The soaring hall, with its impressive 'Waterloo Staircase', is the heart of Carrick Hill.  Assembled from two separate staircase from Beaudesert, the staircase was long thought to be from the reign of James I; however, the main elements are probably from the early years of the reign of George V.  Around 1815, the Marquess of Anglesey replaced the original Jacobean staircase with one of cast iron and oak with broad treads and shallow risers.  This made it easier for him, with his wooden leg, to negotiate the stairs.  Second-in-command to Wellington, the Marquess' leg had been amputated after the Battle of Waterloo and famously buried with full military honours.

That staircase was in turn destroyed by a massive fire at Beaudesert in 1909.  It was replaced in 1912, probably in old oak, with the design copied from examples in at least four other English houses.  This was an attempt to replicate the Jacobean period, which was experiencing a revival in England.  Fittingly, in 1939, the staircase became part of Adelaide's Jacobean revival.