The War Office has declared that she would like an irrigation system installed. I have installed one before but to be honest I didn't like the control unit part of it as it was far from intuitive (contrary to the ad!):
http://www.garden-irrigation.co.uk/acces3.htm top of the page.
Does anyone have any recommendations please. It will need probably 5 circuits: 3 lawn & 1 border in rear garden, one border / hanging basket drip at the front, controls will be in garage, I guess the solenoids would as well, but they could be buried I guess.

Oh you wouldn't believe how much my back is looking forward to digging the trenches to bury this pipework!

We are metered, but the wife has mentioned trying to use water from a rainwater butt. She wants the system primarily so that when we go away, we don't come back to a dry scorched lawn & dead flowerbeds!
I've tried to convince her it is more trouble than it's worth but we had one before & she wants one again!

I am fully aware of this, I just wanted recommendations for irrigation systems.

Never used them but google suggests these people have a basic gravity fed electrically controlled irrigation system...

http://www.watermate.co.uk/Rainwater-Irrigation-c1/

Gravity? It's going to be mains pressure. It will need 5 or 6 circuits so a simple timer will not be enough. I think I am asking in the wrong place actually but don't know where I should ask.

That's a thread about pumps ? There will be no pump.

What make / model water timer was that, I'll avoid it!

That's not a sprinkler timer with a minimum of 5 circuits is it, so how do you control 5 seperate circuits with an immersion heater timer?
I don't think anyone understands the question!