Re: [GBlist] re: truly sustainable

["Brenda Norman" <bnorman@ceiarchitecture.com>]

Its never simple...You've left off the energy use of the building while its
in operation, which far outweighs the embodied energy of the materials to
build it (as well, you've used old growth wood which will have a whole
different ecosystem that can't be easily replaced).  If the
materials/systems you incorporate reduce the energy consumption or use
renewable energy sources such as sunlight you will be more 'sustainable'
than by simply using materials that last a long time and/or have low
embodied energy - not to say that these two goals are mutually exclusive...
and this is just the start, there are questions of connections to the
community, density, and more...

----- Original Message -----
From: "David Wagner" <dwagner@sa.kevric.com>
To: <greenbuilding@crest.org>
Sent: Thursday, September 27, 2001 12:57 PM
Subject: RE: [GBlist] re: truly sustainable


> Well, I agree with the durability and reworkability of a structure
> being critical to the 'greenness' of a building material.  If you have
> to replace your home every twenty years, the materials must be better
> than 1/10 the impact of the materials used to build a structure to
> last 200.  Let me see if I can break this down for a timber and stone
> building.  I won't get the numbers right, but perhaps others can
> correct these assumptions.
>
> Let's say killing one tree 200 years old will give me enough timber
> for 1,000 square feet or 10,000 cubic feet of a generic timber-frame
> and stone structure which will last 200 years.  (Again, these numbers
> are guesses, subject to correction by someone who knows more than I.)
> If an ecosystem can spare it, I could have the tree chopped down, so
> long as I replace it.  To guarantee its replacement, I will have to
> find, purchase, and place a conservation easement for 200 years on
> 1/10 acre of land in need of a tree, contiguous with an existing
> protected forest ecosystem, enough space to plant 2 trees, one of
> which is likely to live to 200 years.  This tree was sinking
> atmospheric CO2, producing oxygen, and filtering water until I cut it
> down, and the seedlings won't be up to its capacity for quite a while.
> So, I owe everyone some CO2 reduction and some oxygen to breathe, and
> I owe the community near the tree a bit of fresh water.
>
> Let's say I also choose fieldstone.  I will also need to acquire the
> mineral rights for a parcel large enough to heave up the amount of
> stone I need, and protect it with some legal provision to prevent
> mining for long enough to do so.  If the land beneath those trees is
> not enough, I may need to add some.    That covers the costs of
> acquiring these materials.  (I think; please add comments.)
>
> There are also some other benefits.  Besides gaining the dead tree, I
> have protected at least 1/10 of an acre of forest ecosystem.  Since I
> try not to be greedy, I'll donate it to a nonprofit organization to
> preserve as public land (with the easements in place and mineral
> rights secured against use by anyone for a very long time, of course).
>
> Now there are similar things to do to completely account for the
> processing and transport of these materials.  I am likely to find I
> cannot possibly afford transporting fieldstone from under those trees
> and compensating for the environmental impact of this folly.  I am
> also personally of the opinion right now we need a few centuries of
> forest restoration before consuming any more timber, but just because
> this is my opinion does not mean we cannot reasonably consider timber
> costs when forests are restored and can be harvested sustainably.
> But, back to this analysis.
>
> There are limestone quarries in my area.  What are the costs of
> removing, say, one ton of limestone?  How must I compensate?  When I
> finish the whole building design, is the total cost to me something
> six billion other people could do limited by the resources of this
> planet?  If not, I need to look very hard at my design and my choices
> of how and even where to live.
>
> As for labor, I agree it has very high value, and do not plan to
> translate it immediately into local currency, but to account it as
> hours of a particular skill, for example, 1 hr time cost to the
> sawyer.  What the sawyer will accept as fair trade in exchange for
> this hour is negotiable, but I think $20(US2000) is a reasonable
> default value for the time of a US citizen.  (This is double the
> $10/hr living wage advocated, since my own personal opinion is we
> should be compelled to work for others at most 20 hours in a week.
> Again, if there is enough interest and information to get an analysis
> system like this online, people will be able to change the default
> assumptions when they use it.)
>
> Does anyone else think this is a useful exercise?  Could it be?
>
> -David
>
>
> In response to what Chris Koehn wrote:
> > Here, we have lots of wood, and in
> > my immediate
> > area lots of field and quarry stone. While our area wasn't
> > settled until the
> > early 1800's, the examples of structures which have endured
> > the past 150-200
> > years are almost all timber and stone. One can, of course,
> > argue that those
> > are the materials the settlers were used to working with and
> > really the only
> > substantial materials available then. But we can also look to
> > the places
> > these settlers came from, which often had similar climates
> > (and, in the case
> > of much of Europe, a depleted wood resource, due to
> > over-use..). Wood and
> > stone were the materials of choice there, and indeed when I travel
> to
> > northern Europe I see that these are the buildings which
> > endure. Certainly
> > other organic materials were available- my supposition is
> > that if they were
> > used they have not survived the test of time in nearly the
> > numbers that
> > timber and masonry structures have.
> >
>
>
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>


______________________________________________________________________
This greenbuilding dialogue is sponsored by REPP/CREST, creator of
Solstice http://www.crest.org, and BuildingGreen, Inc., publisher of
Environmental Building News and GreenSpec http://www.BuildingGreen.com
______________________________________________________________________