To not want my MIL to move into our annexe

I still wouldn't buy it, based on the update.

Definitely not. And I would address why he doesn't want to spend time with your parents. He doesn't sound very nice.

Do not let your MIL move in. This happened to a friend of mine. There was a big discussion beforehand about just because she was staying in the annexe it did not mean they were 1 household and they would live separate lives but despite this…..!
The MIL nearly called the police when my friend was late home from work as she had popped in to see a friend. The MIL planted plants in the garden, then moaned at the kids playing in it. The MIL became ill at the end and despite having carers 4 times a day, it still meant my friend had to do loads of personal care. The MIL did not want her son doing this. Every time the MIL had a visitor they would expect to be given a drink or even a meal. When my friend’s SIL visited she would send her young children to the main house for my friend to look after. My friend always speaks up for herself and her husband is very supportive but it still happened.

Looking at the potential future outcomes for this the majority of them end up in you being live in carer for your MIL.

If that is not an outcome you desire I would look at the other options available.

How old is your MIL?

I would either:

ensure the annex is removed and the house made whole before you even move in

or

buy a different house

if you don’t do one of these two it will continually reappear and your position will be MUCH weaker if living in the house with an empty annex

Agree, it is hugely unfair to accommodate her and yet he can't stand your parents. Besides you must know her future care WILL fall to you somehow. I think you should fight this now rather than later. It might cost you the marriage but at least you won't have a house to sell then!

My parents did this and it ended their marriage.

I completely understand your concerns and agree with many of the risks highlighted here. However, I have a slightly different view overall because if we had an annex, MIL might well move in with us, even though I can't say I'm her biggest fan. But then, I am actually very confident that DH would 100% take on the caring (th ebigger issue would be him spending too much time helping her vs me/the DC).

But I think the resentment factor is important here. You say that you think your DH's attitude to your family is unreasonable. You haven't said why he hates them so much so it is, of course, impossible to assess. But I'd sy that unless you resolve that - either accepting his reasons and respecting them or him accepting he's wrong - you are always going to have this issue in the context of his family.

This!

And it’ll be a nightmare if she ever develops dementia.

I think I'd have to say that the house purchase fell through due to a higher offer. I would just find something else honestly. That saves all the hand wringing and guilt (husband's maybe), and compromise, and all the rest of it.

It's too big a thing to work out. Maybe keep looking and find MIL somewhere in sheltered accommodation or over 50s which I think are relatively easy to come by now.

THIS....You will become her carer, no matter what he says.

Don't buy that house.

You would think that would happen but in reality..

Your MIL has wet herself because she couldn’t get to the toilet. Which one does she want helping her clear her intimate areas? Not her son.

You really see the sex differences when it gets bad. When MIL was dying it fell to me and SIL - there was no way she was going to have men doing what needed to be done. My DP and his brother were terrified and had no idea what to do.

Sounds as though the possibility of her moving in, and therefore being there long term, makes this a no-go as extending/incorporating it into the house would likely never happen if she moves in. You could hardly give her notice 3-5 years down the line because you want to get on with it, could you? Moving her in WILL be permanent and you will lose access to the annexe space forever.

Totally feel for your DH, but I think he should consider stating that you had only considered airbnb-ing the annexe or doing a couple of short-term lets to fund the building work you envisage to incorporate it into the house… then work with her to find an alternative rental.

God that sounds awful, sorry! I'd rather have a stranger as I'd feel family member would be coming in my house and personal space all the time and that would be awful !
It will also end up being your responsibility I'm sure as the other children would assume you guys are doing everything

You think there’s a chance that you might not end up as her carer, being the closest adult female in proximity? lolololol 😂

I'd choose a different house. Which is a shame as I think a separate attached dwelling is a perfect bit of space for when you need to decompress from the world.

I'd probably agree if it were my mother in law, but so would my husband if it were my mother. It's not connected to your house and you just need to firm up boundaries. However, if your dh can't manage an hour with your parents I'd point out that it's difficult for you to agree to live with his as it's unfair on your parents but should your parents need assisted living in future you'd have to offer them the same... See what he says to that?

Urgh, why does it always seem to fall to the female partner to shoulder work, kids AND elder care? What the hell is wrong that HE can't be the one to shoulder his mother's care? My step dad is trying to force my mum to do the same, as if he's somehow not supposed to be the one responsible to care for his own mother.

Absolutely not!

You would end up as her carer without a doubt.

In fact for me it would be a divorce situation if a partner tried to push this scenario on me...

This - if you don’t need the annexe (ie weren’t planning on knocking through and enlarging the space), I’d pull out and buy elsewhere. If things were equal - the annexe would be available at some future date for your parents, if you both got on with each sets of parents, it would probably be workable with clear ground rules and an iron clad undertaking from DH that her ongoing care in the event of declining health is HIS responsibility… but as it stands I think this could have huge implications for you marriage in the future.

(And I say this a someone who loves her PiLs to bits and would happily have them move in and stay with us if their needs meant they were safest with us and/or it gave SiL a break. Difference is, we’re seriously very close.)

However, if MIL does need help, she will be nearby.
My MIL lives in our annex and i hardly see her. Husband or kids sees to her needs

I might consider it if I was 100% confident that I could make sure I didn't have to lift a finger for her and everything that had to be done for her would land on his head. However he will have set things up so that everything lands on the op's head so she will have to have a good strategy in place to out maneuver him

What are your husband's plans for supporting his mother, especially as she grows older?