Yep, did this years ago with a friend, we split the house price three ways, his parents threw in a third as a deposit and we had a lodger to cover their part, we had the rest as mortgage 50/50, six years later we sold up and went our separate ways. I was 21 when we bought the place and I walked away with a decent chunk of money which was enough for a deposit on my own place, it wasn't all plain sailing and living with lodgers and messy noisy housemates was at times trying but I'd absolutely do it again if I needed to.