I am looking to get an Ipad and a web version of a home planning application. It will be very similar to
the main requirements are the 3D view, overview, wall and floor colors, movable doors (from templates ) and a few items that can be added to the design (bed, tv, chairs, table, plants...)
Only major difference is that the user will not be able to modify the floor-plans ( those will be inputted by the admin and the user will choose from those that apply to his project).
Take a look at the IKEA app. The layout will be very similar with column on the left and options at the bottom. each floor-plan has many rooms ( 3-6).