Cob home size

[Shannon C. Dealy]

Cob houses can be built as large as you like.  If you want to build it
several stories tall, then you would need to be more careful in your
design and it would be necessary to make the walls on the lower floors
much thicker in order to support the weight of the walls above them and
retain stability. In addition, for multi-level cob buildings, all cob
walls on the upper floors would have to be a continuation of a wall from a
lower floor.  It is also a good idea as a general design rule to include
cob buttresses built into the wall and use continuous curved walls rather
than straight or free standing walls, particularly as the walls get
taller.  For a single or two level structure of any arbitrary size there
should be no real design problems, though it is best to make the walls as
stable and self supporting as possible (particularly if you are building
in an earthquake zone). It is not so much that the cob walls are unstable
(given their thickness, they should be much more stable than conventional
walls), but rather that given their mass, they are much more dangerous
should they ever collapse due to a natural disaster (flooding,
earthquake, etc).

Shannon Dealy
dealy at deatech.com