In article , Dave Plowman (News)
writes
In article .com,
wrote:
Surely this would depend on whether it's an internal type or external
'add on'?
Still cant figure out what you mean 
Many modern semis have built in garages - often adjoining - where both the
walls and foundations will be the same as the main house. A garage which
is simply an addition to the side of the house may - or likely not - be
built to the same standard.
It would be sensible to check the original planning consent. Where *on-
street* parking is an issue there may be a restriction on such a
conversion.
regards
--
Tim Lamb