Which route is best?

AllyMac

Hmmmmm. You may not like this, but I'd be advising her something different altogether.
As her friend, I'd be reminding her that even the best relationships don't always last.
I'd be telling her NOT to make your debt her debt. Especially not your unsecured debt her secured debt!

I don't know your financial history, but I'd be saying to her - how come he's in £15K of debt, how do you know that you won't pay that off in your joint names and in 2 years time find out that you've got a larger mortgage AND a new large credit card debt on the go?

Not sure why you'd swap a 0% unsecured loan for a 2.5% (ish) secured one anyway - even without my concerns about the addition of passing your debt responsibility legally onto her.

I'm sorry that I sound cynical, but I also used a divorce and separation forum some years ago, and it was full of women who had taken on a man's debt because they had a better credit rating, and ended up stiffed.

If you were my boyfriend, I would let you move into my house without paying anything (or only the additional cost on bills, if I couldn't afford that) and let you use that great opportunity to pay off your debts quickly.

There's simply no way I'd step in and take on your debt (especially 0%)

So the order I would propose:
- pay off your debt
- house hunt
- legally protect her larger share
- pay off her ex