We recently had the 9 inch solid walls of our house insulated with 90mm
EPS board and finished with the light weight render. We never really had
any overheating problems prior to this but everyone has noticed the
house is much cooler! Whether 9 inch solid walls are classed as 'a lot'
of thermal mass I don't know but we certainly notice it is cooler than
other houses that have the insulation applied internally or are of a
different construction.



That is a fair bit of mass ... I had 18" stone walls in previous place
never overheated

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UK SelfBuild: http://uk.groups.yahoo.com/group/UK_Selfbuild/