‘as well as’
‘As well as’ can only be followed by a noun or +ing form.
It cannot always replace ‘and’ because it cannot be followed by ‘SVO’ sentences (Subject-Verb-Object)
‘The number of houses has increased as well as more roads have been built‘.
‘The number of houses has increased and more roads have been built’.
‘The number of houses has increased as well as (the number of) roads’.
NB The same is true for ‘In addition to’ and ‘together with’.
e.g. ‘In addition to/As well as/Together with the increase in the number of houses, more roads have also been built.
‘More houses have been built, together with/as well as/in addition to more roads’.