Question: I have a uiview that has all my buttons, that has its controller. How can I include the button view in all my uiviews using the interface builder? The buttons must work when click. The purpose is to increase maintainability.

Answer: 
You can create a custom UIView in interface builder like this:
[Loading custom UIView from nib, all subviews contained in nib are nil?](https://stackoverflow.com/questions/7588066/loading-custom-uiview-from-nib-all-subviews-contained-in-nib-are-nil)

Then add your custom view to other views in IB by adding a normal UIView and changing the class to your subclass.
[Try this](https://stackoverflow.com/questions/2945910/build-xib-interface-builder-and-load-them-as-subview-in-iphone). I'm not sure that adding UIView in Interface Builder will work, but adding subview programmatically always works.