subdiv new blocks smaller than regular allotment size

Hi there,

Does anyone have experience of successul subdiv projects where the new blocks are slightly smaller than the council regular allotment size.  How much variance is possible and what councils were you dealing with? 

I have an opportunity where the each of the subdiv blocks would be 20sqm smaller than required i.e. 540sqm instead of 580sqm in Ryde council NSW.  Although I'm generally interested in peoples experience so I know whether I can filter these opportunities out.

Cheers