"broad balcony" is correct and usable in written English.
You can use it when you want to refer to a balcony that is wide and spacious. For example, "The apartment had a beautiful view of the city from its broad balcony."
Fifteen minutes later we were standing on the house's broad balcony gazing toward the turquoise ocean.
On this particular day in Beirut, the sun was shining on the broad balcony of Mr. Jabotian's atelier.
THE dancers of the Tanztheater Wuppertal were rehearsing in late August in Pina Bausch's favorite studio, a former movie theater with a broad balcony and a slim stage.
From the broad balcony, where in 1912 only clouds could interfere with the view, tall buildings now ring what has become a relatively puny perch.
Outside, a broad balcony overlooked two facing hills, with the ocher rooftops of the town's much smaller peasant houses and a few church spires filling the space between them.
Along the entire length of Maplewood, on both sides, five-story brick apartment complexes with broad balconies rose above new stores shaded by ornamental pear trees.
It still has high-ceilinged colonial barracks with broad balconies and a royal crest from 1937 in the stonework over the entrance.
Crater Lodge stands on the southern rim of this Unesco-listed wonder, with 32 stilted suites styled to resemble traditional Maasai mud huts (albeit with butler service, glass fronts and broad balconies for surveying the scenery).
Flats are reached by broad balconies, following its architects' theory that they would be "streets in the air", places where the lively street life of the cockney city would be replicated.
The building is surrounded by broad balconies that open up to the outside, and notable features include a staircase that leads down from the living room to the stream that is accessed by movable glass panes.
A blend of Queen Anne and colonial revival styles, it has a wraparound porch and broad upper balcony, as well as several turrets.
