The City Center is a Public Building that fulfills the Need for Community to the Ecos, the Tycoons and Techs. It has a radius that allows for the construction of Residential (Public) and Special buildings of all three factions. If a Residence is not within the radius of the City Center and/or is not connected to it somehow, the inhabitants of the Residence will abandon it.
Although the Tech City Center is smaller in size, it also has a decreased influence area, making it inadvisable for use as a replacement of the Eco or Tycoon city centers in highly-developed areas. Additionally, the Techs will generally give the player less tax revenue than its Ecos or Tycoon counterparts.
Clicking this building will display the City Center panel with useful data about the island it's located on, including power usage, ecology, and building information. This makes it useful even on islands without any population, such as those dedicated to industrial production. Coupled with its low maintainence cost, and the fact that it can be placed independently of a supply depot, this gives it a dual use as a sort of 'monitoring station' that can be invaluable in places that may have upwards of 30 structures or more.
The red Ascension Rights toggle in upper right corner controls automatic or manual upgrading of buildings from level 1 through level 4. Set to Release Ascension Rights (Default setting), buildings will upgrade to the next level automatically when all conditions are met (upgrade materials available, Taxation on Euphoric and all Needs in the green). Set to Ascension Rights Denied, buildings will not upgrade on their own, rather a green arrow will be shown over every eligible Residence. These can then be upgraded individually on their own info panels. Please note that all four levels of Residences can be denied Ascension Rights individually, rather than using the island-wide toggle of the City Center which affects the Ascension Rights of all four levels.
The first tab on your City Center display is the Population tab which lists detailed numbers about resident types and tax income in drop down menus. Whenever Ascension Rights are automatic, the dropdown menu of Population will list upgradable Residences by showing a small up-arrow next to the Residence type, as well as a small white number indicating the amount of buildings ready to be upgraded. Manually clicking these upgrades buildings faster than their natural rate of getting themselves upgraded.
The Ecology and Energy tabs list island-wide eco-balance and energy contribution, as well as further information on mouseover.