Ip Flat minimum size for tax reasons SA

I know I read it somewhere but not sure where, is there a minimum size you need to have for tax purposes when buying a flat or apartment? If someone knows specific to SA would be good, thanks in advance.
You may be getting confused with the 50m[sup]2[/sup] limit the banks tend to frown on for getting finance. In other words, try and go > 50m[sup]2[/sup] to minimise any finance headaches.