple, successive posts outlining the discussions on some regular basis. Makes it far easier to digest what’s going on. So thanks very much.


  4. John Poole

    Oh, BTW. The reason why I mentioned old growth trees having been depleted in England, in my comment above, was to emphasize the fact that housewrights trained in England who came to the colonies to work had something a field day with all the towering, straight, branchless trees they found here. So they went nuts and built very substantial structures in the New World, using very long, continuous timbers in most cases, something they never could’ve enjoyed doing back home.

  5. John Nicholas Post author

    OK! I have a much improved understanding of the building techniques that you run into with those 200 – 300 year old homes back in Derby, CT. Sturdy, over engineered Timberframed structures. Compared to our stud framed construction. I also relate to the lack of old growth trees in the mother country then coming here. The elements and the original settlers also would create some unique finds within the walls.

    My wife was born and raised in a farm house that parts dated to 1867. It was a stud framed construction, one room, one story. Her dad once showed me the inside of a wall, the studs were varied sizes like 4 x 8s. All hand hewn or if lucky sawn. Stacked stone crawl space walls. No room to insulate the walls. They were stuffed with bricks. Protection from the Indians.

    The information, from Sean and John, in these comments is very helpful to me. I would agree that the age of a home is less of an indicator then the type of construction for differing techniques.

    John, one question. You mention 1750 in one sentence and then immediately move to post civil war and the reconstruction period. Some clarification would be helpful.

    In terms of durability, that is a lot of the change from V2 to V3 of Energy Star. The addition of the water management checklist is almost 100% durability issues. I would posit that it is kinda silly to install insulation in a new house or an older one, if you do not protect it.

    Sean, when you mention skip sheathed, are you referring just to roof decks or does that also mean walls?

    Thanks Guys!

  6. John Poole

    Hi John,

    Yes, many interesting things turn up in very old walls. One of the most interesting are “concealment shoes”, which means an old pair of shoes plastered into a wall (or mortared into a fireplace or chimney) that were felt to ward off evil spirits. These are often found when renovating or repairing these very old homes.

    In New England, there were three distinct “waves” of early colonization that also had distinct architectural styles associated with them. The earliest homes (1620s) were often no more than crude huts. Around the late 1630s or early 1640s, traditional two bedroom, two story English style homes started to appear. This was the norm until around 1670-1700, when the salbox with the “lean-to” rear-roof came about as a means of having a full kitchen in the rear of the house (the Mansfield house is a saltbox). Many saltboxes were actually conversions of older homes.

    Then around 1710-1740, full two-story homes without the lean-to rear roof began to be built, as the colonists were getting wealthier at that point, and wanted to build larger houses. These were no longer English style homes, but were of a distinctly American design. By 1750 or so, houses were no longer being built with quite the same massive timber framing as the much earlier homes. The use of large summer beams in the second and attic flooring systems completely disappeared, and timbers were cut with the intention of being either plastered over or wood-cased, whereas earlier timbers were carved and chamfered. Joinery was also much simplified (the classic English tying joint was long gone). Homes with a central hall way and two large chimneys at each end began to appear, and houses were more ornately decorated inside.

    Much of this later style of construction (called 3rd period, at least here in Connecticut and I believe also in Massachusetts) continued until the Federal Period (1820 more or less), and then the Greek revival period, which I believe took us more or less up to the time of the civil war. But timber framing was still the predominant framing method until around the 1860s-1870s.

    By the way, many very old timber frames had stud walls, although the studs were not structural. They were built as a nailing surface for the exterior cladding, and also often filled with mud and straw or sticks (waddle and dawb) as a crude means of insulation). On the interior, the studs supported wooden lath for plaster.

    The other style of construction was the plank house, where large 2x vertical planks were fastened to the major timbers and formed the exterior sheathing. Cladding was then nailed directly to these planks. On the inside, a nailer or furring strip was nailed down the center of the vertical planks (sometimes all 16″ o.c., believe it or not) and these strips supported the lath for the construction of interior plaster walls. This type of wall was extremely strong and the vertical planks made for a very stiff structure. Both the Mansfield and Hawkins homes are plank houses.

    I am not surprised that your wife’s childhood home had stud walls with those large studs (e.g., 4×8). I believe that during this period, timber frame construction was beginning to evolve into stud framing, but stud framing didn’t really take off until the 1870s when saw mills became more widely available. And I’m sure there were many local variations of all kinds of framing techniques and patterns that I would know nothing about.

    But my point about the civil war was that many things, including construction methods, remained quite primitive until that time. At some point following the civil war, industrialization picked up, and wire nails came about, and the proliferation of sawmills made the creation of dimensional lumber easier, so stud framing began to take off around the late 1860s-1870s. Balloon framing came about then, as well. That was my main point.

    Here’s an article I wrote a while back for Building Moxie that you might like. It’s about square nails. It covers their history, and also describes their modern equivalents (which are still manufactured today, BTW, you just have to know where to go to order them):


    Here’s another article that appeared a while back in FHB magazine that I also think you’d find fascinating, even you haven’t read this already. It covers the history of the American home and in particular, the evolution of residential energy from the earlier Colonial days to the present:


    Hope you found this information helpful!

    ~ John

  7. Amy Good

    Hey…reading this post has been interesting as a 1930 farmhouse owner with many drafts, as well as regarding my position with a timber frame company.

    So, there were many, many different kinds of timber framing used in the historical days. Some are mortise and tenon, while others may have been post and beam. The connections and strength are different as far as structural integrity. I’m not sure that makes a huge difference for your calculations.

    Today, we find ourselves needing to rebuild certain structures that have been poorly maintained. That same structure will often not pass engineering…even though it stood the test of hundreds of years.

    Also, with modern timber framing we have the capabilites of SIPs (Structural Insulated Panels) or built up roof/walls, which I believe creates a better envelope than “back in the day”.

    I must run, but plan to follow this conversation as best I can.

  8. jb @BuildingMoxie

    John from Derby (1 of 2) . . . ha! thanks for including me here, but I will point out straight away that my interest is purely that of an audience member. I will admit that I know most of the players involved and despite the obvious entertainment value — I do find it to be a facilitating question. As I think Allison posed it — DER & Historical Preservation, can they live hand in hand? I feel like that I have said this previously (in other circumstances involving *cough* Sean), I am just thankful for a platform like twitter and it’s ability to spark such a conversation.

    That said, I very much appreciate the passion that John from Derby (2 of 2) puts into this/his study. I myself (average homeowner) tending on the side of not so much preservation, but historically sensitive and (cost-) sensible improvements. ha! anyway — here to learn. And it is like an onion. Busy reading just to get here today. Cheers to all involved and especially you John for sharing your thoughts. ~jb


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