Architectural Designs

Could you suggest a free software to design home (3D)and to download? I am planning to construct a house and i want to design the same as per my aspirations.

Can somebody help me find a home designing software? Does anybody know of any free and easy to use software I can download that can help me build any kind of building I want, and shows how much it will cost me. Anything close to that will help me a lot. 3D projections would be helpful but just the basic floor plans would work too. Just as long as it shows how many feet.

What would I need to use for this???? I am looking for a computer software program that will allow me to make a 3d plan of a project I am hoping to build. It would help me with finding out the exact measurements I am looking for in the project. And will allow me to go as far as painting and designing the project in the software to see the finished look. I know there are different software to do this when you are builing your own home, but what about simple carpentry projects like I am looking for??? If there is a free trial download even that would be nice to try out, but I am open to looking for programs you need to actually purchase as well. Thank you!