Its 0.22 W/m.K for existing building Thanks for the link
Found very useful site for calculating the thickness of insulation required for a floor's U-value to comply with current Building Regulations.
Http://www.idhee.org.uk/UvalueCalc.php
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im trying to work out what the minimum thickness of kingspan I can use on an uninsulated concrete floor dimensions 3m by 4m to meet 2014 UK regs is :?: