The best Interior Design alternative to Rhinoceros is FreeCAD, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to Rhinoceros and three of them are Interior Design Apps so hopefully you can find a suitable replacement. Other interesting Interior Design App alternatives to Rhinoceros are SketchUp and DDL - Digital Dry Layout.
Rhinoceros alternatives are mainly Interior Design Apps, but if you're looking for
3D Modelers or CAD Software you can filter on that. Other popular filters include
Free,
Linux,
Open Source and
iPad. You can also filter by region, for example
EU-based alternatives if you prefer software developed in the European Union. These are just examples - use the filter bar below to find more specific alternatives to Rhinoceros.
FreeCAD interface is less intuitive than some of the alternatives, but it mostly works. Overlapping fillet operations, however, can break down where other CAD software operates just fine. FreeCAD should be ok for simpler projects.