Legal advice re Separation / subdivision of house please?

[OldLace]

Separated from H for 3 years.
Still married but living apart and all finances separate.
He lives in the old marital home. He has paid both halves of the joint mortgage (its low) but no maintanance for kids (would have been more).
I now want to return, he agrees but we will not cohabit.
If he moves out, he says he wont be able to afford maintenance (2 kids with SEN/ASD, I am their carer, and disabled myself)
The house lends itself to being subdivided as there is a basement which could be easily converted and has a separate entrance.
There is a joint mortgage. Neither can afford to buy the other out.
If we sell there is no realistic chance of me affording anywhere else.
The mortgage is interest only and has 10 years to run. There is almost no equity but it would give me stability for 10 years and be cheaper than private rent.
He has agreed that a Separation Agreement would put the house 'in my name' (though the deeds cant be changed due to the mortgage and neither of us can come 'off' the mortgage with our providor).

Can it be done legally? What rights would he have living in the basement? He wouldnt pay rent but would then pay maintenance.

I appreciate I need to see an actual lawyer but this is difficult logistically and I need to start to make some decisions (I will see one, but would appreciate any advice that Scotsnet can offer meantime)

Hope this makes sense?

I think it's too complicated to be able to offer decent advice. For example the mortgage provider might be unhappy for him to be effectively liable to pay for a house he has no legal interest in.

If the mortgage is interest only, what provision have you made to repay the balance when it ends in 10 years? Do you have a endowment policy? who are the owners/lives assured of that?

Would you get permission to effectively create an additional separate dwelling or would you leave it as an unofficial thing?

I'm not expecting you to answer above btw, as I don't know the implications, just posing some things that you'd need to consider.

There might very well be some straightforward way to do this.

thanks for replying WaxOnFeckOff

when the mortgage was taken out we were both working.
I became disabled and had two disabled kids who need a Carer.
Hence moving to Int only. No provision for 10 years except selling.
H has life insurance, I dont.

I take your points.

Oldlace, really sorry to hear the position you are in, I really hope something works out, would you be able to be housed/get housing benefit if you were to sell now and go your own financial ways? Again, I don't mean you to answer, just another option as to be honest that's really what it's going to come to in 10 years anyway unless you are expecting a decent sum of money to appear before then.

It is, yes.
Just hoping to give stability to the kids until then.
It would also mean that the other parent was 'on site' in times of emergency which can be useful with SN kids.
(he is a dickhead, tbh, but I can safely leave one dc with him whilst i take the other to hosp, which was the situation twice last week when i had to drag the other dc along, so, practicalities)