Hi I wonder if there's any economical solution to adding a 2m x 2m garden/storage room in the backyard. The room will need to be completely weather proof since we're hoping to store items like luggages, beddings, violins, old computer, etc. I was looking through the internet and found Designs - Backyard Room but their lowest end option costs around $20k! My budget is just $1500. Can anyone suggest a way I can add a storage room, with minimal fuss? Thanks!