Zone 5 "quantity" Guidelines?

Hi,

In permaculture design you sometimes come across "rule of thumb" guidelines about the quantities of certain design elements.

E.g.

5-15% Water

30-50% Trees

I know Zone 5 is mandatory, but has anyone got any feelings about how much is a reasonable amount?

Thanks in advance,

Pete.

In my opinion, zones 4+5 should be between 40-60%.
Zone 5 should ideally cover all borders, waterways and roads. This helps link zone 5 areas together, with all you permaculture neighbours (along borders) and interconnects the parts for wild life (waterways and roads).
When doing the design, I think it is easy to plan zone 0, 1 and then 5. So that you have a rough idea of where it goes. You can modify it later if the areas aren't working perfectly for you.

I think it's site dependent. For a very small lot it could be a an unused 5x5 spot in a corner somewhere.