If you look at the descriptions of the buy items it will tell you the environment 'rating' but there are also many items that will have an emotional aura. Items that have just environmental auras will give a sim a 'happy' emotion or a 'Very happy' emotion.
However, like shewolf said, sims in ts4 do not notice unfurnished, unpainted, unlit or even incomplete rooms at all. But they will notice dirty surroundings and 'good' surroundings and their emotional moodlet will show this.