The single most characteristic element of Victorian and Edwardian residential architecture is the veranda, roofed with sheets of corrugated iron supported by posts and balustrades of timber or cast-iron, and floors of encaustic tiles. Many houses also had French doors opening on to the veranda, and the most important rooms were adorned with bay windows to provide an intimate linkage with the garden. Individual roof shapes were sometimes chosen to articulate particular interior functions, which, by exception, were distinguished by a look-out balcony or belvedere surmounting the apex.