When I was getting divorced, my aim was to keep the house. The alternative (which Ex wanted) was for us to sell the house. While fighting tooth and nail for what I wanted, I also researched and planned for the alternative.
The plan is to mediate with him and negotiate what you want - is that correct? But he is not engaging with mediation. How long are you prepared to wait for him to engage?
I know it was different in my case, as I was going through formal divorce settlement negotiation, but my solicitor referred us to mediation once court proceedings had begun, as this is what court would prefer. Mediator wrote a letter, separately, to each of us, requesting each made an assessment appointment. I made and attended mine, to find Ex had not even rung them!
This was about 3 weeks after the initial letters from mediator. She signed the case off immediately at my appointment. Ex would never have attended, even with follow up (and it would have cost him (as it did me) £100 - he was that strange beast, a miserly cocklodger)).