[Kelvin]

The increase in cost related to height is not a linear adjustment. The complexity and cycle times increase exponentially as height increases and therefore so do costs.

As an example, based on constructed costs for highrises around the world (but mostly US projects), my best-fit model is:

Cost = $4,000 * Z^2, where Z is the building height in metres and "Cost" is in constant 2001 US Dollars.

In your example, Z=220m, so Cost = $193.6 Million. That is a "base" cost for a generic highrise of this height anywhere in the world. There are an endless number of other contributing variables (currency exchange, taxes, land prices, remotness, local labour supply, etc.) that will obviously adjust the final price for your particular situation. I would suggest a contingency fund of 50% to 100% at this stage, until better definition is aquired.

Also - construction cost should be based on GFA, not NFA. Your 35m x 35m footprint has 1225 sq.m, and your total GFA is 24 500 sq.m. The basic construction cost is thus approx. $8,100/m^2 (no contingency).