What to do with house-inheritance?

You've not said how old your children are, nor your ages. It is wise to revisit your will every few years to ensure it is still relevant and/or covers a material change of circumstances affecting any of you. You can change the house ownership from joint tenants to tenants in common if you wish. It's not fixed in stone. HOWEVER, it is best that you seek legal advice on this. It doesn't need to get complicated but you should understand the implications of decisions you make now. A solicitor will be able to guide you.

Do not rely on your DP leaving the house to your kids upon his death. He may very well meet someone else after you pass and forget all about his promises to you.

Surely who would care for your DC if you die would bea big consideration. Eg. If your sister will take them then you'd have to leave her money to care for DC.

People say they’ll do lots of things and then change their mind. I would want it all sorted out for my children in advance of my death. The chances are you won’t die while you still have your very generous death in service, so I would personally forget about that for the longer term. Sounds like you have a whole of life insurance worth £300,000 so they would get £150,000 each whenever you die - this may sound like a lot of money at the moment but if you die in 40 years time it might not be that much. I’m also assuming it’s not one where the premiums are reviewable – with these people often cancel them later as the premiums go up as they get older and become un affordable. I think if you did joint tenancy, you could regret it and and it could become the source of worry later on becauseI think there are risks attached to that. I can’t really see any reason why you would do joint tenancy in your circumstances. Most likely when your children get the inheritance they will use the money to buy a house or move to a bigger house perhaps if they have families of their own by then so it would be good for them to have some inheritance from a property, the value of which will have most likely followed the property market in terms of price inflation.

If OP dies, then her partner can make a will leaving it to the children. They should be made aware that If he remarries he should make a new will leaving some all to the children.

Let me tell you about my sister. She wasn’t married, had 2 children with her partner. She died very suddenly in her 40s, kids were 13 and 16 at the time. House owned as JT. He was nominated for her Death in Service (£70K). House was mortgaged up to the hilt.
DC received her pension until they left Uni as at that time they would have had to be married for her DP to receive it. A year after she died, he moved his new GF into the family home, married her months later and went on to have another child. They spent all his DIS very quickly - so much so that he didn’t even pay anything towards the DCs university costs. They’ve since moved house, it’s in joint names and he’s told his older DC that as they got some pension for a few years they won’t get the a share in the house when he dies, it will all go to his younger child.
Another woman has benefitted financially from my sister’s death, and that I can never forgive.

If you want to ringfence the property against care fees it would be better if he left a right to reside for you and his half to your kids.

This ☝️. It’s entirely your decision but in your circumstances I would still do TIC even if my partner had no children. You say he is leaving his half to you which is up to him, but I assume he has no other family he wants to benefit, like nieces and nephews? You’re in a different position as you have children and they would be my priority here, regardless of the DIS and life assurance. Say you die first and he remarries a new partner who has children, and he then dies … your half share goes ultimately to someone else’s children or even more distant relatives. I have a friend this happened to - her dad remarried someone who had no children, he then died and she inherited everything. She subsequently made a will to leave everything to her nieces on her death and my friend and her siblings got nothing. That might have been what he wanted but I doubt it and I definitely wouldn’t want that if I was in your circumstances. I wonder if you are feeling awkward about it because he’s said he’s leaving his share to you? He’s in a different situation to you having no children. If you do feel awkward or feel that it’s unfair that he’s you could tell him he doesn’t need to leave his share to you but you feel the right thing is for you to leave your share to your children, so you both do TIC and grant each other the right to continue living in the property until death (or earlier sale). I think you need to have a frank talk with each other and also see a solicitor which it sounds like you are going to do.

Fair, however your partner gets to stay in the house (if that’s what you want) until he cohabits, marries or dies, if that’s what you stipulate, and your kids get your share of the property after that AS LONG AS YOU GET A PROPERLY DRAFTED WILL.

What is confusing you?
This planning is my day job btw.

Ok, if you are TIC and the deceased spouse has left their share to beneficiaries other than the remaining spouse then the remaining spouse, should they need to go into care only owns half a house, the value of which is calculated as the value of half a house on the open market. The value of half a house on the open market is virtually nil, so is mostly disregarded when assessing their financial status re paying for the care home.

The Wills need to be properly written giving a right to reside to the remaining spouse with clauses setting out the rules regarding remarriage etc.
if the remaining spouse wishes to sell up, either the new property is bought as tenants in common with the beneficiaries or the proceeds of sale are split.

Tenants in common, it aids care home fees planning.

Re: Trusts.

I think clauses can be tweaked/added to include the ability to downsize. This kind of thing is then at the Trustees discretion. I assume you can make a proportional cash payment to the eventual beneficiaries at that point.
You can have a clause to dissolve the trust upon marriage/cohabiting.
It can be quite closely tailored as required.