Hi Vicky,
Oh no, he's not giving me half of his house. When I settle up in the US and move to England, I'll have a large sum to put towards the mortgage, so it will be fully "our" house. I'm sorry I didn't include that in my original post.
Since the money he already put down in addition to my money will leave us very little mortgage, perhaps adding my name to the mortgage/refinancing would be unnecessary. Good point.
However, could my name still go on the deed once we are married (even if my name is not on the mortgage)?
Thank you!