I looked at all the sofas that people built and took bits out of a lot of them to decide what I needed to fit my needs. I am in a tiny house and I wanted the sofa to be super versatile as well as being good for storage. I decided to build it the size of a double bed, but to divide this into three sections so that it can be used as a sectional, a seating area for meals and a bed for overnight guests. It was a lot easier than I thought it would be.
Thank you for this, I would not have known where to begin.
I decided on brightly printed outdoor fabric because the interior of my tiny house is all wood and I though the bright colours would be a nice addition. The outdoor fabric was chosen so that it would resist water and stains as well as pet hair.