Does the space used by app increase on updating?
If you are asking about the apps that came pre-installed with your device: Yes, their updates definitely will consume additional space, for a simple reason: The pre-installed apps are stored on the /system partition, which is read-only during normal operations¹ – so the update cannot be written there. Instead, it goes to the user /data partition. So with an update applied, there are always 2 copies of the app on your device.

You can easily tell affected apps when going to Settings › Apps and checking their entry. If it shows a button labeled "uninstall updates", that's a clear indicator.

All you can do in such cases is "disabling" the app – that is, if you don't use it anyway. Disabled apps are not updated, and already installed updates will be removed when disabling them. If at a later point you decide to enable them again, updates will be applied again as well.



¹ That usually means: always, except when applying system updates