I would be a little wary with the solicitor in the family, my experience tells me that you have to watch these sharks like a hawk. If it's no big deal for you then fair enough, but perhaps you can play the devious buggers at their own game and use it as a negotiation point. I am currently informally renting my property after thankfully selling my property just before the credit crunch, due to the fact that this property is actively on the market, i have negotiated a very favorable rental. I think you are in the same position given the terms they are offering. So my recommendation is to be upfront with them and show that you know the score and expect a reduction in rent. That's my two pennies worth anyway.