[Verb て form~, い adj. (ーくて)~, Noun/な Adj.+で~] This sentence construction allows the speaker to ask for, or grant permission to do. This pattern is usually used to recieve premission from superiors, but not to grant permission to superiors.
~は だめです/いけません。
[Verb て form~, い adj. (ーくて)~, Noun/な Adj.+で~] This pattern expresses prohibition and is used by superiors to inferiors. だめです is percieved as a stronger expression than いけません.