There have been many guidance changes in recent times surrounding multi-residential developments and their usage profiles for energy.

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Today we discuss water consumption and the approach taken for St James Road which is served via a central water break tank and booster set. The longstanding and familiar British Standard BS 6700 was withdrawn in 2012 and replaced with BS EN 806 and BS 8558, however as it was so well cited, many designers still apply the practices from it, including the water demand amendment method.

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In reality, due to changes in people’s lifestyles and the introduction of flow limiters on sanitary ware, new developments use considerably less water. For example under the old BS 6700, St James Road would be assessed under a 15 minute peak period to use 5904 litres. Using the new BS EN 806 for the same period, the demand is amended to be 2439 litres. This gives a reduction in 59% of the predicted water consumption.
For St James Road and all modern day developments where floor area is at a premium, this allows us to greatly reduce plant footprint by way of a smaller tank. Additionally as a consequence the peak flows are reduced, resulting in smaller pipe sizes to carry the water which improves on installation costs and coordination.

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Lastly as generally considered the world leader in legionella control and prevention, the new guidance goes a long way in increasing water tank turnover and limiting standing water for new developments throughout the UK.