I don’t know if the title is clear enough and if the subject was already discussed or not.
I own 2 houses (one since 1 year, witch is my residence, the other one since 10 years). I wonder if I could use the unrealized capital gain (or latent added value) to buy some other property or if I still need more income (my income is not high enough to support an other property but if I rent it, does it count?).
Any input is welcome 
Normally you do this by mortgaging the property and using the funds to buy property.
Ok, so let’s say that 1st house value as increased by 200’000 and value of the 2nd by 100’000.
I could increase both mortgages to get these 300’000 to make a 3rd mortgage and buy a flat. Right?
But then, would it be possible that the loans are high enough to cover the 3rd mortgage (I mean with the 5%+1%+1% rule of the banks)?
If your bank, or a different lender, is okay with it your plan should work.
Since so much depends on your personal financial circumstances and the banks willingness to help you with it, you should schedule a meeting with your bank.
Would you have a plan how to cope with that leverage if real estate prices ever went down? (the unthinkable, I know)
Sell something 