Don't think there's a financial answer to this

I think you need to find an option to live separately. Each family must live separately and cost their relationship independently

It does depend upon whether or not she put any money into the refurbishing? If she didn't, and it doesn't sound as though she did, then carry on with your plan and move somewhere cheaper, taking her with you. Tbh, you didn't create luxury accommodation just for her benefit.

Help your daughter and GS with some of the Money.

I hadn't thought of it like that, Daisymae but you are quite right. And, JenniferEccles, "money can only be spread so far" is quite right too. I feel as if everything is on my shoulders sometimes - I'm one of those people who takes on everyone's problems but know I shouldn't. Thank you to everyone. Jenpax, I will phone the local council to see if they know of anything. All ideas much appreciated.

Would your daughter be able to look for a better paid job to enable her to move to a nicer flat?

I appreciate that you want to help her but you have a lot of responsibility with your elderly mother and money can only be spread so far can’t it?

Good ideas here, you seem to be responsible for the housing of 4 generations, no wonder it's difficult to sort.

You mentioned some savings. Have you looked into a shared ownership property for your daughter? This would allow her to own a part of her home and rent the remainder (at often less than the private rental rates) The savings you have could either pay the deposit, and she get a mortgage on her owned share, or pay for her share and she rents the rest from the Housing Association who would run the scheme; lots of housing associations offer these shared ownership schemes, and the properties are usually new build so in mint condition.
A First step would be a call to the housing officer at your council to ask if they know of any current local schemes.

I have a friend in a similar situation. She provided a home for her very poorly mother. With company and super care she has flourished. My friends health has broken down. I think that your husband has the right answer. Go ahead with your plans and get her to fit in.

Some friends of ours in a similar situation spoke to a financial advisor who came up with some kind of clever equity release arrangement. I don't know all the details but they are happy with the solution. The mother is now 99 and going strong!

PS: it occurs to me that if mother owns her own house, but doesn't want to put its whole value into your 'pot' then she could consider renting it out and contributing that.

It seems to me that a 'family conference' is needed to see what might suit everyone and what financial & other contributions can be put in to the pot.
By 'other' I mean caring responsibilities, work on the home etc. You are obviously capable problem solvers, but you need the other generations to contribute their bit. You don't mention the geography, and whether you would move near your daughter, or consider a large house together. A fit adult and a teenager should be able to fit some work on/in the house around their work and study.

There are lots of ways of buying and willing property jointly, that you can get advice on. However, it seems that you think moving with mother is unrealistic, and your DH doesn't. So you need to sort out your feelings about this (including providing 'hotel' care!).
I hope you can sort something out.

Give your mother's contribution to your daughter-

x posts Chestnut

Well there probably isn’t an answer that will suit everyone. What happened to the home your dm was living in prior to coming to live with you? I guess it was rented. Are you saying that it’s unrealistic to move her with you because you can’t afford a house big enough if you need enough left over to help dd? Can dm really not go back to living on her own as she was? Have you spoken to her about the awful situation your dd and dgs are in - no desk or table how sad.

You didn't mention what became of your mother's home. Was it rented (in which case she now has some extra income) or did she sell (in which case she now has some extra capital). The practical solution is therefore for your mother to pay for living with you and that money be used for your daughter's home. You need to explain to both what your intentions were and why this is consequently the best solution. If your mother refuses to help then tell you you'll have to go back to your original plan and sell up! And where will that leave her? She should realise she is getting a very good deal here and needs to pay her way by helping your daughter.

Can you help your daughter find a nicer rental place?

That at least would give you some peace of mind until either your gs goes to university, or work.

I know nothing about capitalising on a mortgage but I'm sure others will. It may help her with a deposit on a small apartment.

Here in NZ, apartments are becoming the next big (good) thing to buy into, rather than free standing homes. They have less maintenance, less rates and so on but increase in value over time.