I want to make my 12x24 wood building into a small overnight guest house....?

how can I do that? In that small space how do I design and make the most out of the space? I want a small bathroom and kitchenette ...please help...thanks!I want to make my 12x24 wood building into a small overnight guest house....?
First check with your city's code enforcement department to see whether they will allow the conversion and what they will require. In our city, the codes require a certain square footage for both bathrooms and kitchens, certain electrical and plumbing requirements, insulation factors, fire safe roofing, venting for kitchens and baths, windows, and a host of structural requirements. Then head over to the building permit department and see what their requirements are, like what permits they require, what inspections they require and building fees. The requirements will either greatly limit what you are able to do or give you direction in what you can do.I want to make my 12x24 wood building into a small overnight guest house....?
does it need a heater? you dont want your guests to freeze over
Get lots of functional peices day bed, convertable sofa. In PB Teen they have a ottoman that converts into a twin cot, probably not your style but you get where I'm going. Also it be cool if you had an island that converts into a kitchen table.