The buildings sum insured should cover the cost to rebuild the property in the event of a total loss. It should not reflect the market value.
The rebuild cost should take into account the cost of architects and surveyors fees, the cost of clearing rubble and debris, as well as building materials and labour. Your buildings sum insured should reflect the rebuild costs of the structure of the main home, fixtures and fittings, outbuildings used for domestic purposes such as sheds, garages, greenhouses, boundary walls, swimming pools and patios. Further advice and help can be found along with a household rebuilding calculator on the Association of British Insurers website http://abi.bcis.co.uk/