OK here's my analysis, but I warn you, I am VERY picky about grammar and spelling
(I just suppress that on here otherwise I'd get hated out
)
Sentence 1 needs commas and an extra word, like so:
The building that belonged to THE Naval Intelligence Services was, for lack of other words, simply dull.
Sentence 2: "...crying for THE attention of a cleaning team"
Hmm, this is going to take longer than I expected.... oh well I can't be bothered now, so just some general comments:
Don't use the same word twice in the same sentence if you can help it. E.g.
"Dust that collected for decades in several places reached height of several centimeters."
you've used "several" twice, it sounds better if you select a synonym for the second occurrence. Anyway, the sentence sounds better as:
"Dust that had been collecting for decades in various places had reached heights of several centimeters."
Break it up into more paragraphs. Every new subject, start a new paragraph. Eg. you could start a new paragraph at "Other problems..."
There are many places where the choice of words shows that english is not your first language, and I or other people here can help you out with that. Generally it's very good for someone with English not as their first language [img]smile.gif[/img]