"Cosmetic upgrades" refer to improvements or changes made to the appearance or aesthetic features of something without necessarily enhancing its functionality or performance. Full definition
When we first walked through this house, there was no doubt we would have our hands full with cosmetic upgrades, if we chose to buy it. (apurdylittlehouse.com)
A vehicle facelift is usually never really «exciting» unless you have some kind of mechanical changes instead of just minor cosmetic upgrades. (auto.ndtv.com)
The buyers thought they were getting a modest house that needed a few cosmetic upgrades. (realtormag.realtor.org)