An HD3D file is a project created by Home Design 3D, an application used to design or remodel homes. It contains project information, which includes a 2D or 3D floor plan with rooms, walls, doors, and windows. HD3D files may also include furnishings, decorations, and landscaping objects.

The HD3D project is the main file type associated with Home Design 3D. It is used to save a project and reopen it to make changes in Home Design 3D. HD3D projects can also be used to share projects with other Home Design 3D users. Projects can be shared via OneDrive, Dropbox, and email directly from the app or they can be uploaded to the Home Design 3D online gallery. NOTE: Home Design 3D is available in a Freemium edition, which is free but with saving and opening limitations, and Gold edition, which must be purchased. The Freemium edition is only available for iOS and Android devices and in macOS.