The following list of free house design software packages are useful starter applications that can help you map out the design of your home. Unfortunately the old addage that the best things in life are free doesn't apply to home design software! You get what you pay for.
Below is a list of nice free home software packages. I've done my desk to describe each one briefly. Its work checking these out before you pay for a professional software package so you can get a feel for what you like/don't like about this type of software.
Google SketchUp 7
Google SketchUp 7 is free tool developed by Google. While its not specifically a home design software program, it allows you to quickly 'sketch up' a 3D model of your home. You must start with a template and alter it to the design that you desire. SketchUp 7 gives you access to the Google 3D Warehouse of designs that you can edit or incorporate into your house design.
Google SketchUp 7 is the free version of Google SketchUp 7 Pro which costs about $495.
Design Workshop Lite
The full free package of DesignWorkshop Lite software package offers you a lot of tools to build your own 3D home design models. This also offers you the ability to visualize the architecture and landscape. By using DesignWorkshop Lite you can walk through, pre-made models of varying size.
AutoCAD was developed by a company called Autodesk. They offer a free version which can be downloaded from Download.com. Its hard for me to review this home design software package as it is quiet complicated and takes a lot of time to get used to. Suffice to say that it has a great user interface with lots of features. The professional version of this piece of software is quiet expensive and retails around $1000.