green building

November 27, 2011 3:00 PM

Recently gotten interested in energy-efficiency design; that is, super insulation, ICF walls, triple-pane windows, with heat recovery ventilation. But (aside from experienced practicioners) discussions seem to go 1. they are converts, "green" is a religion, everything has to meet these sometimes costly/untested standards, and that trumps pocketbook costs. 2. skeptics, conveniently and defensively dismissing green building because it adds too much to the cost, and payback time will never justify the up-front costs. Help me to understand the ADDED costs of achieving higher levels of energy efficiency, going beyond the existing Building Code energy requirements, (e.g. using German triple-pane windows instead of domestic double-pane, how much more?) and how do you figure the spread out to the building's future use? Part 2 is that cost and efficiency are not the only metrics involved here. Air quality, landfill waste, health, manufacturing waste, etc are part of the equation also. How does a Builder, Architect or prospective homeowner, new to this shifting landscape, start to understand, and explain it?
posted by ebesan to Home & Garden (11 answers total)

There is no definite answer, because you can't predict how much energy will cost in twenty years.
posted by Chocolate Pickle at 3:13 PM on November 27, 2011

There are other assumptions, too, like the expected lifespan of those windows or whether you are going to do a major addition later that will change your hvac needs. My perspective as a homeowner who cares about efficiency is that this stuff is complex, especially if your budget is limited or if you try and balance the overall impact of efficiency gains vs the environmental cost of producing and transporting new materials.
posted by Forktine at 3:40 PM on November 27, 2011

I've done some home renovations, and I've paid attention to energy-conservation building practices over the years. Builders use what's available at the lumber store, Lowe's, Home Depot, etc. They don't handcraft a home; they use available materials and components, and the form of buildings is often dictated by what's available. Many homes have proportions divisible by 4 or 8, because lumber, sheetrock and plywood come in 8' sections, and it creates less waste. Windows and doors are stock items. They probably use pre-made roof supports, so the pitch of the roof is pre-defined. This is not new; many old (1910) houses in my town have similar woodwork, because it was popular, and in stock. Everything that requires custom building and special components adds a lot of upfront expense.

Systems have to work together, or you get tied to a vendor and can't get parts, or a manufacturer goes under, and you can't add on, which seems to be an issue with solar installations.

Buildings have to be built according to building codes. The people who design and manufacture building components are concerned primarily about sales. New homes are built to be attractive to sell, not necessarily efficient to operate. Consumers haven't demanded really energy-efficient buildings, at least not if they'll cost more.

To calculate savings, you need to understand degree days, for both heat & a/c. If adding triple panes will reduce heat loss, it makes a bigger difference in Maine in the winter than in No. Carolina, but in Florida in the summer, will save on a/c.

You can increase insulation in walls and roof, decrease heat loss via windows, doors and leaks. You can implement passive measures, like earth sheltering, good plantings to reduce wind, deciduous trees to provide shade in summer, but allow sun in winter, roof overhangs that provide shade in summer, but let the lower-angled sun in during winter. You can site a building to maximize solar potential, and to use prevailing winds for cooling. The stack effect can provide significant natural cooling. In dry climates, a swamp cooler can be quite effective. And, you can make buildings smarter-sized; a well-designed building doesn't need as much square footage to heat, cool, maintain, etc.

Local materials save transportation. Houses don't have to be made of plastic; I used pressed tin(steel, actually) for my kitchen backsplash; easy to clean, looks nice, easy install, easily recycled.

Your local Cooperative Extension office is probably a good resource.

http://www.greenbuilding.com/homeowners/green-home-improvement/additions-remodeling/green-kitchen-remodel
http://www.epa.gov/greenbuilding/pubs/faqs.htm
http://www.greenbuilding.com
http://www.nrdc.org/buildinggreen/
http://en.wikipedia.org/wiki/Green_building
http://publications.usa.gov/USAPubs.php?PubID=1320
http://www.usgbc.org/DisplayPage.aspx?CategoryID=19
http://www.usgbc.org/DisplayPage.aspx?CMSPageID=1718
posted by theora55 at 5:29 PM on November 27, 2011 [6 favorites]

Funny thing: I was recently talking with a neighbor about the home that he had dramatically renovated using "passive design." I've heard of passive heating, but here in Austin, that's not as much of an issue as cooling.

He explained that the word "passive" is sort of a brand name that represents two principles:
1. Designing for a specific outcome instead of "as efficient as possible, damn the torpedoes" and
2. Keeping the build price the same as a conventional build.

He says that with passive design, your upfront costs will be the same (or very close), but your recurring energy costs will be dramatically lower. He had his home chilled much colder than I ever have mine, using an AC system with 1/5 the cooling capacity. It's by downscaling the AC system and things like that, and investing the money in better windows, etc, that you break even upfront.

So you might want to research that.
posted by adamrice at 5:31 PM on November 27, 2011

Buildings have to be built according to building codes. The people who design and manufacture building components are concerned primarily about sales. New homes are built to be attractive to sell, not necessarily efficient to operate. Consumers haven't demanded really energy-efficient buildings, at least not if they'll cost more.

I think this response is really key here. Developers and construction contractors are interested principally in what sells and what is up to code. To the extent that customers don't demand more efficient housing, such housing will not be built. Then you also have to contend with the question of whether a given efficiency technology comports with the relevant local code. Remember that a contractor/developer/architect is not going to use some energy-efficient technology that violates the law. Well, at least the competent ones with whom you will want to deal will not use technology that has not been vetted/does not comply with laws and regulations.

So, to review: (1) consumer apathy and (2) bureaucratic inertia are the two main reasons that energy efficient housing has not been as successful as its proponents would want.
posted by dfriedman at 5:45 PM on November 27, 2011

I would subscribe to Fine Homebuilding magazine; they write about these topics almost every issue, and even smaller DIY articles are fully informed by the energy conservation approach.

You will find that there are quite a few certifications out there for professionals, depending on specialty, and still a lot of diversity of approach.

The three major standards of green building to be aware of are:
* Energy Star (call this the lowest common denominator approach)
* LEED (from the US Green Building Council, a trade group standard that is stricter and has different certification levels)
* Passivhaus/Passive House (call this the Extreme edition; the goal more or less is a house in a northern climate that uses the energy of a hair dryer to warm itself)

Help me to understand the ADDED costs of achieving higher levels of energy efficiency, going beyond the existing Building Code energy requirements, (e.g. using German triple-pane windows instead of domestic double-pane, how much more?) and how do you figure the spread out to the building's future use?

Hoo boy. This is literally the million-dollar question. There are software tools that you can get from various sources that will give you some idea of the ROI on a given upgrade, but they require a lot of experience to use properly. There are things that are DIY-appropriate, rehab-appropriate, and new-construction-only appropriate, and again that takes experience to master. In many cases you'll want a green-certified architect on board with you. The basic lesson is pretty much spending more up front to reduce heating and cooling consumption and/or costs. For some the costs aren't as important as the consumption, viz. spending $100,000 more (which can easily happen) to save $1000/yr on heating and cooling. Others need the investment to pay off more directly. This is not an area where you'll just get simple answers; you'll probably get three wildly varying answers even from trained pros.
posted by dhartung at 6:27 PM on November 27, 2011

My local extension office has a lot of links and publications on energy conservation, which you might find interesting and useful. Much is based on the fact that we're in a pretty extreme climate (Alaska) and heating is a big problem (and heating oil is really expensive).
posted by leahwrenn at 6:59 PM on November 27, 2011

Thirding LEED as a decent resource that combines mainstream and 'green' choices.

Most times the simplest answer is to do without X, Y, or Z. Once you get past that choice it really becomes the optimization game mentioned in the OP's post.

Want to reduce impact (and therefor cost)? Forego the lawn entirely and go with rock garden. Not OK with that? Go with some local/low water/care plants. Still need the green lawn? How about we just go with a rain barrel to supplement your watering scheme...

That same thing pretty much applies to any choice you're wanting to make in life, this one is just complex in that you're trying to consider the entire lifecycle of a choice.

Consider looking into permaculture as a choice in design as well. May be a bit hippy, nutty, crunchy for your question but it really does hit on some of the things mentioned above in an intelligent, thoughtful manner.
posted by RolandOfEld at 8:39 AM on November 28, 2011

Not finding a great link for it, but the concept that underlies the argument against "payback time will never justify the up-front costs" is what Amory Lovins calls "Tunneling through the cost barrier"; this is the same philosophy that the Passivhaus model relies on: by increasing your thermal insulation and reducing air infiltration, and improving overall U-value of your envelope, at a certain point you can begin to eliminate whole systems from your project, eliminating huge chunks of up-front cost, and actually lowering your first costs, as well as significantly reducing operating expenses.
posted by misterbrandt at 10:42 AM on November 28, 2011

Response by poster: Great answers, thanks. misterbrandt pls send link if located
posted by ebesan at 2:42 PM on November 28, 2011

ebesan, here you go (scroll down a bit).

Also, take a look at slides 11 and 13 of the PDF [warning: direct PDF download] at the link in my previous comment.
posted by misterbrandt at 3:04 PM on November 28, 2011