Construction has begun on a distinctive 18-storey office tower on Sydney’s main street, designed by Grimshaw and Crone Partners to complement the area as it transforms into a pedestrianised boulevard.

In announcing the commencement, the owners Charter Hall released new renders of the building as projected to appear in the future precinct, with light rail running past.

The design responds to the site geometry with a curved facade giving the building a three-dimensional form that changes substantially when viewed from different angles.

The building design features five levels of cascading rooftop terraces with floor to ceiling windows.

It is targeting a 5-star Green Star As Built rating and a 5-star NABERS Energy rating upon completion in mid-2016. Plans include high performance glazing, rainwater harvesting and recycling as well as energy use monitoring.

Design architects Grimshaw and executive architects Crone Partners were also tasked with helping to reinvent the historic precinct in which the building sits. This precinct will be subject to major urban renewal and makeover in the coming years, with plans to pedestrianise George Street and introduce light rail.

Marking the commencement of construction of the office and retail building, Sydney Mayor Clover Moore said the building, sited opposite Martin Place, would help redefine George Street and return it to its status as the city’s main promenade. As well as reflecting the city’s 2030 vision.

 “333 George Street epitomises so much of what our 2030 work was about: quality development through innovative design, mixed uses to create a diverse and appealing city centre and – last but definitely not least – sustainability,” she said.

Grimshaw partner Andrew Cortese said the design intention was to create an elegant and innovative building that would restore the quality of architecture in the area.

“It will be a visually captivating place to work, one that engages with its environment, extends the premier retail streetscape and sculpts a landmark piece of architecture,” he said.

“333 George Street provides its occupants with an unrivalled opportunity to experience an intimacy with George Street and Martin Place – the city, its energy and activities will animate the day-to-day life of the building.”

The building design is described by the development team as having finely detailed crystalline facade in unique form sculptured from the arrays of sunlight and features curved corners that open up and tilt back as the building rises. It is intended to give 333 George Street a unique three dimensional form that will transform subtlety from varying aspects.

“Its transparency showcases its retail and workspaces while maintaining the highest environmental performance, daylight and views to the city,” a statement reads.

“Stepped landscaped terraces bring verdant green into the city centre. Taking best advantage of natural light, they offer integrated outdoor and indoor workspaces and increase the relationship of the office space with the street and surrounding architecture.

“This design creates a sense of community, interacting and engaging intimately with its environment and providing a sense of openness that goes beyond just its architecture and into the heart of the city.

“To maximise the site footprint and minimise unused space, 333 George Street’s flexible floorplates permit interconnecting voids to promote a vertically connected office environment to increase collaboration and communication for its occupants.

“At street level, the building presents premier frontage for retail that is both contemporary but fits within and extends the character of the heritage precinct. With 2,100sqm of prime retail space designed to activate the streetscape, it features full height transparent glazing over three levels complemented by elegant fluted sandstone columns.”