Create 3D Building Internals from Rough Floor Plan

I am looking to have a rough floor plan that I require be created into a 3D Model for use in Unity 4. I have a rough floor plan that can be provided. The environment is 34meters by 70 meters. However the bulk of it is the same design repeated. The design is based off an actual building here on the Gold Coast (Was a Cinema back in the 80s) so I only have a few photos and basic measurements. I will provide some materials and color guide. I would like to do this in 3 stages. Depending on how stage one goes you would be given the additional two stages as well. 1) Walls, Floors, Roof, Doors, Windows 2) Textures, Furnishings 3) Tweaks to Design additional Furnishings The building internals feature the following... 1) 3 Window Ticket Booth 2) Male & Female Bathrooms (x2) - Furnishings are just basins and stalls 3) Small Candy Bar with Drinks Fridge, Ice Cream Fridge and usual candy bar stuff 4) Small Rooms (x4) - No Furnishings required as these will not be player accessable (yet) 5) Theatre Rooms - I will provide a mock for these but they dont need any furnishings till stage 2. My main focus is on the foyer/lobby area. I want to get this right before I focus on the theatre areas.