Short answer
Generally, Islamic law places the responsibility of providing reasonable maintenance for the wife upon the husband according to his means.
Islamic Guidance
What Islam teaches
Nafaqah includes reasonable living expenses such as food, clothing and accommodation according to circumstances and ability. The exact details can vary according to Islamic jurisprudence and circumstances.
Practical Guidance
What you can consider
Discuss practical arrangements clearly before marriage, while understanding that voluntary contributions by either spouse should not be confused with the basic legal responsibilities established by Islamic law.
Sources
Qur'an 2:233; Qur'an 65:7; Sahih al-Bukhari.