Does the space used by app increase on updating? I'm working on Samsung Galaxy On7, Android 6.0-Marshmallow. Many apps like MS excel and word comes inbuilt, so I cannot move them to sd card, and they are taking up huge space on the phone memory.

Now, b other of these apps have released updates of size about 50MB. The mobile data is not a problem, but will the size of the app increase if I update it? If it increases,  then I cannot install the updates.

I tried contacting the app developers but got no response from their side. So, it'll be very helpful to me if anyone knowing this can explain the bit.

N.B.: I don't have a rooted phone, and nor do I want to root it, and thereafter use apps like Link2SD.
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