Water Harvesting and the Code for Sustainable Homes
Planning a new home or building a new house?
Have you heard about the Code for Sustainable Homes?
The Code for Sustainable Homes (the code) was introduced in 2007 as a national standard to be used in designing and building new homes. As the name suggests the idea is to encourage continuous sustainability in homes that are built and the code is best described as a means of assessing the environmental performance of a new home and then rating the home accordingly.
So, if you’re planning or building a new home or dwelling you need to be aware of this code because where building regulations apply you have to comply with the code. If you require a more technical discussion of the code and how it applies across all features of house building then we recommend you visit the Communities and Government website by clicking here.
We don’t propose to get into the “nitty-gritty” of the code here but we’re addressing this because part of the code has to do with water and how we use it – something that UK Septic Tanks has a lot of experience with - helping customers make better use of non-potable (non-drinking) water by harvesting rainwater and using garden irrigation systems. In order to achieve 5 credits in the code for what the code calls “Wat 1” (which is mandatory for Level 5 and above), then rainwater (or grey water) recycling will be required in practice.
Even for lower code levels, a rainwater recycling system used for flushing WCs etc can be specified in order to allow higher flow rates on taps etc, which might otherwise have to be reduced in order to satisfy the code and so this can be a means of balancing your preferences against increased capital cost and maintenance requirements of the code.
We all understand that water is a big environmental issue – every week we hear of drought, reservoirs and rivers at low levels and yes, the inevitable hose pipe bans. So in a nutshell the aim of the code when it comes to water is to reduce the consumption of potable mains water in the home, and of course water recycling systems are a great way to achieve this.
The idea of the code is to assess the environmental impact of any new dwelling against a performance target and then award one or more credits, leading to a code level being determined as part of your planning permission.
Performance targets set by the code don’t equate to minimum building regulation standards – they are more demanding but represent good practice in that they are considered to be feasible and deliverable by the building industry.
To give you an example of how the code levels work when it comes to water, below are the mandatory maximum standards in indoor water consumption, based on the code level that your planning permission will stipulate:
Code Level Maximum Indoor Water Consumption in Litres per Person per Day
Level 1 120
Level 2 120
Level 3 105
Level 4 105
Level 5 80
Level 6 80
Rainwater recycling as described in the code refers to collection and storage of rain from hard outdoor surfaces e.g. roofs etc which can then be used rather than potable water for example in WCs and/or applications such as washing machines etc. Rainwater can also be used of course for garden irrigation and even large water-consuming applications such as hot tubs or swimming pools.
The code specifies that the rainwater collector must meet the following criteria:
• No open access at the top of the collector (child-proof lid permitted).
• Provision of a tap or other means for drawing off water.
• Connection to the rainwater downpipes with an automatic overflow into the
conventional rainwater drainage system.
• A means of detaching the rainwater downpipe and access provision to enable
the interior to be cleaned.
• Where the collection system is to be sited outside, and not buried, it must be
stable and adequately supported; the material used for the container shall be
durable and opaque to sunlight.
• Where the system is part of a rainwater collection system providing internal
water, water for external use may be provided in a separate tank to water
required for internal use. This could be an overflow pipe leading from the main
tank to a correctly specified water butt for external water use.
The code also stipulates storage volume requirements and this is based on whether the home has a garden or patio/terrace:
• Terraces and patios – 100 litres minimum.
• 1 – 2 bedroom home with private garden – 150 litres minimum.
• 3+ bedroom home with private garden – 200 litres minimum.
The code allows for the above volume requirements to be halved if there is no planting provided and
the whole of the external space is covered by a hard surface. Where a house has front and rear garden the rainwater collector is only required in the main (larger) garden but must meet the capacity requirements above.
For more information about rainwater harvesting systems and garden irrigation systems please visit the relevant pages of this website and if you need some advice we would be happy to discuss your requirements – feel free to call us on 01296 326111.