 With the demolition of the workhouse , however , Barry was able to build the Gallery 's first sequence of grand architectural spaces , from 1872 to 1876 . Built to a polychrome Neo @-@ Renaissance design , the Barry Rooms were arranged on a Greek cross @-@ plan around a huge central octagon . Though it compensated for the underwhelming architecture of the Wilkins building , Barry 's new wing was disliked by Gallery staff , who considered its monumental aspect to be in conflict with its function as exhibition space . Also , the decorative programme of the rooms did not take their intended contents into account ; the ceiling of the 15th- and 16th @-@ century Italian gallery , for instance , was inscribed with the names of British artists of the 19th century . But despite these failures , the Barry Rooms provided the Gallery with a strong axial <unk> . This was to be followed by all subsequent additions to the Gallery for a century , resulting in a building of clear symmetry . 
