هذه غرفةُ جلوسٍ قديمةٌ

"This living room is old" should be accepted.

Salon and living room are the same word?

I am Egyptian and we use the word صالون for the room we keep for the guests and أُطْ المعيشة for the room we usually sit in. But the living room as an idea and a word is taken from the west and translated literally from English; a modern thing.