Climate-safe home design - alternative building is ready to go mainstream.

January 14, 2007 2:13 PM

Passivhaus/Passive house design that saves mucho energy, does not require air conditioning, does not require heating even when outdoors it's 10 below! Since, for example, more than 30% of energy consumed in the UK is for homes and 82 per cent of that is space and water heating, [Monbiot, "Heat,"chapter 5, "Our Leaky Homes,"] changing our standards of home design is important. Diagram shows that basic solar design concepts are well understood and technically easy to implement in new construction. [If only my house could be turned 45 degrees!] Possibly through ignorance, and partly through the desire to cut corners instead of doing things right, we do not make these wise concepts a priority. There are lots of cool alternative building techniques, many of which are traditional and being revived. This leading design standard saves 90% of energy used in the home. Here in Canada it's called the net zero energy home.
posted by Listener (16 comments total)

Great post, Listener.

Can anyone attest to the comfort level of passive cooling? In my experience, Germans (and Europeans in general) have a much higher tolerance for heat and humidity than Americans do.
posted by bonecrusher at 2:26 PM on January 14, 2007

The Bergen, Norway Architecture School had a very good program in this in 2002. I don't know if they are still doing their program about small passively heated and cooled houses, but it was a highly innovative program for a country where everyone has triple-paned windows.
posted by parmanparman at 2:30 PM on January 14, 2007

It's important not to confuse passive solar heating / LEED / Earthcraft /etc. with the Passivhaus standard. Passivehaus is developed at an extremely stringent level that is more energy-stingy than most energy-efficient housing here in the U.S. My wife and I will begin building our own LEED-compliant home in the next few months, and while that's a pretty serious standard, that's nowhere as near as hardcore as Passivhaus.
posted by waldo at 2:44 PM on January 14, 2007

I wonder if I can incorporate this into my next place - which is going to be a yurt hell or high water.
posted by evilelvis at 2:50 PM on January 14, 2007

See also: Earthships.
posted by Rubber Soul at 3:14 PM on January 14, 2007

I heard washington DC just made it law for all commercial buildings of x size be leed certified. Yay!

Most people who care about energy issues attack cars and transit as the biggiest contributor to global warming, when in fact it is our buildings that contribute the most greenhouse gasses.

it costs on average oround %2 percent extra for a new building to be leed certified (at the silver level i believe), and building owners make back this cost in terms of energy savings within 5 years.

If our country could get our collective heads out of our collective asses, we'd realize how profitable sustainability is, even in the short term.

(yes, leed pales in comparison to those clever folk across the altlantic, but hey. what can you expect from a bunch of shortsighted, iraq surging, .. I'll stop here...)
posted by localhuman at 6:10 PM on January 14, 2007

In my experience, Germans (and Europeans in general) have a much higher tolerance for heat and humidity than Americans do.

An interesting anecdote in regards to cold tolerance; I've heard both Europeans and North Americans complain that the coldest they've been inside is in an Australian house in winter. It seems you all have crazy central heating up there in the northern hemisphere, creating glowing warm interiors, while we just shrug, say "Hey it's not like it ever snows here" and pull on another jumper.

I'm interested to learn about passive designs that are appropriate for humid, tropical conditions. We try our best, with louvered windows to catch the breeze, raised houses etc. but when it's calm and humid, it feels there's no place to hide, and we might as well close the windows and turn on the air conditioner. But, of course, a billion people living in the tropics survive quite happily without them...
posted by Jimbob at 6:15 PM on January 14, 2007

Actually Jimbob, in New Zealand in winter is where you get a damned cold and damp house. Much worse than a southern Australian one. They think they're tough, the kiwis, but it genuinely kills a significant number of the elderly every year.
posted by wilful at 9:36 PM on January 14, 2007

Oh one other thing - a lot of passive heating/cooling design standards indirectly encourage the use of concrete and fired brick, and discourage earth wall techniques and timber floors (or make it hard for them to meet the grade). This means that the embodied energy of the structure is much higher than it could be and it would take many years of heating and cooling to reach the same carbon emissions.
posted by wilful at 9:39 PM on January 14, 2007

Not to bust on the building industry here, and congrats to you, Waldo, for building a LEED cert house, but a lot of LEED, IMHO, is a lot of crap - the Kimberly process of construction. Platnium and gold are good, but silver and bronze are weak; regional variations are hardly accounted for; everyone gets WAYY too much credit for using low-emission paint and carpet, without adding real energy or water savings to their bldgs. I actually had a plumber tell me how he intended remove a water reducer after inspection, very common, it would seem. And drywall counts as a low-impact ingredient because they use recycled paper on it... like the tons and tons of gypsum ripped from the earth is all accounted and paid for, because they used a tiny bit of recycled paper! Makes me crazy.
posted by DenOfSizer at 5:57 AM on January 15, 2007 [1 favorite]

I'm interested to learn about passive designs that are appropriate for humid, tropical conditions.

Jimbob, you're probably aware of Glenn Murcutt. Noted for his light footprints, passive heating as well as passive cooling strategies (pdf) and incredibly beautiful work.
posted by xod at 8:34 AM on January 15, 2007

Right now my brother-in-law is in Thailand learning cobb construction. I think they're building a school.
I'll have to forward him a link to this post.
Thanks, Listener.
posted by bstreep at 9:15 AM on January 15, 2007

It's important not to confuse passive solar heating / LEED / Earthcraft /etc. with the Passivhaus standard.

Yes, I didn't mean to confuse them, but to introduce a few people, perchance, to cob and strawbale and the alternative building history of recent decades. The passivhaus is a huge bump up from basic passive solar plus thermal mass, and a key element seems to be ensuring there are not thermal bridges that conduct heat between interior and exterior.

Can anyone attest to the comfort level of passive cooling?

The passive cooling example given in one link was 35C outdoors and 25C indoors. That's about 96F down to 80F. Still hot, but bearable with a fan in the hottest part of the day. I put up with that here in the summer. I have a shade rolled down over the window and it makes a world of difference, stopping the greenhouse effect in my office. I guess a bit of heat tolerance can be built up, if there's a difference between Europeans and North Americans.
posted by Listener at 9:44 AM on January 15, 2007

I taught violin to a young girl for a few years and got to know her parents (University art profs and certain former hippies, both of them) pretty well. I was always curious about the house's unusual construction: it was angled differently than others in the neighborhood, with a main room clad along one side with picture windows. The mother told me it was built to be "passively heated and cooled" and that they had help from another university prof when building it years before.

They never did have the furnace or a/c on all that much, from what I could tell. Consequently, though in other children's houses sudden weather changes were hell on the violins (forcing me to stop and retune every five minutes), I never had many problems there.

Got me interested, it did. I think I shall have to build something like that when my ship comes in. My contractor uncle keeps insisting he'll build my house eventually, but I have to smirk: not if you're building me a generic suburban timber-frame!
posted by adoarns at 11:04 AM on January 15, 2007

My dept has some connections with a UK green architect firm, ZEDfactory. ZED stading for Zero Emission Dwelling. They developed a project called BedZED a few years ago in London and have been working on a rural variant (RuralZED) in recent years. The idea is that they will sell 'flat packs' for the house which should be available at pretty reasonable prices (by UK standards especially) - about £60K supposedly , these will have high levels of solar gain, energy efficiency and with a passive heating /cooling system. The price of the kit includes a training course in putting the thing together. They've adapted some of the technology for a development which has recently opened near us and which has had the Guardian asking if its the greenest building in the UK. (I'll provide a link to the Guardian article but the site seems to be down at the moment.) It's a larger scale variation built to high insulation standards and with a built-in biomass burner for heat, wind turbines for electricity and solar thermal for water heating. There's a picture on my first link.
posted by biffa at 10:02 AM on January 25, 2007

That Guardian link is here.
posted by biffa at 10:30 AM on January 25, 2007