How to split ownership of a house?

How to split ownership of a house? - 1
Added (1). My partner is putting down £100,00 and its being ring fenced with a deed of trust to secure it. So when we sell the property he gets that back. We plan on doing it up and selling it within a few months. How do we split the profits. We are having a £48,000 mortgage which we are paying equally and all expenses equally?
Added (2). My Partner thinks he should get a better percentage because he is loosing interest on his £100,00. I can understand his point but how can we do it fairly. Also current interest rates are so low and we plan on selling pretty quick.

Read more: How to split ownership of a house?