Cohousing-L Mailing List: Re: Manufactured Housing-Foam Core

[Eric D. Hart (harte]

Foam core building systems seem to be the latest rage in 'green' building 
materials these days.  In my opinion these building systems are the farthest 
from 'green' as you can get.  If the foam in these panels is expanded 
polystyrene (I do not know of any which are not) then regardless of 
whether or not it is made without CFCs, etc. it is still an ecological 
disaster.  All petroleum products (regardless if they become inert or 
not) require massive amounts of energy to produce and create massive 
amounts of pollution at the same time.  The polymer industry is one of 
the most polluting there is and chlorine is used in the manufacture of 
polymers of many types (forming many noxious pollutants, including 
dioxin).  There are many much more environmentally sound insulation 
materials than petroleum based foam core panel. In addition these foam 
panels get their strength for structural purposes from oriented strand 
board (OSB).  OSB is small strands of wood glued together with various 
resins.  Those resins can be made so they do not off gas, but as far as I 
know there aren't any that are benign both in the manufacturing process 
and after they are on your house.  There is one of these plants in 
Northern Minnesota where workers are getting very sick being exposed to 
the chemicals that are used in the resins.  So if you want to avoid all 
these things don't even think about foam core panels.  I also have 
questions about how good it is that the panels are air tight.  That water 
has to go somewhere and it might stick around in the wall and rot away 
whatever wood is there.
        I'm organizing the Community Eco-design Network here in 
Minneapolis and we are trying to figure out what the most 'green' 
building techniques and materials are to use in structures.  That's why 
you may have noticed that this topic is a hot button for me.  There are 
many tradeoffs in building in the most environmentally sensitive manner 
possible but foam core panels have so many things going against them that 
I won't even consider them.  The superinsulated building system we are 
looking at involves using post and beam construction with strawbale 
infill (legal under existing codes).  This is a fairly straight forward 
and easy to build method that shouldn't present any code compliance 
problems.  
Rick Peterson, an architect, has come up with a 2,200 ft2 common 
house with 3-4 small housing units which uses this building technique.  
He has also drawn up some small houses which we are included in a plan 
book that will be issued in the near future.  

Eric Hart
Community Eco-design Network
Minneapolis, MN