[jasont]

This is an interesting discussion and something I personally haven't thought too much into. However a number of things come to mind.

The first thing that hits me is your projected time frame of holding the property BF. I am not too sure about Europe but out here in Australia, banks won't force you to get property revalued unless you are changing the mortgage in some way.

If you are planning on holding for a number of years to come (as most property investors tend to do unless they are doing renovations and flipping them), then a good hedge in one way is to simply avoid re-financing as much as possible. Of course this is only worthwhile if a) you plan to hold for say at least 10 years and b) you can afford to continue to pay the repayments quite comfortably.

There are the smaller details of locking in fixed rates vs variable ones due to the current rate situation but I think that depends on a property value vs repayments cases by case basis on each property.

This does appear to be a typical buy and hold strategy where not realizing paper losses doesn't necessarily mean you haven't lost. However it is the same in any type of trading. If you trade intra day, you don't have to close your trade after 2 minutes because it is in the red when you are looking to hold the position for a couple of hours.

Shorter term losses can be held onto and unrealized if your view is to hold for much longer. The same as buy and hold investors if their current outlook on stocks is 10 years plus. Even if they bought at the top of this market back in 2007, it may be premature to close out positions now if they wanted to hold into 2020 on most stocks.

So really my point based on what happens out here in Australia, there may not be a need to hedge against one's property portfolio beyond trying to increase rent, if banks don't force you to re-value your property and you plan on holding long term.