Re: Design process & energy/heating/design issues
From: HeyHoskin (
Date: Tue, 13 Dec 94 21:04 CST
 Rob mentioned that he would like to see a list of some of the ecologically
sound/energy efficient technologies and practices currently being employed or
planned on in CoHousing communities.  I am with a group called Broward
Commons, we are located in Broward County, FL (Ft. Lauderdale) and as such
many of the ideas we plan to implement are oriented to a tropical climate.
 That being said here is our wish list.

*  Proper building orientation to sun, wind, local topography, and local
 vegitation.  This not only helps create a buiding which requires less
 energy  it also helps it  be integrated into the site instead of just put
 on the site.

*  Solar Energy (lots of sun down here!)

  Solar Domestic Hot Water- it is my feeling that nearly every   household
will utilize solar hot water heaters.  This is the solar 
  energy technology that pays for itself the soonest- in fact for a 
  family of four (or more) it may be the least cost option over the 
  long run.

  Photovoltaics- depending on cost (of course), units will be built   PV
ready.  That is to say that the electrical system will be   installed in such
a way as to easily facilitate the addition of a   PV system.  In addition,
there would be a structural component  that could either be converted to or
could ease the construction  of a battery room.  (My home will be completely
off the grid, thanks to  the dawn of efficient propane/natural gas central AC

*  Insulation

  Our primary energy load in S. FL is air conditioning.  As such   our
buildings need to incorporate good insulation and/or large  thermal mass.
 Thermal mass normally comes in the form of  rock or concrete.  It is my
impression that thick rock or concrete walls are  expensive and may be
prohobitively so.  These walls do offer the  advantage of being very strong
however, a real concern to us in  hurricane country.  We need to innvestigate
this more- any input  would be appreciated.  We have come across two
techniques for high  R-value walls.  The first is a product called Amhome.
 This is basically  a 5000psi concrete skeleton/frame filled with styrofoam
panels.   According to the manufacturer this system results in R-30 walls and
 R-50 roof (I'm sure this is measured at the center of the panel and not  at
the beam).  Personally the "foam home" is not my cup of tea but I'm  willing
to listen.  The other technique is straw bale construction (I was  very
excited to see the thread start the other day and I plan to  participate).
 As you may know, straw bale construction takes an  agricultural waste
product and turns it into a building material which  can provide R-55 walls
(roof?).  It is my understanding that while wall  material and construction
labor may be cheaper for straw bale,  the  added bureaucratic hoops
(engineering, over construction, etc.) bring  the price per square foot into
the range of traditional construction.  I  am personally interested in
combining the insulatory qualities of  straw bale walls with the thermal mass
of an internal cistern.  We'll  see.

*  Heat Gain Prevention

  In addition to insulation,  we will incorporate glazing and shading to
 prevent or minimize heat gain.  Shading will be accomplished with  overhangs
and vegitation.

*  Water

  Water is a precious commodity here, increased population and the  resultant
developement has severely endangered the unique  ecosystem that is the
Everglades. Rainwater roof catchment and  cisterns will be used to supply
water for toilets showers and irrigation.   Low use appliances will be
combined with grey water systems.  As  there is a need for irrigation water,
the grey water will most likely be  used for irrigation as opposed to
flushing (if we are allowed). 
  Xeriscape and ecosystem restoration will be exploited to the greatest
 extent possible.
*  Building Size

  We feel that the 3000 sq. ft. single family home is not exactly
 environmentally friendly.  As such we will strive to keep unit size as
 small as consensus will allow (<2000 ft. max.).

 I hope this is of some interest to you all.  I would of course welcome any
comments, questions or input.  I can steer people in the direction of some
great informatin if there is an interest.  As I said this is a wish list-
hopefully we can overcome the economic and regulatory obstacles we are sure
to encounter.

   Thrive on current solar income!   Chris Hoskin

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