 The facade on the Piccadilly side is roughly 231 feet ( 70 m ) , 115 feet ( 35 m ) on the Arlington Street side , and 87 feet ( 27 m ) on the Green Park side . The irregularity of the site presented initial problems for the builders . Davis dealt with this by " brilliant perspective effects " according to Binney , using curving walls to " cleverly conceal the rapidly diminishing space at the back of the hotel " . The purpose of the arcaded front was to provide more space for the bedrooms above . Expensive Norwegian granite is the material on ground floor , with Portland stone above it . 
