What is a Deep Energy Retrofit? Experts at the NESEA Conference Respond

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By Victoria Scanla... - March 11th, 2010

At the NESEA Building Energy 10 Conference in Boston, great minds have been busy discussing the best ways to build (and rebuild) better buildings. And talks range from covering mechanical details to virtual collaboration in design. Still, one recurrent theme has dominated the conference. "Net zero" was the buzz word a couple of years ago, says Passive House guru Jamie Wolf of WolfWorks. "Now, it's 'deep energy retrofit.' " As much as the concept is gaining broader recognition, there are varying definitions about what it means.

So, we figured we'd ask attendees and experts: just what is a Deep Energy Retrofit?

Jamie Wolf: "We're aiming to reach a threshold of energy use. We say 70 to 90 percent energy reduction of a bad building. It's dramatic. That's why we use the word 'deep.' Anybody who is going to embrace what it takes do a deep energy retrofit has got to be thinking way beyond personal benefit. At the end of the day, we wouldn't be here if we hadn't stared carbon in the face. We looked at our buildings and said, 'we'd better get a move on.' "

Cador Pricejones, project manager with Byggmeister, Inc., and owner of a (nearly finished) deep energy retrofit in Somerville, MA: "A lot of people define it as a 75 percent reduction in energy. But I don't think it's too helpful to get hung up on the numbers. Whatever you can do is a help, a long as you take a whole-house approach. You can phase it, or do it all at once. Just do as much as you possibly can to the entire house."

Ken Neuhauser, Building Sciences Corporation: "Deep energy retrofits are hard. They are not simple, quick or cheap. I would define them as taking an existing building and reducing its energy use by 50 percent over a new construction, code-built building. If we said 50 percent reduction over the current energy use, that would be easy. But if it's a dog, and you reduce it 50 percent, it's still a dog. We can do better than that."

John Livermore, Livermore Energy Associates: "I would define a deep energy retrofit as … a project that involves super-insulating the building shell, and achieves over 50 percent energy savings."

Sean Jeffords, Beyond Green Construction: "A deep energy reduction is.. a comprehensive renovation or remodeling strategy that when done properly will substantially improve the comfort, durability, health and air quality of a home or building. These efforts should provide a minimum energy use reduction of 50% or greater to receive DER status."

Linda Wigington, founder of ACI and the 1000 Home Challenge: "Retrofits are what people do when they thicken the walls. We're talking total energy reduction. You're not going to get the 75 to 90 percent energy reduction we're aiming for in the 1000 Home Challenge with retrofits. You're going to reduce heating use—and you could reach 75 percent less—but you're not going to affect other energy use. To get really deep energy reductions, we need to look at how we live in our houses. How we live in them matters a lot."

What do you think? And....as Ken says, percent of what?

Comments

I agree with a point Linda made: "we need to look at how we live in our houses". We can make all the physical changes in buildings, but if we don't change our behavior we won't get very far. Many people live in homes that are certified as "green" that are 5-10K SF, have dozens of energy vampires, leave lights and electronics on all the time, and open windows and doors without turning off HVAC systems. Unless we can change behavior, most likely through higher energy prices, we can only achieve so much efficiency through structural and mechanical changes. Posted by Carl Seville on Mar 12, 2010 7:53am

>>we need to look at how we live in our houses. How we live in them matters a lot.<< I agree. At our 1899 house in Portland, Maine, we wear sweaters and hats indoors all winter. Our fuel oil supplier always asks why we never use much oil (about 25% of what their other customers use). What high-tech device do we use? We use the old-tech original equipment devices that came with the house, like the doors, we simple close and open the interior doors and only heat the rooms we are using and never heat the halls. We simply use the century old roller shades on a daily basis to improve the energy efficiency of our windows by 10%, use the curtains and get another 5%. You can spend your money on electro-gizmo green if you want to save electricity. Instead of participating in excessive consumerism we use old-fashioned common sense: turn off and unplug what you are not using. If you have to do some serious reading get up with the sun and sit in a chair next to the window. "ooooh, but I wanna stay up and watch Jay Lenno, and sleep late in morning." Well, get over it! We get mad when the big banks grab more of our money than they deserve. So, we need to learn to be less grabby ourselves when it comes to flipping on the light switch or bumping up the thermostat. take care, do good works and keep in touch John by hammer and hand great works do stand Posted by John Leeke on Mar 12, 2010 5:42pm

Your question addresses what I see as a fundamental problem in the conversation right now. What constitutes deep? There is a second and perhaps more important component that is missing and that is the word “safe”. Energy efficiency retrofits are elevating the danger of home occupancy for our citizens. But back to your question.. We currently don’t have an agreed on metric to help us clarify and quantify what a deep energy retrofit is. Without a starting point or an end point it does little good to throw around percentages. Getting a 1880 home to HERS 50 is possible but invasive and expensive. The primary energy load in terms of dollars for an old home in a cold climate is heating, but is the primary carbon load also heating? The passion for energy efficiency is often overshadowed by a misguided attempt to sell energy efficiency. The unholy marriage to “dollars and cents savings” has led us astray. The measurable, and therefore manageable, imp is carbon. The act of releasing millions year old carbon (vs hundreds year old carbon found in trees) is what has our PHDs all nervous about. So why not start talking about it? What is the goal of a deep energy retrofit? It is to bring a home’s carbon emissions down to a sustainable level safely. If we start there, then the devices we employ to reach that goal may be considerably different. Consider this. If we took account of the entire US housing stock’s carbon responsibility, new and old, and set a cap on what that total amount could be it would allow us to treat the housing stock as a portfolio. We could see if it is in fact our historically beautiful but notoriously leaky homes are the problem or if is the homes of the 60’s-present with their AC systems, recessed lights, oversized spaces, and myriad switches. We could develop strategies that allow us to retain our older housing stock with its great bones and aesthetic character while developing new housing stock that is highly efficient. We would be forced to address fuel source (so critical in my opinion!). We would evaluate device loads, and along with that lifestyle. Some homes may discover that they can reduce their carbon contribution by 50% without spending a dime. I’m just saying before we rush out to skin every pre-war home in 4” of XPS that we take a step back and figure out what the heck we are trying to achieve. Posted by Michael Anschel on Mar 12, 2010 7:34pm

To hear Jamie Wolf and Michael Anschel talk one would could easily conclude that energy efficiency is poportional a building's carbon foot print. Normally Michael Anschel and I are at least in the same chapter of the book on things, but in this case we might be lucky to find ourselves within the same book jacket. If carbon is the metric of choice of energy efficiency (and therefore the gauge by which we measure the "deep energy retrofit") then the tens of thousands of old 1950s craftsmen homes in portland, with their old 1950s electric furnaces, deserve at least a HERS 50 rating because their carbon footprint is zero. The bulk of Portland's power comes from Columbia River Hydroelectric power; the balance from a nuclear power plant on the Columbia. We can also assume that the old 1887 victorian home I examined last week for a potential "deep energy retrofit" also not need concern itself. Though it burns nearly ten cords of wood a year, if like most experts, you agree that wood heat is carbon neutral, (and it seems Michael Anschel does not), then since it gets a majority of its electrical power from hydroelectrc and much of the balance from a hog fuel (i.e. wood by products—bark, sawdust, etc.) fired power plants, its carbon foot print is very small. That despite the fact that, like the old craftsmen homes, it doesn't have a scrap of insulation in its walls, doesn't have dual pane windows, and can't even claim to have weather stripping around the exterior doors. Nothing to worry about. The carbon footprint is neglible, therefore all is well. I think net energy consumption is a much more universal and practical metric. Not price—that moves up and down in response to market forces. Rather, an index based on the building's use or production of electricty and fuels using industry standard measures for each. Such a metric would allow a fuels neutral method of analyzing a building's performance and the effects of any proposed upgrades or modifications, free of market forces and the political biases of the moment. And that, it seems to me, would be a much more accurate, universal applicable, and less politically charged metric than one based on carbon. Posted by Michael Matson on Mar 13, 2010 10:38pm

Thank you, Michael Matson. Our metric should not be simply carbon emissions (or footprint, in the popular lingo). I happen to believe climate change is a serious problem, but for the past ten years, I've feared that peak oil may get us first. If that is indeed the case, then reducing energy use, no matter the source is more important than reducing carbon emissions. If you're not familiar with peak oil, go to www.aspo-usa.com or www.theoildrum.com to find out about it. That $4 per gallon gasoline in '08 didn't come out of nowhere. Posted by Allison A. Bailes III, PhD on Apr 2, 2010 9:31pm

What is a Deep Energy Retrofit? Experts at the NESEA Conference Respond

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