How would you feel about this arrangement?

[Pinkkahori]

MIL is nearing 70 and in fairly good health. She has lived alone in the family home for 10 years which although she tolerates I know she doesn't really enjoy. She worries about being alone as she gets older.
The house and garden she admits are gradually becoming a bit too much for her. Dh and I are renting. Due to unfortunate circumstances we didn't get on the property ladder pre-children and although we are financially fairly comfortable, buying a house seems a long way off.
Dh has recently started a new job which will mean he will be away several months of the year.
I think it could work well if we moved into his family home, used what savings we have and a loan to build an attached granny flat.
If we took over heating and electricity bills etc. it would free up some of MIL's income and make her life easier.

MIL has made passing reference to wanting a granny flat in the past in a way that I think she was making hints.
DH can see the merits of the plan but he doesn't know how to approach his siblings.
If we were living there we would save like mad with the aim of buying out his siblings.
Siblings are both home owners and MIL does not intend to sell the house. She is leaving it equally to her children so although I am sure they realise they will inherit it is unlikely to be very soon.

Sorry it's so long, trying to think of everything.
My question is if you were one of the siblings would you think it sounded like a fair arrangement?

Hi OP there was a thread on here recently about similar. It all became very complicated with regards to inheritance for the children of the other siblings and the consensus was to speak to sibs and see a solicitor!

Are you thinking of just moving into her house and paying the bills, who will the property actually belong to. If you build a granny flat who will that belong to. If it's all in mil name and she goes into care how will that be paid for. Id be wary if ideas a sibling that she is gifting you her house and may ask for the equivalent in cash, in the future there may not be any money left to inherit so siblings will have lost out. I agree with pp you need legal advice, there may be tax implications.

No, as I said we're thinking of building on a self-contained flat where she could live or we could, depending on what she prefers so that we could each have our own space but still be on hand if needed.
It would be with a view to taking care of her as she ages and we would run it as one household in terms of bills so she wouldn't be paying for heating etc.
We've only started to discuss it and we would definitely get legal advice if it was something she wanted to go ahead with.
I was asking on here to get a feeling what other people would think.
She doesn't have a great relationship with the other daughter-in-laws so I don't think it's something they would have wanted to do.

It sounds reasonable to me and if she is leaving her property to all her children, equally, not a problem - with proviso that you can stay there until you're fixed up somewhere else of course. You may even be able to buy her house eventually (my in laws did that with grandma's house, she lived in it with them It worked well, no aggro from siblings).

In the meantime, if you are able to save like mad, you could buy a small place to rent out.

A friend of mine has three siblings who had all "partnered up" and left the family home, while he stayed put as the location/ social circle suited him, plus towards the end of his DF's life, he needed a bit of an eye kept. When his (widowed) father died, the estate was shared equally among all four, and when he suggested buying out the other three, they came to an amicable agreement; I don't know the intricate details, obviously, but they sorted it out through the family solicitor, and the other three appreciated the support he had given towards the end of DF's life.
But this partly depends on how well the other siblings feel about it; perhaps they will appreciate the fact that this arrangement would benefit them as well?
Another friend told me that, although having DM in the "granny annexe" had its moments, it was definitely better to be on the spot to deal with minor issues before they escalated. A lot depends on how you all get along as a family.