Most of people including the muslim have thought that only the mosque and madrasa is an Islamic architecture.
but in my opinion, Islamic architecture is more than that. because on Rasulullah's time, rasulullah also built the house and some part for muslim's businesses in order to increase muslim's economy.
On my opinion, Islamic Architecture is the art, product or buildings that contain of Islamic criteria or can easily said that a particular building have the functions for a Muslim to perform their duties and did not contain what Allah have prohibited in the Qur’an. and not a building which is only can a mosque or a madrasa. There are an islamic building for religion purposes, but how it is call as a Islamic architecture if there are many western and non-muslim and neglect the Islamic principles or laws on that building? Is it is still call an Islamic Architecture?
based on what i have studied, there are not only the mosque and madrasa can be indicate as Islamic Architecture, however, in my opinion, whatever that built in the sake of Allah, did not built more than sufficient, did not built for negative purposes such as showing off, haughtiness, and rivalry in building, it also can be considered as Islamic Architecture.
For an example, a house which is designed complete with the separation of men and women area, the toilet did not facing kiblat, have a privacy for the family, safety, and some other criteria that portray islam can be considered as Islamic Architecture.
Islamic Architecture is a huge field to be discover. We as a muslim should know what are the islamic principles or laws and applied it in all things that we do. We are creation of the Master of Creator, so why not we learn the knowledge about His creation and then learn how to create or built something in a better ways with the consideration of the environment and people at the surrounding.