The most common and most likely answer to this crossword clue is the 6 plus 3 letter word NISSEN HUT
I've seen this crossword clue in Financial Times
N
I
S
S
E
N
H
U
T
More clues leading to the result NISSEN HUT
- First of early NHS units built in military accommodation
- Military facility shuts, nine redeployed
- Sunshine transformed front of the military prefab
- Sunshine altered temperature in shelter
- Perhaps he is nuts storing nitrogen in military structure?
- Wrong over having to prevent access to space inside military housing unit
- Soldiers’ lodgings in Northern Ireland closed? About three-quarters
- Shelter from the sun, after tanning back in sun first
- Put up popular nurse in secure metal shelter
- Shelter for navy is closed with nurse on board
Buddy explains!

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.