The sentence

> Except the buildings built towards the end of his life, the buildings
> erected in Istanbul can be assumed to be his.

was recently used in a question here.

I edited to replace 'except' with the compound preposition 'except for'. I'm very unhappy with the original, but don't like to assume my gut reactions are necessarily correct.

[CDO](http://dictionary.cambridge.org/grammar/british-grammar/except-or-except-for) gives:


> *Except or except for?* from English Grammar Today
> 
> We often use *except* and *except for* as prepositions to mean ‘not
> including’ or ‘excluding’. They are followed by a noun or noun phrase
> or a wh-clause. Both *except* and *except for* are correct after a
> noun:
> 
> I like all fruit except (for) oranges. (excluding oranges)
> 
> Except for Louisa, who’s away in Berlin this weekend, we’ll all be at
> the party.
> 
> She likes going to most sports events, except cricket matches.

This shows the choice of 'Except for' to start a sentence-initial prepositional phrase, but does not go so far as to state that the choice of the simple preposition is incorrect.

The nearest (but really reversed) [question](http://english.stackexchange.com/questions/63155/except-for-vs-other-than) I can find on ELU is essentially 

> Is "Are there any vegetables except for asparagus?" correct?

to which Peter Shor provides the tantalysing answer (with which I largely agree):

> I think what's wrong is the "for". [I'd say 'very iffy' in all but some unusual contexts]
> 
> *Are there any vegetables except asparagus?*
> 
> The grammar of when to use "except for" and when to use "except" is
> governed by [a] quite complex set of rules (often, you can use either).
> There probably is a correct and complete description of how this works
> somewhere on the internet, but I haven't found it, so I can't tell you
> why you should use "except" here; but it just feels right.

Can authorities be found giving this *correct and complete description of the complex set of rules governing when to use "except for" and when to use "except"* , on the internet or elsewhere?