The hospital said the project required it to dismantle the arch – which did not have any historical grading – to make room for the new facilities, including an escalator and lift, but it would store the original materials and reassemble the arch later.

Two Hong Kong conservation experts have backed a proposal by heritage arts venue Tai Kwun in Central to retain only the facades of a partially collapsed historic block, saying structural safety must be the top priority.

Their comments on the plan on Sunday came after it was revealed that Block 4 of Tai Kwun, the former Central Police Station compound, had showed “signs of continuing deterioration” and parts were “unsafe to retain” after its partial collapse eight years ago.

Most members of the Antiquities Advisory Board also backed a proposal by the club to build a canopy to protect the parts of the block that survived a partial collapse in 2016.

At the centre of the discussion on Thursday was the three-storey Block 4, one of 16 historic buildings in the compound, now used as a contemporary arts venue and also known as Tai Kwun, in Central.

The block formerly housed the married inspectors’ quarters.

After years of assessment and investigation, the club, which oversees the restoration of Tai Kwun, removed unsafe structures including roof coverings and components between February and June.