The biggest issue I see with this, is that your/ your partners children have to stay in touch and in the loop with their deceased parents partner until that partner dies which could be years. During that time they are responsible for half the maintenance bills- unless you state otherwise, but how will surviving partner feel about covering for say, a whole roof, when they only own half a house, how would the deceased parents children even cover half a new roof if they’ve their own house to manage? Or any number of even smaller maintenance jobs that need constant dialogue and discussion. Even if you write that surviving spouse has to pay all bills in a trust, what happens if they decline in health and stop being able to take care of house and value falls due to poor maintenance? What if the surviving spouse wants to move years later- how will the trust deal with that? What if they marry later post-loosing you? The children would need building insurance, they’d have to notify insurance company they don’t live there so may find it expensive. As part owners they’d have to work through council tax complexity as non residents in a property that’s not vacant. So many potential issues, aside from you forcing them to maintain relationships with their dead parents partner. And, because of that enforced continual contact, by doing that you may also be forcing them to take on care responsibilities for an aging and frail person they have no direct relationship to.
add to that they may, as far as HMRC are concerned own a second home. You need to consider capital gains not just IHT. when they finally can sell the asset on death of both parties, they will be charged IHT on difference of their share at point when it was valued for your probate vs sale value, maybe 10 or 20 years down the line. Capital gains allowances have been slashed and it is a high tax. Would what’s left after your iht, their capital gains and half house value really make it worth taking on that burden for years?
my dad is in this situation with a partner and no marriage ( not our mum, met her after mum died). He tried to create a stupid trust like this, that would have meant me and siblings needing to maintain contact with his new partner for the rest of her life. Whilst I don’t dislike her she’s not someone I’d be wanting to stay in touch with or bound to because of a stupid house after my dad dies. We just refused to let him do this, said just leave it to her. He did that. he’s now deemed mentally incompetent due to dementia and in a nursing home . She’s made promises that after she dies shell leave it to us ( she’s way younger than my dad) but frankly I doubt that and she’s assuming dads nursing costs won’t piss it all away anyway ( he is sole tenant so she’s left herself wide open to having no rights anyway but that’s another stupid story of theirs of burying their heads in the sand. She actually has a home of her own in another country so she can’t even claim she’ll be homeless 🤦♀️. ) .
whilst with good legal advice you could easily set this up, as a child of a parent in this situation I would run a mile from the burden this would place on me