The most common and most likely answer to this crossword clue is the 9 letter word DORMITORY
D
O
R
M
I
T
O
R
Y
More clues leading to the result DORMITORY
- Dirty room disturbed people sleeping here?
- Trim wood off, removing width by railway — it’s for sleepers
- Hall of residence staff redirected Mick, half-cut on right wing
- Awfully dirty room in building
- Dirty room could well be turned into one for sleeping
- Roy, do trim up the sleeping room
- Concealed around Swiss city, had some food and slept a lot?
Buddy explains!

The straight part
We know that "building" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case building = dormitory.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DORMITORY mean?
DORMITORY noun- A room containing a number of beds (and often some other furniture and/or utilities) for sleeping, often applied to student and backpacker accommodation of this kind.
- A building or part of a building which houses students, soldiers, monks etc. who sleep there and use communal further facilities.
- A dormitory town.