The most common and most likely answer to this crossword clue is the 8 letter word FREEBIES
I've seen this crossword clue in The Guardian
F
R
E
E
B
I
E
S
Buddy explains!
The straight part
We know that "items on the house" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case items on the house = freebies.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 FREEBIES mean?
FREEBIES noun- Something which is free; a giveaway or handout.