Building should be insured for the amount of their rebuilding cost (not current market value), which can usually be found on the buyers' report or survey, obtained upon purchase of the property. However, please note that this figure will need to be revised in keeping with market inflation.
On the other hand, contents must be insured for the total current replacement cost of all items you would take with you if you were moving out. These items could include, but not limited to, carpets, curtains, furniture, electrical appliances, valuables, clothing and personal effects.