Design a drawing program in Flash

Project is to make a function where the customers can -construct- their own very small cabin. The cabins are only 20 m2 - 4 walls and a roof. On this they should be able to decide the width of the cabin- and the lenght of the sides. Cabin is made of sandwich panels 1100 mm wide each. They should be able to drag panels into the drawing - and -build- the cabin. Then they should be able to drag standard windows and doors into the drawign - place them where they would like. The finished result - with measures preferably automtically generated - they should be able to save and send as e.-mail attatchment. It will be like an order drawing one can build these cabins from. Have sample from near similar Flash program already made