Woodside House, above Quarry Bay [1924- ]
The book 'Sustainable development in Hong Kong' gives a brief account of the building's history:
Standing on a hill just outside the border of Tai Tam Country Park, the redbrick, two-storey house was built around 1917 ((actually built in the early 1920s, see comments below)) by the trading house Butterfield and Swire for the families of two middle managers. The company operated the Taikoo sugar refinery and dockyard, which were the main industries around Quarry Bay at that time.
The chapter continues with a description of how the government planned to redevelop (ie demolish) the building in the late 1990's, but eventually backed down after public opposition.
Phil also has a longer description of the building's history, and a surprising discovery in its library. [See Phil's comment below for the updated link.]