Heralding British taking on US city planning policy? (9)
I believe the answer is:
'heralding' is the definition.
'british taking on us city planning policy?' is the wordplay.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'taking on' means one lot of letters go next to another.
'us city' becomes 'la'.
'planning policy?' becomes 'zoning'.