A より　B （の）ほうが C です。
http://www.punipunijapan.com/yori-hou-ga/
It was stated in the above webpage that in the sentence pattern "A より　B （の）ほうが C です。" A and B can be nouns or verbs. It did not mention whether A and B can be adjectives or not. However, I found this example in the below webpage "大きいほうが小さいよりいい。"
https://answers.yahoo.com/question/index?qid=20120316194129AAs0lgB

Can A and B be nouns, verbs and adjectives?

Question

A より　B （の）ほうが C です。
http://www.punipunijapan.com/yori-hou-ga/
It was stated in the above webpage that in the sentence pattern "A より　B （の）ほうが C です。" A and B can be nouns or verbs. It did not mention whether A and B can be adjectives or not. However, I found this example in the below webpage "大きいほうが小さいよりいい。"
https://answers.yahoo.com/question/index?qid=20120316194129AAs0lgB

Can A and B be nouns, verbs and adjectives?

Answer

As you said, you can say 大きいほうが小さい(の)よりいい, but  大きいほう means "something bigger", so I think it's noun (or noun-like usage).

You can say 汚いよりきれいなほうがいい. It also means something clean is better than something dirty or being clean is better than being dirty. I think "something clean" and "being clean" are noun.