Sounds like a cash out refinance would be the best way to tap into that equity. 

I only have good words about it, and cash flow is always over 100€/month per property.

That creates a really nice price / rent ratio which is favorable for investors looking for cash flow.

Condo's usually have high HOA dues which will eat into your cash flow.

My underwriting would have this large negative cash flow for 7 years.I would do a thorough underwriting but want to show using quick math the issue so I will use the 50% rule.  

I use buildium which is a good value and I think the integration with tenant turner alone saves triple the hours needed to be worth the cost.

Do you have cash reserves for capital expenses and improvements? 

My mum currently lives there, she is 80 and not very well, but you would also become a tenant in common and as such if you had the time you could profit 100% from the transaction, as I need cash urgently and am willing to heavily discount the asset.I am wondering if there is a market out there where someone wants to get a foothold in the London market by buying my part of the property.

Let's use that as an example. 20% down is $43,000 plus lender loan origination fees, closing costs etc is going to push you over $50,000 cash out of pocket.

I have done a handful of flips using cash, partnering with friends, and making it work.