these modern macmansions got almost 2 downpipes per side plus 2 for
the garage so very very ahrd to get good catchment going for you, we
have managed to without huge expense reposition the flow of the
guttering block off one downpipe, put a dam into one section of
guttering to force the water to go our way, and get 2 downpipes into
the tank.


Having many downpipes is good as it means that your gutters will not
overflow in a heavy downpour. This may save water getting into the house or
damaging gardens.

but it isn't realy enough but nought we can do new homes are not built
for conserving anything, and for some there is barely room to walk
around the house outside, so owners forced to buy very small and very
inadequate tanks.


The many downpipes is good for conserving water too as it also means you
will harvest all the water in a downpour BUT the system has to be designed
for them to flow into your tanks. The space issue is also difficult but
remember that your tank does not have to be right next to the house as long
as the feed pipes still run downhill to the tank inlet. Long runs of
plastic drain up in the air may be unsightly but you can always put them on
a trellis and grow something over the whole lot.

we got 22mm of rain alst night and with an eco designed home we would
have had in excess of twice the amount of water we eventually got
saved.


Yes designing with water saving in mind makes a big difference.

David