Buildings Sustainable homes
Zero CO2, Bristol,
> • Mid Street, South Nutfield, Surrey, a semi-rural social
attained level 5 of
housing venture built to level 5 by Raven Housing Trust;
the code (see page
opposite)
• Norbury Court, Staffordshire, an urban social housing
development built to code level 3 by Staffordshire
Housing Association.
All the projects were relatively small, each
comprising between two and six properties, including
private housing for sale and social housing for rent
and sale.
Most of the schemes have a high-quality, highly
insulated building shell with low air-permeability
that take advantage of passive solutions before adding
active or renewable features. These include low levels
of air-permeability, passive solar design strategies, low-
energy lighting, the use of environmentally benign
materials, low-water-use sanitaryware, and rainwater
harvesting.
The three projects that achieved level 5 of the code
also included renewable energy technologies, such as
photovoltaics and biomass boilers.
The overall technical performance for the
developments varied according to the code level
achieved, with low-e double or triple glazing and wall
U-values ranging from 0.10W/sq m K at code level 5,
Mandatory minimum standards in the code*
to 0.29W/sq m K at code level 3.
Code Level Category Minimum standard Air permeability test results were also roughly in line
1(H) Energy/CO2 10%
with expectations, ranging from 1.7 cu m/h5@ 0pa at
2(H H) Percentage 18% code level 5 up to 5.63 cu m/h@50pa for code level 3.
3(H H H) improvement over 25%
4(H H H H) Target Emission 44%
5(H H H H H) Rate (TER) as 100% Code categories
6(H H H H H H) determined by A ‘zero carbon home’ (heating, lighting, hot water and all
There are nine categories of standards in the code
the 2006 Building other energy uses in the home)
Regulation
that homes are judged against: energy/CO2; water;
Standards
materials; surface water run-off; waste; pollution;
1(H) Water 120 litres per person per day health and well-being; management; and ecology.
2(H H) Internal potable 105 l/p/d
Only the first five of these categories set minimum
3(H H H) water consumption 105 l/p/d
4(H H H H) measured in litres 80 l/p/d
requirements for meeting different levels of the code
5(H H H H H) per person per day 80 l/p/d
(see table, left). The requirements for three of these
6(H H H H H H) (l/p/d)
groups – materials, surface water and waste – are at
1(H) Materials At least three of the following five key elements of
entry level and apply only to code level 1.
Environmental construction are specified to achieve a relevant
impact of materials Green Guide 2007 rating of A+ to D
The overall ‘scoring’ of a property against the code to
• Roof
establish which level it is at, is derived from the ‘credits’
• External walls
• Internal walls (including separating walls)
the property achieves across all nine categories – for
• Upper and ground floors (incl separating walls) levels 1 to 6 the respective minimum scores required
• Windows
are 36, 48, 57, 68, 84 and 90.
1(H) Surface water Ensure that peak rate of run-off is no greater for the
Run-off developed site than for the pre-developed site. This
surface water should comply with the Interim Code of Practice for
Lessons learned
management Sustainable Drainage Systems
But most importantly, a number of key ‘lessons

learned’ were revealed about how to design and
1(H) Waste Ensure there is a site waste management plan in construct a home from scratch to meet CSH standards,
Construction site operation which requires the monitoring of waste
waste management on-site in accordance with the best practice and the
says GHA.
defined waste groups. It must also include procedures Fundamental to creating a home to high levels of
to sort and divert waste landfill according to the defined
the code is the need for a holistic approach to be taken
waste groups. This must be performed either on-site or
through a licensed external contractor, in accordance
towards the design at the earliest possible stage, with a
with best practice
detailed knowledge of, and careful consideration given
Household The legal requirement is set out in the Household to, the CSH criteria. This will help give the whole team
waste storage Waste Recycling Act 2003. The size, type and number
a greater understanding of the implications to achieve
of containers may be set out by the Waste Collection
Authority using their statutory powers
the low U-values and low levels of air permeability
required.
*Four other standards are not mandatory but do contribute to a property’s overall score against the code to establish its
code level: pollution; health and well-being; management; and ecology For example, if developers have previously used
Source: UK Department for Communities and Local Government, Code for Sustainable Homes, February 2008
www.communities.gov.uk/thecode
brick and block cavity wall construction, they may be >
28 CIBSE Journal August 2009 www.cibsejournal.com
CIBSEaug09 pp26-31 Homes.indd 28 23/7/09 14:53:13
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