Complex sentence: The building facade, designed and installed by French firm Dragages in 1997 had been checked in July last year and was certified safe by Dragages and its appointed building consultant Meinhardt (ST).
Split into simpler sentences: The building facade was designed and installed by French firm Dragages in 1997. It had been checked in July last year and was certified safe by Dragages and its appointed building consultant Meinhardt (ST).