It was designed by George Allen Mansfield (original), William E. Kemp (1891 extension to north), Walter Liberty Vernon (1900 and 1902 addit and built from 1876 to 1877 by W Jago.

[2] Prior to British colonisation in 1788, the eastern part of the north shore of Port Jackson (i.e. Terrey Hills, Duffys Forest, Narrabeen, Dee Why, Curl Curl, Freshwater, Manly, Middle Cove, Lane Cove, North Sydney and Chatswood) was originally inhabited by the Gai-mariagal people.

The land on which the former North Sydney Technical High School stands was occupied by the Gammeray people, recently referred to as Cammeraygal or Cammeraigal.

By 1830, records show that, apart from a group camping in the government boatsheds west of Circular Quay, few people identified as Aboriginal were living in Sydney.

The plans included construction of a new Gothic Revival stone building to accommodate at least 100 children, an adjoining small religious room, and the erection of a new teachers' residence with detached kitchen.

The gabled roof featured ornamental bands of hexagonal shaped slates, carved finials, and detailed barge boards.

The building boasted a finely detailed bell tower, which was one of the earliest and most prominent landmarks of the lower North Shore visible from the city.

In 1890 the school was connected with gas, classrooms were completed for £896, and technical classes commenced in shorthand, bookkeeping, drawing and building construction.

In addition to these changes, new fencing was erected, all wood and ironwork was repainted, and the flagging on the south side beneath the verandah was replaced with new stone.

In 1980 Lendlease won a tender to lease the site, but failed to win approval from planning authorities to build a $100 million complex.

[1][3]: 6–9, 16–17, 19 The most challenging aspect of the development was the excavation of 145,000 square metres (1,560,000 sq ft) of sandstone around the footing of the former school building.

[1][3]: 6–9, 16–17, 19, 20 In November 1991 the project ran into financial difficulties and Industrial Equity liquidated its $500 million investment into the plaza and changed the contractor to Multiplex.

In June 1992 Optus agreed to lease the tower and paid for naming and signage rights to the building, giving it a dominant position in the North Sydney skyline.

[1][3]: 6–9, 16–17, 19, 20, 22 The Kemp-designed two storey brick school buildings facing Miller Street were demolished as part of the tower redevelopment.

A new school-house was built during 1877 in the Gothic Revival style at Blue Street, North Sydney by the New South Wales Council for Education.

Often referred to colloquially as “Greeny’s” for Nimrod Greenwood, its longest-serving head-master (1884-1914), the school grew, spawned others, was modified and shaped; its curriculum specialities and name, changing to reflect the needs of a rapidly expanding north shore community; its educational philosophy inspiring achievement over generations.

[8][9] The Old Lions holds a members' dinner and a teachers' lunch each year, and provides a monetary award to Killara High School students for Excellence in Technology and Applied Studies.

As at 29 September 2008, the Greenwood Hotel is a rare and unique example of Gothic and Romanesque Revival styles and remains substantially intact from 1908.

The fact that the school was used continuously for educational purposes from 1877 to 1969 is of high significance and has created a strong cultural meaning to people in the area.

The sandstone structure is now surrounded by open landscaping and urban development elements and the nearby towers are set away from the Greenwood Hotel.

This space has become an important urban precinct for retailers, office workers and locals, and is well utilised as a pedestrian thoroughfare and a place to meet and relax.

The two remaining Moreton Bay Fig trees retain the setting of the Greenwood Hotel and the landmark qualities of the area.

[1][3] North Sydney Technical High School was listed on the New South Wales State Heritage Register on 2 April 1999.