A High Performance Home is Defined by the Process, Not the Products
Geothermal heat pumps. Tankless water heaters. Spray foam insulation. Because of all the hype around ‘green’ products, it’s easy to focus on the details and miss the big picture.
Geothermal heat pumps. Tankless water heaters. Spray foam insulation. Because of all the hype around ‘green’ products, it’s easy to focus on the details and miss the big picture.
One problem with getting sucked into the green product hype is that some of those products are outright scams (e.g., power factor correction devices) and some are overblown (e.g., foil-faced bubble wrap duct insulation). You’re mostly just enriching the companies that sell that stuff to you if you fall for it.
In the case of legitimate green products that make your home perform better and save money on your energy bills, it’s possible again to get little or no benefit from them. For example, I’d much rather have a 13 SEER air conditioner on a great duct system than a 19.7 SEER air conditioner on a typical duct system.
If you’re buying, building, or involved in any way with the creation of a high performance home, here are some guidelines to help you not lose sight of the forest for the trees:
- Get a home energy rater involved to do energy modeling of the house before you start building or renovating.
- Focus on the building envelope. Make sure that the insulation and air barrier can really do their jobs so you minimize the amount of heating and cooling the house needs.
- Make sure the HVAC system is designed well, installed properly, and commissioned.
- Put in a high efficiency or solar water heater, but don’t forget about the distribution system. Minimize the length of the hot water lines by clustering bathrooms, kitchen, and laundry.
- Use natural light, compact fluorescents, and LED bulbs to reduce your lighting costs.
Let me state this again: It’s not about the products. It’s how it all works together that matters. I know that mastic, caulk, and insulation installed to grade I aren’t as sexy as geothermal heat pumps and photovoltaic modules, but the basic design details, material choices, and installation methods are actually a lot more important than the trendy ‘green’ products.
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Allison, if I may add: there
Allison, if I may add: there are many products out there that are valuable under certain circumstances and scams under others (radiant barriers for one). There are also many products whose value is contigent upon the installers care and experise (foam is 95% mix and application.)
“Greenwashing” has become so commonplace with ridiculous claims of (effective) R-Values and ROIs. The average homeowner hasn’t a clue at what to look for, which reinforces the value of a Professional (Resnet or BPI certified)to assist in design and implementation.
AB, as always you hit the
AB, as always you hit the nail on the head.
Your last paragraph sums the issue up nicely. It is not so much about “the shiny things” but more about does what you have work? So much of the fancy equipment that marketers try to jam down our throats will not work to its full potential or not at all if the basics are not done correctly.
It’s the ENVELOPE people. Your homes’ performance will live and die by the quality of your envelope.
To all of the “greenies” out there, it does not matter if you install bamboo floors, organic cotton drapes, use low VSC paint and the like if the “foundation” of the home is not solid.
It’s not rocket science, it’s building science. Make sure the basic systems and assemblies work before you start throwing green paint on it.
I made the same point in my
I made the same point in my comment at Zeller’s Green blog in yesterday’s NYT. In particular, I was critical of the passive house project Zeller described in Sunday’s NYT (Beyond Fossil Fuels) as sending the wrong message. See comment #10:
http://tinyurl.com/3xhp677
Paul, you may indeed add your
Paul, you may indeed add your comments, and I welcome you back to the EV blog. It’s been a while since I’ve seen you here.
Yes, some products can be both scam or valuable addition to a building, depending on how they’re used. It’s all about the process, not the products.
Not only do homeowners need help with this but so does just about everyone else in the building industry it sometimes seems. Many builders, trade contractors, and even energy raters have fallen under the spell of ‘green’ products, so that makes it doubly important for those of us who understand building science to spread the word – It’s the process, not the products.
Justin, I couldn’t have said
Justin, I couldn’t have said it better. The envelope definitely comes first because it determines how much heating & cooling a house needs. So, make it as small as possible, and then the equipment becomes less important. Do the ducts right, and a standard efficiency HVAC system can outperform a high efficiency system with crappy ducts.
I love your line, “Make sure the basic systems and assemblies work before you start throwing green paint on it.” And, as you say, bamboo floors and low VOC paints don’t make a house green.
David, thanks for your
David, thanks for your comment here and the link to your NYT comment. Great points, and a lot of overlap with what I said here.
I’m actually a fan of the PassivHaus program, though, because they really push the envelope, literally. I’ve never been involved in a PH project and don’t know that I’d go all the way for their certification in my own home, but I like the idea of drastically reducing the heating & cooling loads. You’re absolutely right, though, that that shouldn’t be your only goal and that the design phase should include looking at cost effectiveness.
Allison–I agree 100% with
Allison–I agree 100% with you on this post and it’s one of the most articulate on the topic I’ve read in a long time.
BUT….
Sad as it is, housing consumers want things. Granite counter tops, tiled bathrooms, Viking stoves. For the slightly more enlightened, thing lust extends to green bling: solar, geothermal, LEED. At the edge, we’re seeing some evidence that the bling is extending to things that matter. I got invited recently to see a very proud neighbors’ 12″ offset stud walls. (Nevermind the HRV return ducts in the unconditioned attic.)
The question for all of us, though I believe in it with all my heart, is whether process sells. Some productization of the outcome of proper building science process seems like it’s critical. The all-in-one passive house HRV/Furnace that takes up half a closet, air flow via an ERV/HRV system that you can feel, a heating bill, a prominent energy monitor.
Pride is so inherent in everything about our homes. Process is critical, but giving homeowners the ability to show off things that matter is too.
I was nodding my head the
I was nodding my head the entire time I was reading this.
The biggest problem I see is that people who get reeled into thinking that a radiant barrier is a cure-all will then be less likely to believe that things like air sealing can actually help. It degrades the entire energy efficiency movement when promises are made and fail to live up to expectations.
I agree with this artcle. I
I agree with this artcle. I would rather design my building envelope framed with two by six studs and fill the wall cavity with R nineteen and back that with R four foam finished with brick. With R thirty eight in the ceiling. Than invest in technology. Unless it is solar space heating. And then I might consider a heat pump. But I would use a heat recovery ventilator system. Solar heating can pay for itself many times over within it’s rated life time. And besides. Winter heating is the greatest year round home energy demand.