Tricky q about splitting assets in a non-marital separation

[Mykittensmittens]

I’ll try to be succinct. This isn’t me but I direct relative, DSis and her P

DSis and he bought a house together. Now have no mortgage. She owns 80% and he owns 20% this was all drawn up properly and done correctly.

they are now separating. They’ve done a bit on the house, paid for with relatively equal contributions, odd bits here and there over 5 years. General decoration, new downstairs bathroom etc.

the house has been valued and a sale agreed. As per the agreement he will leave with 20% of the sale and her 80%. She has agreed as a goodwill gesture to cover all the agents and legal costs of selling.

he is now arguing as they roughly equally spent on decorating and some improvements, he should get more than 20%.

does he have any basis for this argument?

All valid points

So he has had 50% enjoyment of a house that he only paid 20% cost of without paying her rent on a bit of her greater share.

Cheeky fecker.

I would tell him that he has enjoyed living in a house worth £300k having only contributed, what, £60k? And not having paid rent over xxx years on the share of houses that your sister owned over and above a matching 20%.

And that if he wishes to go through a lawyer it could cost him £10k… or more, if it might.

n.b I am not a lawyer

I agree with everyone’s points and we (she and I !) are very grateful, thank you. Relieving stress at an already stressful time.

He should have married her or had his 20k written into the house deeds.
How much are the house selling fees likely to be ? He could end up with less if he takes legal action or your sister decides to withdraw her offer to pay all of the fees. If he takes legal action then I suggest that she offers to pay 50% of the fees.