Complex sentence: In 2008 to 2009 the old showrooms were converted for retail and restaurant use but the original Octagon Chapel remained unfurnished and with no permanent tenant for some years and was used frequently for exhibitions, art shows, retail, catering, events and festivals.
Split into simpler sentences: In 2008 to 2009 the old showrooms were converted for retail and restaurant use but the original Octagon Chapel remains unfinished and with no permanent tenant. It is used frequently for exhibitions, art shows, retail, catering, events and festivals.