'No he will not leave. This is his house, as he states, so he will not leave.'
Go to your local CAB and ask if it really is his house and if he can be removed. He may have led you to believe that the house is his, but remember where your information is coming from.
Your DH may well fight you every step of the way wrt selling the house, but you have as good a chance of winning as he does, maybe even better. Even if it must be sold, you could argue for time to allow the economy to pick up again.
They don't get their own way when you disengage. They lose. What they see as winning is you living your life as a satellite of them. They don't care about the quality of the exchanges between you as long as there is some sort of dance going on. They don't care if they live with you under the same roof and the two of you never speak. Every time you pass, and are conscious of each other's existence they score a victory. The only way to win is to live in a way that tells them that you are indifferent to their existence.
My ex is turning into a serial litigant. Why? Because by bringing constant motions against me on ridiculous grounds he thinks he has me paying attention to him, living my life afraid of what he might do if I do my own thing, a planet orbiting his sun. We have been separated for almost four years now and he is still desperate to keep me in his orbit because he can only live in relation to someone else, and in that relationship he has to have the role of dominator. Engaging and fighting is just fuel to his fire. We do not speak much at all. Communication is the minimum required to convey basic information about the DCs' weekend schedule on weekends when he has them.
I am in the process of selling my own 4 bed house to retire the marital debt after divorce, and though it was difficult for the DCs to learn what had to happen, they have settled into the routine of keeping everything tidy so the house can be shown, and have accepted that I will do my level best to find a nice alternative for us when someone buys it. It was very hard to tell the children that their familiar home must be sold, and it took me months to work up to it. They took it well, considering, and fingers crossed, all will work out and I will find somewhere reasonably decent to rent and then we can all get on with our lives. We will still be a family no matter where we live. The cat will come with us to the new place. We will still have a somewhat burned dinner together every day, spend a while chatting together at bedtime, they will still go to the same school and have the same friends, and their books and things that are now packed away will all be taken out once again when we are settled. They have taken comfort in my assurances to them about their lives. Sometimes I think the children have their heads screwed on better than I do.
It is very hard to let go of the family house, because it represents the children's lives and the hopes you have for their happiness, the feelings of failure and guilt you feel for 'quitting', not to mention your own hopes and everything you have built your life around. I went to see 'Up' and nearly had to leave the cinema because the story was so poignant and immediate for me.
Quattrocento, the point of gaslighting is that it is done without leaving any hint of evidence behind it. The effect is felt but there is no way you can prove it was done. Your last post generated more heat than light.
FF ...'lose his family. If he is a narcissistic personality then surely he won't care anyway?'
He will care because conflict over the children gives him the chance to engage with you. If you divorce, get a rock solid visitation agreement that covers every day of the year, with times of exchange stated. Leave no stone unturned. He won't care about the children pr about being a father per se. He will be concerned with issues of entitlement and the possibilities generated by the need for communication about the children for bullying you.
'My DH has already informed me that he would not be a weekend father anyway so he will not have lost anything.'
My exH informed me he would have just as much contact with the children as he had when we were together. Well, DD1 no longer speaks to him, hasn't since she was about 15, and DS will have nothing more to do with him once he turns 18; he only goes every second weekend now because he has counted the weekends that are left until freedom and realises he can put up with it until the magic 18th b-day arrives. The other DCs are not far behind. He has alienated every single one of them. Your DH will want to be a weekend father if he thinks that would make him a thorn in your flesh or if he thought he was somehow winning at some aspect of the anti F game he plays.
'In fact, because all he cares about is himself, he will actually have gained by not having to actually look after his own DCs at weekends. He will be free to do whatever he wants.'
It is actually a victory for you if he withdraws completely from the children's lives, and definitely a victory for the children. All he wants is to be antagonistic. When he realises how much he needs the emotional sustenance that he gets from dominating you he may change his tune and grasp whatever opportunity he can lay his hands on to exert that domination. If he thinks he can be more antagonistic by insisting on Father's Rights he will fight you for access. Plus, he may want access to the children because children represent little orbiting planets to someone like him. He has this access now. He may find that he desperately needs it when it is taken away from him. If he is a narcissist, he will use the children the same way he is using you if he has that weekend access to them.
For my DD1, a tough cookie, the result of exH's narcissistic behaviour was that she refused to be bullied, stood up to him, and made it clear he would have to strike her to get her to jump when he commanded, which was his thing with the children -- he loved to see them afraid of him. She also made it clear that if he laid a finger on her she would not hesitate to go nuclear and call the police, and I backed her up. He had to admit defeat. He knows he has played his trump card and lost with DS too but insists on exacting his pound of flesh every second weekend. He misses the point spectacularly with the children. I consider myself and the children to be very unlucky that exH decided in his lawyerly way to insist on his rights wrt the children. Consider yourself and your DCs lucky if he decides to ride off into the sunset. Involvement with a father like this brings only pain.