Deep Energy Retrofits, Historical Properties, and the Conversation

Sean,

Thanks for keeping this conversation rolling with your own thoughts and impressions. Nice write-up. It sparks quite a few additional thoughts and reactions on my part, so I will attempt to communicate those here:

First, I think you put the whole topic in good perspective by tying it back simultaneously to both the IECC, and the NPS guidelines. Many folks who have gone out on a limb to define what “DER” means often do qualify it in terms of “some percentage over a comparable building conforming to current energy codes”, which might, in some cases, make it all that much more challenging for an older building (e.g., you’ve got to go all the way out to 90% over actual building performance to hit 30% over a comparable, modern building’s performance; but then again, in the case of an old building, it’s often easy to achieve some large successes early on, followed by much detailed, fine tuning).

You also provide an important reminder that ultimately this work is being done for the home or building owner and needs to meet their objectives. And I’d agree that many preservation folks pontificate on the merits of the procedures being used to achieve those goals, while somewhat losing sight of who controls the purse strings, and who really owns the project. But I think the reason why the historical preservation folks get so torqued over this is because of a perception on their part, which I believe is often correct, that many homeowners aren’t always aware of what treatments might be good or bad for a very old or historic home, or what their options or decision points are, or what preferable options might consist of.

This is probably an unfair and grossly out-of-scale simplification, but in some way, DERs are being advocated for very old and historic structures in a manner not all that dissimilar from the way vinyl replacement windows were over the last few decades. The salesman shows up and says “I see you have a few horribly deteriorated wood windows, and most of the rest are painted shut. We can fix all that in one day, plus solve all your energy efficiency problems by 50% by replacing them all with new vinyl ones.” The owner signs the contract, hands the salesman a big check, all the windows get replaced (when only two or three actually needed replacing; the rest simply needed maintenance), and ten years later, seals are opening, meeting rails no longer meet and cannot be locked, and sash lifts are breaking off in the owner’s hand (exactly what’s happening today in my mom’s house, in fact). Meanwhile, colleagues of mine in the Windows Preservation Standards Collaborative (which I’m a part of, but don’t have the kind of time I wish I had to participate) have done extensive energy testing on older wood windows and found that, with reasonable maintenance, weatherstripping, and storms, the old windows they tested exceeded IECC 2012 requirements, at not nearly the cost of disposable vinyl windows. (The bulk of these results are supposed to be published about two months from now).

Again, that was probably not a fair comparison, since, as you pointed out, a DER is far more than a simple, repetitive removal/re-installation project, but I hope this comparison at least helps others out there to better understand the preservationist’s mindset to some extent: our general concern is that many homeowners and many contractors don’t always have the full story on alternatives, and that there are strong advocates out there pushing for just one way of doing things. This is why I get so bent out of shape when Peter Troast says that designating historic homes as “hands-off” from DERs “condemns them to hospice.” No one in the preservation community is opposed to extreme energy reductions; no one wants to condemn older homes. We just think there are better methods than what’s often promulgated, or included in the popular definition of what a DER is.

Your criticisms regarding in-kind replacement (use of same materials), and reversible treatments, I completely understand, but don’t totally agree with. Here are my counter arguments:

There’s an active market these days in salvaged and reclaimed materials, which, for better or for worse, exists precisely because of all the tear-downs and replacements going on. Granted, reclaimed materials are not always convenient to obtain, but in the case of precise repairs for very old homes, I for one, always insist on going this route. Were I doing a Dutchman repair on an old wooden sash, for example, I wouldn’t in a million years opt for “white wood” (wet wood?) from my local Home Depot. Rather, I’d go to the trouble to acquire some old growth wood of the same species for that repair, so the repair would be that much more durable and weather resistant. Common wisdom seems to say, however, that since old growth wood is no longer obtainable, skip the repair and just replace the entire window with a vinyl “replica” that might, as a whole, last 1/4 as long as a properly done Dutchman.

Now here’s another, more personal example: Before I acquired the Mansfield house, a number of clapboards at one gable were deteriorated and in need of repair or replacing. But the remaining siding was generally OK. Had I owned the house back then, I would’ve repaired bad areas with architectural epoxy, if possible, or would’ve replaced any un-salvageable boards using reclaimed old growth wood (even if that meant completely ripping and shaping new boards). But the contractor who was doing the roof at the time bundled in an offer to repair the gable siding along with the roofing job, which the previous owners agreed to, without even discussing with him how he’d approach it. What do you think he did? Well, he replaced ALL of the old growth gable siding with Home Depot -grade wet wood, of course!  So none of the durable, denser, old growth siding remains on that gable. For want of a few damaged old-growth boards, the entire gable exterior was replaced with inferior wood. And no one involved at the time — neither the owner, nor the contractor — even considered that fact. (Sounds a lot like the replacement window scenario I described earlier, doesn’t it?). This is what I mean by the stark differences in mindset about what’s acceptable when working on older properties, and why those folks who are preoccupied with preservation can get so worked up about what treatments are largely viewed as being acceptable.

Regarding treatments that are reversible (sometimes called “re-treatable”), this is not held as an “always-must-have” goal for all work, but is one of many considerations weighed-in with other criteria, frequently as part of a decision making process or overall planning of work. No preservationist who knows anything would advocate blown-in cellulose or fiberglass in an old wall purely on the basis that it’s “reversible in principle” alone. Most understand that it really isn’t a reversible treatment, and furthermore, a durability risk if there’s water/moisture infiltration in the wall. But replacing a wall with a SIPS isn’t even reversible in principle.

What might preservationists consider to be reversible energy-related enhancements to an historic property? Here are a few examples (these are just broad illustrations on my part, not necessarily complete or accurate specifications):

1) Restoring and weatherizing old windows and air-sealing their perimeters, certainly. Conventional wisdom, and the way most DERs are performed, often call for complete replacement of existing windows. Yet my friends have demonstrated that old windows can be made to exceed IECC 2012 requirements.

2) Insulating an attic floor by air-sealing penetrations, installing an air barrier, and filling the joist bays with rockwool batts, which have an R-value that slightly exceeds that of fiberglass, are resistant to moisture, have low environmental impact in their manufacturing, don’t have the moisture, settling, or leveling or fluffing issues of blown-in insulation, and can be accurately scribed to fit around penetrations and irregularly-shaped joists (in the case of really old timber frame homes). Maybe top it all off with a foam board on top of the rafters and under the floorboards to reduce thermal transfer by the rafters. (And, of course, the attic needs to be positively ventilated). But current DER philosophy usually says the only effective way to insulate here is to encapsulate the rafter system in spray-foam, or replace the original roof with SIPS.

3) Air-seal an old wet-laid foundation wall or chimney column by re-pointing it with the same mortar that was originally used to bind it. (What a novel concept! Few folks remember these days that lost art called masonry). Insulate the interior foundation wall with rockwool (again, because of its R-value and moisture resistance). You’d have to build-in a stud wall to hold the rockwool in place, of course, and although not easily reversible, you could still un-do it at some time in the future, if needed. Contemporary DER philosophy says to completely encapsulate the wall or an unused chimney column in spray foam, making historical details no longer accessible to future historians.

4) Some friends of mine at Historic New England needed to air seal and insulate the top of an old chase. They did so by employing a little creativity. They used tape and Tyvek to construct a “pillow” and loaded it with fill insulation (I forgot exactly what they used for the fill). With some effort and trial and error, they finally managed to get the pillow to fit the top of the chase perfectly and snugly. They had both a reasonable air seal and a thermal barrier in one fell swoop…a reversible treatment achieved using modern materials. Conventional thinking would’ve called for wood or sheet metal work, followed by caulking and/or spray foam.

Anyway, sorry to be so long winded, but this is a topic I can’t easily put to rest. What I strive to do here, more than anything else, is to get energy and DER advocates to understand why preservationists object to the methods and materials of DERs as they are currently being promoted; that they have good reason to object to present day strategies for implementing DERs, the same way they have good reason to object to wide-scale window replacement with disposable/non-maintainable manufactured replacements.

I think that divorcing the definition of “DER” from any particular implementation strategy would go a long way toward getting preservationists more comfortable with the concept (I feel that the concept itself is valid, and quite frankly, am a proponent of it myself, just not a fan of how many folks are currently promoting it). Also, I believe that empirically demonstrating that (mostly) reversible treatments, based on more traditional work methods, would also go a long way in this regard. Unfortunately, progress in that area is slow going, but it’s getting there. Hopefully, the pace will pick up as more results and methods get written about and published, and a certain amount of critical mass and mindshare begins to build. I personally hope that this conversation of ours will ultimately contribute significantly to the building of that mindshare.

~John