Building Up is Heavy on the Earth
The taller the building, the more of the earth’s resources are needed to support it. As an example ‘On average a 4 to 5 floor apartment building in The Netherlands comes close to 1 ton per m2 living area’. Compare this to ‘the Empire State building [which] is around 1.7 tonnes, or Taipei 101, which consumes 1.8 tonnes’. The negative impact on the environment from building up can be reduced by using renewable materials: wood for instance. So ask yourself: ‘How tall is a sustainable building?’
In my opinion the tipping point for adding weight is between 3 and 5 storeys. New Zealand’s building code NZS 3604 can be used for timber-framed buildings with one, two or certain configurations of three storeys. In Hamilton, concentrations of two and three storey residential buildings can already give a population density of over 4,000 people per square km, within the existing height control planes (DP 4.4.5 - Height in Relation to Boundary). Question: what is good density?
The higher you build, the more weight you need at ground level and every subsequent level to manage movement from wind pressures. Add extra elevators, which increase the lobby area and reduce the floor space for which the building is built, and you increase the per square metre cost of usable space. The outcome is less affordable accommodation and a higher carbon footprint.