It seems then it isn’t really about the house at all but you feeling valued. You seem to have a pretty accurate assessment of the situation but are a bit unsure of your place. Like someone else, I think your OH is trying to give you a chance to make the house your own. Unless he actually wants to build the extension himself it shouldn’t take too long and you would be able to make it feel like your home without having to contribute financially at all - that’s the advantage of it being his home! I agree - with the minority it seems - that any future partner would not get any share of my children’s inheritance. Presumably any subsequent partner would have their own arrangements for their children, just have you have a (second) home which is benefitting your daughter, but there is no question that she is ‘avaricious’. In your place I’d prepare for a stormy discussion with his children, they have a point. No doubt they think your DD will inherit your house so why should they not inherit their DF’s house? You could always move into your home if OH predeceases you and your DD will still inherit it. On the other hand, if you help redesign his house how you want it you might both live there happily for many years. I’d have that financial discussion with OH first - I’d agree to share any costs that you living there increases, eg utilities and food, but nothing else. If you contribute to decorating, gardening etc he should agree that that has a value as, it seems, he is perfectly happy to do. And/or nominate a sum out of his estate in his will for you or to go to your daughter. Maybe you would want to acknowledge him/his children in your will? Perhaps if you feel secure that you’re actually valued as well as loved (he sounds lovely btw) there wouldn’t be any antagonism with his children.