The triangular plan is efficient (that's why it was used in Toronto's CN Tower, until recently the world's tallest freestanding structure)- "the vertical city is a powerful triumvirate of three ‘arms’ that meet at a central green spine running the full height of the tower. Wider at the base and tapering towards the top, the pyramidal form is elegant and slender in profile, and benefits from a highly efficient composition to achieve the maximum stability with the minimum structure, as well as the most effective distribution of space."
It is a mixed use building with both offices and residential; while offices generally create excess heat and need air conditioning even in winter, residential does not. They have developed an "energy cycle" system using water and heat pumps to redistribute the heat to where it is needed from where it is not.
"Mixed-use presents a strong case for energy balance, dependent on the residential components using energy at different times to office and retail.
By harnessing the heat created by the offices in winter and the cooling properties of the ground in summer, the energy cycle is a hot water circuit that runs through the building, distributing the energy to regulate the temperature and heat water throughout the day and the year."