Broderbund company is probably best known for jump-starting the 'consumer level' home design software industry with their landmark 3D Home Design Products: 3D Home Architect®, 3D Home Architect Deluxe, 3D Home Design Suite, 3D Home Design Kit, 3D Home Landscape Designer... originally produced by the folks that create Chief Architect and later by the folks at CADSoft.
Version 5.x of 3D Home Architect is NOT a direct upgrade of previous versions. It is a complete rewrite of the software based upon the Envisioneer CAD engine from CADSoft. The new program has a different interface and it is not compatible with files created in previous versions. Versions 3.x and 4.x were produced by ART using the Chief Architect engine. ART does offer a compatible upgrade to 3D Home Architect version 4 called Chief Architect Home Edition 5.0, which is available through their Web site.