I would be doing everything to own the house on my own. On average you will get a 60/40 split (maybe 65/35). I would be talking to a mortgage broker (it's free) to get an idea of things. I don't want to be negative but things may not be so amicable in the future. You may be surprised in that your repayments may go down if you restructure well. I currently have a 'boarder' who helps pay my mortgage. This means I don't have to work so hard whilst my dd and ds are so young. Once they are both at school I can work more and afford the mortgage without a boarder there. Let me know if you want the contact details of my mortgage broker. I've used him for many years and he's worth his weight in gold.