Complex sentence: Until the company went into liquidation on 15 January 2018, it was being built by Carillion who were also to provide hard facilities management and life-cycle maintenance services.
Split into simpler sentences: Until the company went into liquidation in January 2018, it was being built by Carillion. Until January 2018, it was being built by Carillion who were also to provide hard facilities management and life-cycle maintenance services.