Hi Lisa -
Intasure are prob the best I have found. To reduce the cost work out the re build cost if you can as this is alot lot lower than the actual price that you have paid for you apartment. I have had a quote for sum insured of 20k but I know that this is probably too much and before I go ahead I will work out the re build cost. Ask you agent or developer what the current re build cost is per sq m in your location and ensure you tell them it is for re build costs for insurance purposes. You will be surprised at how much you can bring down the insurance costs.
Intasure have said that:
There should be an element of community insurance in your service charge which cover communal area and the shell of the building - joint roof for instance
I am checking this out with my agent
Regards
Alison