The most common and most likely answer to this crossword clue is the 6 letter word GOTHIC
I've seen this crossword clue in The Times
G
O
T
H
I
C
More clues leading to the result GOTHIC
- Understood this Latin building style
- Face family, cold, having received welcome earlier
- Understood one in church recalled architectural style
- Old time greeting in good Conservative style from way back
- Become endlessly stupid, and like horror stories
- Baffled by drunken noise of moody teenager
- Try substantial detailed typeface
- Leave mostly stupid, horrific
- Like many cathedrals, become almost intimate
- Style attained height in churches, primarily
Buddy explains!

The straight part
We know that "building style" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case building style = gothic.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 GOTHIC mean?
GOTHIC adjective- Of or relating to the Goths or their language.
- Barbarous, rude, unpolished, belonging to the “Dark Ages”, medieval as opposed to classical.
- Of or relating to the architectural style favored in Western Europe in the 12th to 16th centuries, with high-pointed arches, clustered columns, etc.
- Of or relating to the style of fictional writing associated with the Gothic revival, emphasizing violent or macabre events in a mysterious, desolate setting.
- Of the name of type formerly used to print, at last, German, also known as black letter.
- Of a sans serif typeface using straight, even-width lines, also known as grotesque.
- Of or relating to the goth subculture, music or lifestyle.