Does anyone know how much extra heat-insulation value the addition of
shiplap cladding is likely to make to a house? I'm not thinking of
adding it for insulation value, rather to cover up the hideous exterior
currently on show. But it would be interesting to know if there will by
an increase in insulation as a by-product. If there isn't much, then I
might consider laying more insulation in the loft.

Eddy.