Should I let my daughter, and family, live in my house?

Why aren't they able to arrange their own accommodations?

As you’ve already extended the offer, it’s rather late to consider the repercussions.

Difficult for you. As the offer has been made it would be very hard to back track. Clearly you have missgivings about your daughters partner, that is a red flag for you. I think you need a very frank discussion with your daughter, set a time limit as to how long you can accomodations them , talk about a reasonable cash contribution too. I have no experience in situations like this but wonder if citizens advice bureau might advice or perhaps a solicitor to help you draw up a contract. If you go ahead it will be hard in a small house , two adults and two children! Please protect yourself in the best way possible.

Is your daughter considering buying another house, or are they not in a position to afford one and intend to stay with you to recoup losses?
The partner's money problems sound worrying, and also his behaviour.
You have to establish a time limit, and also a realistic financial contribution otherwise you will be subsidising them and they won't move on. Do it before they move in, and make sure you mean it; it also gives them time to think hard about finding somewhere else.

Unfortunately these are things that should have happened before you offered.

Are you sure they don’t have other plans?

You can always say it is not going to work out, whatever it is, before it happens.

I would personally extend an offer like this after the rules of cohabitation have been discussed and agreed
You already mentioned concerns in your OP - please be smart

Living together can impact relationships very much, even more than rethinking the arrangement now.

I think that if there are unmentionable aspects of your SIL's behaviour that concern you it would be wise not to make this offer!

I wonder what they intended to do when they sold their house? Rent whilst they are househunting? Downsizing? Do they even intend to stay in the area?

I think you need to make it clear that your offer comes with conditions, which need clearly laying down, and probably a signed agreement.
It is not something I would do, personally.

Has the sale of the house gone towards clearing his debts?
Alarm bells are ringing in my head.
Well you don't want the children homeless but your daughter needs to be careful.
Do you own your house outright? Or have a mortgage?
We live with daughter and 2 children and it can be challenging at times.

Luckygirl3

I think that if there are unmentionable aspects of your SIL's behaviour that concern you it would be wise not to make this offer!

Hear, hear!

But if you do take them in, they should pay rent and for amenities like electricity.

To be honest, my initial reaction to your question in the title was "God, no!"

If their children are at school, would they be better renting in the catchment area where they intend to buy?

If they had to move schools if they moved in with you, then again when she buys a new house that would be three moves, provided the school could take them of course.

You could use that as a sensible point against them moving in with you.

It’s only a temporary arrangement so my advice would be to relax and have fun.
No idea why everyone else has jumped to such negative conclusions.

semperfidelis, as your daughter has sold her house, I assume that she has funds to pay their share of the bills. Make an arrangement with her to pay in advance - being very clear about the amount you expect. I'd set a firm deadline for them to move out, too.

what will you do if they don'y move out.
and beware of cuckooing.
you will be outnumbered, and being older maybe less able to stand up for yourself.
will it impact your house insurance.
and you will lose council tax single person reduction.
just email them, sorry, you are unable to accommodate them.
least said, soonest mended. only apologise for changing your mind. do not discuss reasons. broken record: repeat.

As you have already offered semperfidelis it will be difficult to back out. You need to set a time limit of how long they can reasonably expect to stay. Its not too late to set some ground rules about expenses, privacy etc.
You may well find things are not as bad as you anticipated and it will be good to spend time with your grandchildren.

Semperfidelis, I think the success of your kind and helpful offer depends on your own strength of assertiveness. It's up to you to make the house rules and check the rules are kept. Best wishes.

In the event it will probably be a mixed success as are most practical compromises.

I can’t see this working well, you have misgivings about your daughters' partner, who she is presumably happy with.

The partner has not said how he feels about the move so you don't even know if he is happy with the arrangement.

It is going to be difficult for them if you are not fully accepting of your daughters' partner leading her to take sides.

I’m concerned about the ‘aspects of the partner’s behaviour’ that OP doesn’t want to mention. She’s said he had financial problems which he tried to conceal so there’s something more serious in the background.
OP will be considerably outnumbered and could become marginalised (and possibly abused?) in her own home.
The daughter has already sold her house without finding somewhere else to live. What mother does that unless she has no money to buy or rent another property? It sounds like a forced sale either to pay her partner’s debts or because she hasn’t been paying the mortgage. She may well have little or no money left from the sale and the search for another property could take a very long time. If they are comfortable at OP’s home and it’s cheaper than the cost of living in a home of their own, what incentive will they have to move?
Don’t do it OP, even though it means going back on your word. Tell your daughter that, having had time to think it through carefully, you don’t think it will be a good arrangement for anyone. Difficult but for your sake please do it.

It's difficult to comment, as there's not really enough information in the OP.

Your daughter has sold her house. Why?

They have nowhere to live now. Why?

Your son in law has serious financial problems in the past. From what?

He concealed these difficulties. Why?

Does his financial past mean they can't now get a mortgage, or won't be accepted for a rental agreement?

Your son in law hasn't ventured an opinion as to whether he wants to move in with you? Why? Has he been consulted, or have you and your daughter made this decision?

Your house is small, you say. How small? Is there physically enough room for you all? Can your home accommodate four additional people?

Where will their belongings be - are they bringing those with them, or putting them into storage?

The most concerning part of the OP, because of lack of information, is the "other aspects of his behaviour". This could be anything from alcohol misuse or drug misuse to coercive control of his wife and/or children. Would you be comfortable for these behaviours to continue in your home?

You say you wouldn't want much of a financial contribution, but have you actually considered how much having four additional people in your home will cost? Additional heating, lighting, water, food? I understand it would be uncomfortable taking money from them, but to be honest, you don't want to make them too comfortable, and not want to move on.

wellbeck has made some good points in the post above.

I would be very wary of having them move in with you, unless everything is agreed and put in written form. And even then, I personally would be saying "sorry, it's just not feasible".

OP

You could still help them w/o having to house them - although enabling is pretty much an issue we have to consider here.

Say no and avoid a headache in the future

With this vague background, you could offer certain amount of money for 1 to 3 months till they get on their feet, for example

Rescuing them from what it seems a very badly managed situation is not advisable

Why didn't you talk all these matters through throughly with your daughter and her partner before agreeng to this.

I think all you can do now is make it clear to your daughter and partner that this is a temporary arrangement only and they must move out after 6 months.

Bad idea say no...

Absolutely not. You will never get rid of them and as others have said, why do they not have eg rented accommodation to move into if they are looking to buy somewhere else later.

Please, please say no or you will regret it, especially if you allow them to live there paying very little towards the bills.

There are too many unanswered questions. Please say no.

Why did your daughter sell her house in the first place? Has she got any collateral from it? Were there debts?

The partner sounds a risk to me, especially as there are points you can’t discuss.

Why not just say you’ve thought about it, and you now realise it’s not such a good idea to have all of them. Still offer help to your daughter and grandchildren. There’s no obligation at all...but certainly isn’t to him, as they’re not married.

I would worry once he’s settled in your home, he won’t bother with anything. If he has to sort himself out, he may see it differently.

Don’t do anything that makes you feel uncomfortable in your own home.