not much, no need to lag, no fiber glass loft insulation, lot`s of cal so related problems with water pump`s , some areas boiler needs changing every approx 3 yr`s , materials much the same, easy to get, Building`s, stone or concrete / clay block, stone mainly surface then out through the wall to black poly, Newer concrete / clay and expensive stone, everything buried,
any more info please ask
Have a good one
Tim