Add a backsplash from countertop level settings

Add a backsplash as a countertop-level modification, set its height and shift it up, and keep it from running behind the tiles.

1. A backsplash is added as a countertop-level modification.

   ✓ Checked in the product on 20 October 2026

2. Set the height (100 mm is a typical value) and shift it up.

   ✓ Checked in the product on 20 October 2026

3. In the extension options set the back extension to zero so the backsplash does not run behind the tiles.

   ✓ Checked in the product on 20 October 2026