We were asked to add a 1000 square foot second floor to half of an occupied  bungalow. We were creating 2 new bedrooms and a bathroom upstairs, whilst completely refurbishing downstairs, including plastering throughout. We built the entire first floor in our workshop and yard. This made it possible for us to take the roof off the existing building, lift the preconstructed new floor into place, and construct a new roof in under a week, making it completely watertight in a short weather window.  This job was brought in on time and on budget.