Stevens Crescent is Andy's own house in Totterdown, Bristol. It is in the middle of a terrace with only a small back garden so the water reservoir was made tall and thin to minimise floor space. The building has a valley roof so this allowed the header tank to be placed externally within the valley (which also meant along a load-bearing masonry wall).
Reservoir
A small garden restricted the amount of storage that could be placed on the floor. To address this, three steel water barrels were welded end-to-end into a single, tall reservoir with a volume of 800 Litres.
A float was added to the reservoir with a line over the edge attached to a handle. This was so that when the water level fell, the float would fall, and pull up the handle and show the current level.
Pump
A submersible whale pump was lowered into the reservoir and this pumps the water up to the header tanks. Float valves were used on the header tank and the reservoir to stop the pump. One to stop pumping when the header tank is full, and the second to stop when the reservoir runs low. The pump mechanism and associated switches run on 12volts via a transformer that plugs into a standard wall socket.
Header
Two header tanks were located externally, within the roof valley. This meant that any overflow could simply run onto the roof and back into the reservoir.
Outputs
The toilet within the bathroom was the first item to be connected.
Next was a hand washing tap in the bathroom, and one over the kitchen sink for use when rinsing dishes or cleaning work.
Lastly, the cold water feed of the washing machine was connected to the rainwater system. When a new maching machine was purchased, this required only a cold feed (so further reduced the mains water being used) and also used less water for each cycle.