Please don't omit the context and the full sentence. So is this the full sentence you are asking about?
Then it means "Among 衣食住, 住 is the hardest". 衣食住【いしょくじゅう】 is a compound that refers to the three basic necessities in our life (衣 = clothing, 食 = eating, 住 = sheltering/housing/housekeeping).
住まい refers to the same thing as 住 here. Since 住 is a short on-reading which makes little sense in isolation, this person rephrased it as 住まい, which is a wago that means the same thing.
But what this 住 (= 住まい) actually translates to depends on the context. It may refer to buying a new physical house, or it may refer to housekeeping jobs such as cleaning. The sentence may just mean "I like cooking but cleaning my house is a hard task to me".