General interesting information
The code for sustainable homes
A step-change in sustainable home building practice
As the Stern Review highlighted, there is now an overwhelming body
of scientific evidence showing that climate change is a serious and urgent
issue. In 2004, more than a quarter of the UK’s carbon dioxide emissions
–
a major cause of climate change – came from the energy we use to
heat,
light and run our homes. So it’s vital to ensure that homes are
built in a
way that minimises the use of energy and reduces these harmful emissions.
Construction and use of our homes has a range of other environmental impacts,
created for example through water use, waste generation and use of polluting
materials, which can be significantly reduced through the integration
of
higher sustainability performance standards within the design of a home.
More sustainable homes can also provide us with improved overall wellbeing
and quality of life.
The Code for Sustainable Homes has been introduced to drive a step-change
in sustainable home building practice. It is a standard for key elements
of
design and construction which affect the sustainability of a new home.
It will
become the single national standard for sustainable homes, used by home
designers and builders as a guide to development, and by home-buyers to
assist in their choice of home.
It will form the basis for future developments of the Building Regulations
in
relation to carbon emissions from, and energy use in homes, therefore
offering
greater regulatory certainty to developers. And in this era of environmental
awareness amongst consumers and increasing demand for a more sustainable
product, it will offer a tool for developers to differentiate themselves.
If we build the homes we need, then by 2050, as much as one-third of
the total housing stock will have been built between now and then. Current
house building plans therefore offer an important opportunity to build
high
standards of sustainability into the homes we will use in the future.
The
Code for Sustainable Homes will play a key role in enabling us to seize
this opportunity, and to build a future housing stock which both meets
our needs and protects the environment.
This booklet explains what the Code for Sustainable Homes is and how it
works. It also includes tables showing the criteria that assessors will
use to
measure achievement of sustainability performance under the Code.
Enhanced capital allowance scheme for commercial rainwater harvesting schemes
The Water Technology List (WTL), developed and
managed by Defra and HM Revenue and Customs, in
partnership with Envirowise, offers a real incentive for
industry to invest in technologies that use water sustainably,
making for a win-win situation both environmentally
and economically. The WTL enables businesses
to claim 100% first year capital allowances on
investments in technologies and products that encourage
sustainable water use. Businesses are now
able to write off the whole cost of their investment
against their taxable profits of the period during
which they make the investment.
One of 14 technology categories, rainwater harvesting
equipment was added to the list in August 2004 and
includes over 700 products in the sub-categories of:
• Rainwater filtration equipment
• Rainwater storage vessels
• Monitoring and control equipment
• Water level and consumption indicators
• Mains back up control unit
• Rainwater treatment equipment
• Ultraviolet disinfection unit
• Membrane filtration unit
This technology is applicable in all areas of water use
across industry and commerce. With increasing water
supply and discharge costs this new technology category
could offer the potential for businesses to make
significant savings.
Further information on the WTL can be found at
www.eca-water.gov.uk
Enhance Capital Allowances -
Association Advice to the Industry
The Enhanced Capital Allowance Scheme (ECA) has
been put in place by Government to encourage the
take-up of emerging industries such as rainwater harvesting;
through the scheme, businesses which pay
income or corporation tax can write off 100% cost on
an eligible investment against their taxable profits,
providing a reduction in their tax bill and thus improving
their cashflow
This incentive to invest in rainwater harvesting technology
is therefore potentially an important aid to
sales which UK-RHA members would wish to bring to
the notice of those who can potentially benefit from
the scheme. This Industry Advice Note is therefore
intended to help members promote the benefits of
the scheme and to suggest that when doing so they
are aware that:
• To be eligible for support under the scheme,
the product must first be Water Technology
Lists (WTL) approved
• Products in this context refers to components
of a systems, rather than whole systems
• Applications for approval are usually made by
either the component manufacturer, or supplier,
or system assembler
• Not all components in a system will necessarily
qualify; the qualification procedure has within
it certain checks and balances designed to prevent
abuse of the ECA Scheme which can lead
to apparent anomalies from the industry's per-
• Water Technology List & Enhanced Capital Allowance
spective; opportunities to make representations
about such anomalies arise during periodic
consultative reviews, but cannot otherwise
be remedied
• The claimant under the ECA Scheme must be
the project's commissioning client, who may
not be the Principal Contractor or Sub-
Contractor to whom the sale is made
• To facilitate the claim, if it is known that one is
to be made, members are advised to identify
on invoices the ECA-allowable goods
• Notwithstanding the above, different HMRC
• Tax Offices may make varying interpretations
when applying ECA rules, for which neither the
• Generally speaking, queries to Tax Offices
about the scheme should be limited to their
interpretation of its rules, rather than about
the eligibility of the product which is a WTLlisting
issue
What is BREEAM?
BREEAM is the world's foremost environmental assessment method and rating system for buildings, with 200,000 buildings with certified BREEAM assessment ratings and over a million registered for assessment since it was first launched in 1990.
BREEAM sets the standard for best practice in sustainable building design, construction and operation and has become one of the most comprehensive and widely recognised measures of a building's environmental performance.
A BREEAM assessment uses recognised measures of performance, which are set against established benchmarks, to evaluate a building’s specification, design, construction and use. The measures used represent a broad range of categories and criteria from energy to ecology. They include aspects related to energy and water use, the internal environment (health and well-being), pollution, transport, materials, waste, ecology and management processes.
A Certificated BREEAM assessment is delivered by a licensed organisation, using assessors trained under a UKAS accredited competent person scheme, at various stages in a buildings life cycle. This provides clients, developers, designers and others with:
market recognition for low environmental impact buildings,
confidence that tried and tested environmental practice is incorporated
in the building,
inspiration to find innovative solutions that minimise the environmental
impact,
a benchmark that is higher than regulation,
a system to help reduce running costs, improve working and living environments,
a standard that demonstrates progress towards corporate and organisational
environmental objectives.
What does BREEAM do?
BREEAM addresses wide-ranging environmental and sustainability issues and enables developers, designers and building managers to demonstrate the environmental credentials of their buildings to clients, planners and other initial parties, BREEAM:
uses a straightforward scoring system that is transparent, flexible,
easy to understand and supported by evidence-based science and research,
has a positive influence on the design, construction and management of
buildings,
defines and maintains a robust technical standard with rigorous quality
assurance and certification. ?
Who uses BREEAM?
Clients, planners development agencies, funders and developers use BREEAM to specify the sustainability performance of their buildings in a way that is quick, comprehensive, highly visible in the marketplace and provides a level playing field.
Property agents use it to promote the environmental credentials and benefits of a building to potential purchasers and tenants.
Design teams use it as a method to improve the performance of their buildings and their own experience and knowledge of environmental aspects of sustainability.
Managers use it to reduce running costs, measure and improve the performance of buildings, empower staff, develop action plans and monitor and report performance at both the single building and portfolio level.
What is Rainwater Harvesting?
Rainwater harvesting is a way of saving the rainwater which would normally
flow off a roof and down the drain, and using it as piped water to flush
toilets and for the garden watering, yard washdown, vehicle and car washing,
and even for your washing machine, instead of using expensive treated
drinking (potable) water.
Are there planning regulations associated with rainwater Harvesting?
They are not required directly by Building Regulations, although they
may be linked with the Planning Permission for the storm-water management
of the site. Building Regulations do cover the installation itself, tank
siting & pipe runs etc.
Will a system affect my homes eco rating?
Yes, rainwater harvesting is an important ER criterion. The EcoHomes rating
system addresses all aspects of reducing potable water demand in a dwelling.
Installing a rainwater harvesting system adds to the credit rating for
water use.
What types of rainwater harvesting systems are there?
Un pressurised: rainwater is gravity fed from a header tank, usually in
the loft to the point of use.
Pressurised: The rainwater is pumped directly from the above or under-ground
tank to the required point of supply. i.e. toilet, outside tap etc.
Is there a danger of legionella?
No, the system does not provide the conditions necessary for the cultivation
of Legionella. With the water stored underground it is dark cool and is
kept well oxygenated. Legionella cannot cultivate in these conditions.
How is the system maintained?
As a general rule filters should be thoroughly cleaned once a year and
we recommend a full 'flushing' of the system every three years. A treatment
with an anti-algicide such as sprayguard is also recommended. A correctly
designed harvesting system overflows on a regular basis to remove floating
matter and the pumps are very reliable. Maintenance should only be carried
out by qualified or experiences personnel. Combined harvesters have their
own teams available year round to keep systems working efficiently.
What kind of pumps are used in the systems?
Pumps can be housed either internally in the tank or mounted within a
control unit fitted in a garage, plant room etc. Pumps should have run
dry protection and should have a pressure switch fitted to stop hunting.
Internal tank pumps need to be constantly submersed in water to prevent
damage from the air, from debris or sediment that may be sucked in. An
external pump or control unit should have an audible alarm to identify
faults in the system, when fresh water is being used etc.
How much does it cost to run a rainwater harvesting pump?
It typically takes 1.5- 2.0 kWh to pump 1 cubic meter of water (1000 litres).
For a typical house using rainwater for WCs, washing machine and the garden,
pumping costs are between 5-10p per week
Do I need to have a water meter?
This is not generally necessary; however the absence of one will reduce
you seeing the benefits of harvesting rainwater immediately.
What does the British Standard BS8515:2009 cover?
BS8515 covers the design, installation, water quality, risk management
and maintenance of rainwater harvesting systems. This applies to both
new and retrofit properties.
What is the payback period?
This figure will depend upon the rainwater that you collect and the use.
A typical domestic client will see a payback between 5-10 years. Commercial
clients should be able to reduce this figure to 2-5 years.
Is it only for new builds?
No systems can easily be retro-fitted.
What design aspects are to be considered to comply with BS8515?
Designs should be provided by an industry expert, amount and intensity
of rainfall, type of intended applications both now and in the future
will be considered. Tank size will depend upon ground conditions and surface
water. All these as well as filtration requirements, end use by clients,
site restrictions and other factors not necessarily covered by BS8515
will be considered when designing a system.
What happens when there is no rain?
In the absence of rain, correctly designed systems will have a 'mains
top up' facility ( not always required for garden systems ). This will
fill the tank with the minimum required amount of water to keep it functioning
until the rain returns or a small holding tank on the management unit..
Is rainwater harvesting suitable for work as well as at home?
Yes, in schools, hospitals, offices, commercial premises, rainwater can
typically be used for toilets, vehicle washing, yard wash down and watering
plant pots/gardens.
Can it be used when there is a hosepipe ban?
It is possible to use a hosepipe connected to a rainwater tank, provided
that the tank is not connected to a mains water supply. Many people are
doing this already by using a water butt.
Is it only for houses?
No, bungalows and commercial premises are also very suitable, the only
limitation is the area of the roof to capture rain, in fact commercial
and industrial buildings can make the largest savings.
Where is it installed?
The tank should be buried under a car or vehicle park, landscaped area,
garden, patio or drive, with space left for the round access cover. Most
systems are designed so that they can accept cars driving over them if
suitably installed. Or an above ground system can be installed next to
the house or property.
Are there any grants available?
Not for domestic installations yet, although several organisations are
petitioning the government for assistance. For commercial installations,
there is a tax relief scheme (ECA) for suitable approved equipment on
the Water Technology List.
How clean is the water?
The rainwater is filtered as it enters the storage tank, to remove particles
and other matter. It is kept in the dark and kept oxygenated to discourage
algal growth, and properly designed systems are designed with calming
inlets, which ensure that any sediment at the bottom of the tank does
not get stirred up. The water is not drinking water fit for humans.
How do you stop debris from entering the system?
A filter is fitted along with a ‘calming inlet’. The filter
has to meet strict criteria covering its weather resistancy, accessibility
and efficiency.
How much rainwater does a system collect?
This depends on the area and angle of your roof, and your rainfall. Averages
of 100,000 litres per household are commonly quoted, much more for large
roofed commercial buildings.
Is the tank covered by BS8515:2009?
Yes, all tanks are covered. They need to be water tight, discourage microbial
growth, avoid stagnation and thereby legionella .Tanks need to be suitably
load bearing and need to resist floatation.
Pipes to and from the tank need to be clearly marked, rainwater pipes
can be green or black (not blue) .Special marker tape can be purchased
to show piping on a scan.
Does the tank need an overflow?
Yes, the overflow needs to be the same diameter or even larger than the
inlet, it must also be fitted with back flow prevention. Overflows are
important as a tank should be the correct size so as to overflow at least
twice a year to ‘flush the system’.
How much would this save on water bills?
Depending on your normal usage, it can save 45 to 50% for the domestic
user and 80% for the commercial user of the treated drinking water from
the mains. Having metered water is the best way of appreciating the difference.
So, why should people buy Rainwater Harvesting systems?
To save on water bills and show an appreciation for this increasingly
precious resource whilst making a difference to our environment.
How does rainwater harvesting work?
A storage tank is fitted to your storm water drain from your roof, and
falling rain enters the tank through a filter which removes leaves and
other matter. The storage tank is usually buried under car or vehicle
parks, a garden or under the entrance access or drive, and contains a
pump which pumps the rainwater to the building where it is piped to the
toilets, and to the outside taps. Above ground tanks are also available.
How much water can a system save?
Depending on your normal usage, it can save 30 to 50% of the treated drinking
water from the mains in houses and up to and up to 80% of the treated
drinking water in a business or commercial building.
What can you use the water for?
Filtered, untreated rainwater should only be used for non- drinking or
bathing purposes: toilet flushing, gardens and vehicle or yard wash downs.
How much does it cost?
Domestic systems can cost from about £2500 up to £4000 plus
including installation costs, depending on size of tank. Commercial systems
can cost a lot more depending on size and requirement, but usually have
a much quicker 'pay back' period due to the size of roof and high usage.
Could rainwater get into my drinking supply?
Not in a properly designed system, the pipe work is entirely separate
and should be identified as non-potable. BS8515:2009 stipulates that backflow
prevention should be fitted upstream of or at a point where any two systems
meet. This form of back flow prevention must be of type AA or AB Air gap
conforming to BS13076 and BS EN13077.
Do I need a big roof area to make it worthwhile?
No, most domestic roofs are more than adequate, but the bigger and flatter
the roof area, the more rain will be captured, and the more the rainwater
will substitute for treated mains water.
Is Rainwater Harvesting a new idea?
No, collection re-use of rainwater from roofs can be traced back thousands
of years in hot, dry countries around theMediterranean. In continental
Europe, some 100,000 are installed annually; Germany has been using and
refining the technology since the early 80s.
Can a roof affect the efficiency of a system?
Yes, all these need to be free-draining and suitable to stop debris from
entering the system. Other roofs such as green roofs etc absorb water
and results in less run off and more colouration.
This guide has been produced to assist professionals who are interested
in the specifications of rainwater harvesting systems. Enabling them to
make an informed choice of supplier based on the criteria set down in
BS8515:2009. At Combined Harvesters Ltd we are committed to a long term
approach to the supply of all rainwater harvesting and stormwater management
products, ensuring quality throughout the chain.
Save your water…save your money…save your environment.
Can I use rainwater for my garden?
Absolutely, in fact the water is a better quality with less harmfull chemicals.
More to follow soon.......