Indonesia is the most populous Muslims country in the world. The number of Muslims in Indonesia increase every time, it causes increasing Islamic facilities too and one of it is the mosque. The mosque is a holy building that is regulated in the Quran and Hadi>th. Related to that, the researcher tries to relate the hadi>th of building a mosque either construct a new mosque or just renovate with hadi>th of building the extravagant mosques is a sign of judgment day. The researcher selects Kangkung sub-district as the sample in this research about the increasing the number of the mosques. Kangkung sub-district has the religious citizens, so be the example to another sub-district in Kendal district. This religious citizen’s make the researcher doing research in Kangkung sub-district, so it may represent another sub-district and can explain how the citizens respond to this mosque construction phenomenon.
The researcher uses field qualitative research. It is done to the relevance of the text of the hadi>th and the real condition that exist in citizens. While the theory that be used by the researcher is Max Weber's social action theory. This research is the socio-anthropological research, so to understand this phenomenon relate with hadi>th about building extravagant mosques or not, the researcher needs a theory of social to understand interactions and motive between different citizens in building mosques. The researcher uses interview, observation, and documentation techniques to take the data and validate it. These three techniques are also used as a tool to validate data with the results from the three techniques that match each other. Finally, it can produce a valid research result.
Through the stages of techniques and steps that have been determined, the researcher concluded if the mosques construction and renovation on Kangkung sub-district are not extravagant mosques on the average. This is caused from the sixteen mosques as a sample that researched there are thirteen mosques that were constructed and included in rationally purposeful action (Zweckrationalitat), according to Max Weber's social action theory. It means the mosques construction and renovation have clear purposes and values and there are just three mosques on Kangkung sub-district that include effective action and include extravagant mosques because these mosques are constructed or renovated to extravagant with other building or just follow the era or the other mosques.