Excellent thread!
Our situation which may or may not be relevant to you:
Our 'retirement home' will be paid off, but unless we're renting part of it out, we won't include it in our net worth calculations. It will be in a much cheaper area than the places we live and work in now (major cities like Beijing, Hong Kong, maybe Manchester/London UK later). We currently own one fully paid for house (in the US we'd call it an apartment/condo) in inland Sicily, a region where land/house prices are quite low, but where there's a large holiday market for part of the year. So we rent the house out to holidaymakers now, and make about a 10% return, most of which is reinvested in improvements (so isn't a classic return I suppose).
We plan to buy up to a half-dozen little properties across Sicily, and eventually consolidate them once we've finalized where we want to live on the island. Then we'll manage several properties - or a block of flats/B&B - from our home base. All these properties will be bought with cash; this is how Italians have traditionally bought homes (aside from the coast and major cities), and a mortgage isn't an option unless we're willing to take a low-paying job there. We;re also looking at the UK as an option to buy leveraged properties, particularly in the commercial sector in my husband's hometown.