The notion that a high net worth individual can swagger into any city in the world and buy a property with few obstacles to overcome has taken a knock recently.

Singapore has hit foreigners with higher duty, while those buying top-end London homes will soon face a hefty annual charge. Similar measures are in place or under debate elsewhere as governments try to deflate market bubbles or ensure everyone – yes, even the wealthy – pays more tax to pay off budget deficits.

We have analysed eight world cities where HNWIs congregate. Using data from property consultancy Savills, based on the purchase of notional ￡2m pieds-à-terre, it is clear that buying processes vary widely but one common denominator exists: ownership is less straightforward and more costly now than in the recent past.