The 0.5m gap they require is utter bull$hit.Thanks for the reply just had a reply from the council they me to do the following:
At present, the side wall of the extension will project from and adjoin to the existing garage which is deemed to be a side elevation. Moving forward, the side wall of the extension will have to be set away from the side wall of the garage by 0.5 metres. If at any point the two reach, the extension will become a side and rear extension with a width greater than half of the width of the dwellinghouse which will continuously fail under the prior notification scheme.
Similarly to the above, the height of the extension would need to be reduced to allow a 0.5 metre separation between the roof of the extension and the bay window that serves the first floor rear elevation of the property. This is because bay windows are deemed to contain side walls so if the extension projects off the bay window (i.e. the extension crashes into the bay window) we will be left with the same situation as above.
There are appeal cases where a gap of 25mm is deemed OK; as long as there is no physical connection between the side and rear eaxtensions, they will have to accept the prior notification.