[Cob] GERMAN house rant on passive

[howard at earthandstraw.com]

>well the thing is I don't know of many homes being built here in the
>USA that have no heat source other than the walls, do you?

I expect there are a number of them.  The house we built for Albert Bates' mother in 1980 has seldom ever required any back up heat and the Lovins home at Rocky Mountain Institute also, I believe, doesn't require backup.  With enough thermal mass, insolation and insulation a moderate temperature in the comfort range can be maintained.  I stayed in the Bates' house for a couple days not long after it was built, and before it was moved into, no drapes on any of the glass etc., a rare blizzard was in progress, no sun for three days, outdoor temperatures in the teens and we could get up in the middle of the night barefoot on the ceramic tiled floor slab and be comfortable.  While the thermometer read that it was 65 it felt warmer because of being surrounded with all that still luke warm and radiating mass.  Yes, I was amazed and delighted.  We built another one soon after for a retired Air Force colonel who was impressed after visiting the house several times in challenging conditions, but it was lost when the GM Saturn Plant was built.  The design included an attached greenhouse, a vented trombe wall, clerestories and much direct gain, real solar smorgasbord. I had 8" solid masonry for the exterior walls with 3" of foam and brick veneer outside of that, a "cavity wall."  The Lovins house is also a masonry cavity wall filled with foam.  So, it can be done. I hope to see a performance report on a cob passive solar design in this region.  We expect to be building one this year for a client near Nashville, TN.  We'll see.

My experience left me wondering why people were not insisting on them making it a convention despite having cheap energy.  Of course that is changing.


Howard Switzer, Architect
668 Hurricane Creek Road
Linden, TN 37096
931-589-6513
www.earthandstraw.com