What percentage of Dwelling coverage should you have for a walls in policy?

[Atul Mathur]

I'm looking for some feedback/recommendations.   If you have an investment condo, what percentage of it's market value should you have for dwelling coverage in the event of a total loss?   For example, if you have a $300k condo, only the walls in are the landlord's responsibility so how much coverage would be appropriate in the event that the property is completly destroyed?  20% ($60k)?