You can now upgrade your personal building! To do so, open your shack.
Please note that at present, the only effect of this is that your midnight tax will be reduced from 5% by 1% per upgrade, to a minimum of 1%.
The next task is Clans. This will be released as a full expansion and will include:
Personal Building 'Slots' for extra upgrades,
A final Personal Building level, which will give Tax Exemption at midnight,
The second City,
This will be a big project, but I will keep you updated throughout