Common area Issue - Apartment

Hello Sir, There are 6 flats (with ground, first & second floor) in our apartment and all have separate parking space, with each gate in the parking in the ground floor. The builder has put on single common tap on one end of the building and the other end, new tap was fixed 3 yrs ago with through maintenance with all owners share. New tap was fixed in the wall of the building and water gets scattered in one of the owner's parking. After yrs of time, this owner has removed the tap completely as the water scatters and replaced with 3 different taps separately. This was not informed to 2 of the owners of the apartment and for 3 ppl convenience he has fixed. Similarly, he has removed and altered his parking gate for his individual purpose. When asked, why these common utility has been altered without any notice to others, it was said that it's there gate in the parking and will alter as per the wish. I need to know if the gates for each 6 owners parking can be altered for own's purpose and does this not comes under common utility. All the other 4 owners are quiet let him do whatever wants as his gate and tap can be altered. But this is against the apartment rule.. If we convey , no one is open up to question.. How to tackle this issue, even the builder who constructed the flat is not bothered on these. We tried reaching him to inform on the common utlities in this flat but failed. I'm worried if this continues, then 4 - 5 people benefits will be considered to go which is against ignoring the other owner.