Want a simple rain water harvesting system with less moving parts and less potential maintenance issues? Architects need to design with this in mind.

The talk about probable future rising oil prices and the recent debate about water charges in Ireland might give reason for some to plan for long term sustainability issues; such as reducing energy use and water use.

But there is another reason to be interested in a simple pump free systems – there are less things which can go wrong and therefor less potential maintenance issues long term. If you are interested in this approach, Architects need to design their house buildings so that the collected rain water always runs downhill; by gravity

Zero pumping and zero electricity rain water harvesting systems should therefore be considered for your new home if this is the way you are thinking. When designing your new home here are a few rules for your architect that I would suggest.

Rule 1: For zero energy systems, indoor rainwater storage tanks need to be located on a level below the rain water leaf filter and above the toilet cisterns. Generally these tanks are fitted into purpose built cupboards inside the building in order to support the large weight of the water.

The tanks in their cupboards also need to be clustered and located near to the toilets as well as being near or next to the outside rainwater down pipes.

Rule 2: Cluster all of the upstairs toilets and wet rooms to be together and adjacent to each other. Do not locate these rooms to be separate from each other in far off corners of the house. Where possible keep all the toilets and the rainwater storage tanks that will be using and storing the gravity rain water in one section of the house.

Rule 3: Do not separate the rainwater down pipe, the rainwater storage tanks or the toilets from each other. Door openings, windows and corridors between any of these elements will frustrate the purpose of gravity based systems. If pumps for rainwater are to be avoided, make sure that none of these obstacles occur. Long horizontal rain water pipe runs on the outside or the inside wall of buildings are also not desirable.

Rule 4. Where possible, keep the ground floor toilets and the utility room below the upstairs toilets also. The clothes washing machine could use the rain water also.