The options available for drawing floor plan in C# are
The following books may be helpful to write a program or general purpose library in C# for drawing.
Practical C# Charts and Graphics book for windows forms
and if you want to develop the library in WPF then
Practical WPF Charts and Graphics book
Details about these can be seen at
If the requirement is to draw a simple plan without many details, then I think the drawing can be generated with graphics with the help of above books.
It is a time consuming and tough task, if a full fledged library having options like Dimensions, layers etc as found in AutoCad is to be developed.
can be used to draw to AutoCad
is a very good library to draw drawings.
] is another library for drawing
] is a library like Visio for drawing