On 28/11/2010 08:25, harry wrote:

My previous house had stone walls
four feet thick.

A castle? A converted lighthouse? A jail?

Farmhouse. Late Tudor. Welsh hills. Elevation 1000' Raised cruck
construction. Footings nil. Depth of "foundation" abour six inches.
Walls thick enough to incorporate spiral staircases.

I happen to know someone who lives in an old (not that old) Welsh
farmhouse with a spiral stair built into the gable end. Gable ends apart
the walls are the typical thickness for rubble filled stone walls - 2
feet. Walls plus chimney breasts can also be up to 4 feet thick (I am am
sitting right next to one as I type) but unless wall thickness is
required for stairs or fireplaces there was no benefit from building
houses with walls more than two feet thick except for defence or support
for a massive structure above.