The floor plan was not engineer designed or engineer stamped after design. We used these plans for the purpose of working with our building consultant to have the shed company correctly place the door and windows and to order all of the material for the build out(each square represents one square foot.) These plans were also used as a basis for determiningplacement of walls, stairs, cabinets, shower, toilet, etc. but there were small tweaks and changes along the way to make it all work. Any skilled carpenter should be able to use these plans as a base to create the custom cottage of your dreams.