Two Building Maintenance Units were the fastest and easiest way to clean all the external facades. To maintain internal courtyards, 20 sections of SafeAccess monorail have been installed for the suspension of the RopeClimber. The hoist does not require a big storage area and is powered by battery. It is easy to transport between the courtyards and it can access remote facade areas. Engineering calculations for both systems have been thoroughly evaluated and approved by SIRVE Institute - Seismic Protection Technologies. The BMUs have been designed and produced by FBA Gomyl.