oooh, I just checked our contract and it says 238 days including Christmas... hopefully it might be earlier then if they are speedy and the weather stays clear!!! yay!! (we are in zone 1)... wow, wonder why takes longer closer to the city?
My understanding is that Zone 4 has extra time added (normally around 2 months) is due to the fact that the houses are more isolated and further away than the housing estates. In housing estates the tradies can go from one house to the next. In Zone 4, generally knockdown rebuilds or just new builds so a little more work to line up the tradies. That is purely my rationale!