Ash's apartment is within an apartment building in Sing. It is the home of Ash and the former residence of her ex-boyfriend Lance. It is located next to a laundromat and a hotel.
It is first seen, when Lance is singing a song while playing the guitar as Ash brought popcorn. Ash tried to get Lance to understand that she wants her opportunity to be for the both of them, but Lance refused to listen, calling her a sell-out in his "song".
The living room can be seen in a later scene where Ash and Lance laugh over the cheesiness of the songs Buster Moon selected for her to sing in his show.
It is later seen again as Ash walks in to find Lance singing with another girl. Ash kicks them out of the apartment, along with Lance's belongings, before sinking to the floor in sadness.
In a later scene, Ash can be seen in the process of writing "Set It All Free" as ripped photos of her and Lance are shown laid across the floor, using their break-up as inspiration for her song.