Perhaps you do interior design or home remodeling as a profession or you need to change the layout of your office occasionally. It is always helpful to be able to do the new layout and visualize it from all angles. This lets you look at all the possibilities in advance and tweak your design before buying the actual furniture or moving the existing ones. Previously, in order to do this, you would have bought expensive software that only high-end professionals could afford. Now you can use free open source Sweet Home 3D.
Via Ashok Ramachandran