So I had a disagreement with a friend of mine in translating a sentence into my mother language. I wonder if it has 2 meanings. I'll give the following 2 sentences too for you to understand the subject and also because they might effect the meaning of the sentence I want translated. Here it is:
According to the documents which list his works, he designed, supervised, built or restored as many as 400 buildings. But if we consider the fact that he was in charge of the Imperial Body of Architects and the hugeness of the Ottoman territory, it becomes difficult to believe that all these works were directly produced by Sinan personally. However, with the exception of those built towards the end of his life, the buildings erected in İstanbul can be assumed to be his.
So the sentence I want translated is the last one starting with "However". My friend says the sentence means: Except for the buildings built towards the end of his life, the buildings erected in İstanbul can be assumed to be his. And I think it can also mean: The buildings erected in İstanbul can be assumed to be his because of the exceptional (eg.) design and structure etc... Now, the first translation seems to be true but the reason I think it should be translated like the second one is because the sentence starts with "However". So it has to contradict the following sentence. And the following sentence indicates that it is hard to believe that all the buildings were built personally by him. So the sentence starting with "However" has to contradict that... And if we translate it like my friend did, there would be no contradiction. And also why would the sentence compare time (towards the end of his life) and places (the buildings erected in İstanbul). I am sorry for bad English and long question.