congrats yourself. a "little" boy, 10lb! fair play on the breast feeding, my wife swears by it, which is great for baby and me, i get loads of sleep.
I spoke to Stanley and they have informed me that regardless of distance from main house the flue would need to clear the pitch of the main house's roof. I didn't have all the details so I could not enquire further. My advice would be to get details like how far is flue from house, the height of flue etc and call stanley on lowcall 1850 302 502 and ask to speak with techincal. They also recommended a flue specailist company called MI Flues they are on 046 9558030, once you have your facts they should be able to advice.
The flue can be brought up by different methods but it may be pricey. Even in the building standards say to follow manufacturs instructions so whatever Stanley advice is the best course of action.
Good Luck