2007-06-20
The Code for Sustainable Homes means that designers will be encouraged to create ultra low energy houses, with renewable energy technologies (as well as water saving features) set to become standard practice. BSRIA's James Parker puts the Code into perspective:
Sustainability is rapidly becoming the key issue for new housing. In order to drive the market further into a greener future, the department for Communities and Local Government (CLG) has launched what it calls 'A step-change in sustainable home building practice' - the Code for Sustainable Homes.
The Code was launched in December 2006, with the technical documents released in April 2007. The Code builds on BRE's EcoHomes system - the domestic version of the BREEAM assessment tool.
The Code works by using a point-scoring assessment method in nine design categories. The points from these categories are added together to arrive at a whole-house star rating. One star is the entry level (a basic sustainable home), with six stars reserved for truly carbon-neutral homes. The levels in between reflect increasingly greener hues of sustainability.
However, house designers must reach the minimum standard of one star in two key categories, energy and carbon dioxide (CO2), in order to qualify for points in the other seven categories.
Energy and CO2 emissions:
Energy and CO2 are based on the Target Emission Rate (TER) as used in Part L of the 2006 Building Regulations. The key measurement is the percentage improvement over the 2006 requirements. This ranges from a 10% improvement for the one star rating, up to the impressive zero-carbon home for a six-star rating.
As well as the minimum standards, points are awarded for the level of improvement of overall energy use. This is broken down into smaller increments (15 levels).
Other points in this category are awarded for various factors, for which there are no minimum standards. The building fabric is assessed based on the heat loss parameter - a measure on how much heat is lost through walls. Points are available for heat loss values less than 1.3 and more for heat loss values less than 1.1.
Points for dedicated energy-efficient fittings for internal lighting are awarded where the percentage of fixed fittings are greater than 40%, with extra points for more than 75%.
External lighting is covered with points for energy efficient fittings, as is security lighting of 150W or less, along with movement or daylight sensors. Points are awarded when at least 10% of the energy demand is supplied from local renewable or low carbon energy sources.
Pollution:
There are no minimum standards for the pollution effects of sustainable homes house, only point-scoring features. Points are gained for the use of insulating material that avoid substances that have a global warming potential (gwp) of 5 or more (referenced to CO2 which has a gwp of 1). Points are also awarded for low emissions of nitrous oxide (Nox) from space heating and hot water systems.
Water, materials, waste, health and wellbeing are other aspects, but do not affect electrical contractors and installers in the same way, so James Parker's information on these topics has been omitted (Editor).
Management:
Management covers both construction and post construction management. On the construction side, points are awarded for membership of the Considerate Constructors Scheme and on a commitment and strategy to reduce the harmful effects of construction on the site environment.
Points are gained for the provision of Home User Guides, which are relevant to the operation, and environmental performance of the home.
Ecology:
The last category, ecology, looks at the effects of house building on existing flora and fauna. Points are gained for building on land with a low ecological value, adding ecological enhancements, protection of ecological features, and minor or positive changes in the ecological value of the site.
Supporting documents:
The technical documentation is due to be published by April this year, and will include a calculation and assessment tool.
The calculation tool will link to existing methods, which will provide some consistency across regulatory requirements. For example, the energy calculation will follow the same methodology for the system of energy performance certificates to be introduced in June 2007 as part of the UK's commitment to implement the Energy Performance of Buildings Directive (EPBD).
The Code will also share a common calculation tool for water efficiency with that being developed for the Building Regulations. This tool is already out for consultation.
BRE will train assessors for the Code. This will be similar to the BREEAM/EcoHomes training schemes. Assessors already accredited to carry out EcoHomes assessments will be re-trained through top-up courses.
While the Code is not mandatory, developers will be encouraged to follow it. The government is considering making the Code mandatory, possibly 2008 with the next changes to the Building Regulations. However, government-backed housing, such as those built for the Housing Corporation or English Partnerships, with have to reach set levels of the code.
Local authorities, many of which are currently working on new Local Development Frameworks, may also require certain levels to be met on some developments. BSRIA's experience has revealed that certain councils are already asking for EcoHomes assessments.
Mandatory or not, the Code is a step forward in an area of construction. Hopefully, the Code will have the desired effect of encouraging the take up of more sustainable practices and products by house builders.
The Code will have a knock-on effect across the industry, not just house builders, but materials manufacturers and suppliers and especially manufacturers of energy related products. Some will find their business increasing, while those with less environmentally-beneficial products will be left behind.
For more information contact Design & FM Innovation at BSRIA, tel: +44 (0) 1344 465600, email: energy@bsria.co.uk.
Note that BSRIA offers airtightness testing for dwellings (Building Regulations Part L1a).
|
Related contacts
|
BSRIA Ltd.,
Old Bracknell Lane West,
Bracknell, Berkshire RG12 7AH
Tel: +44 (0) 1344 465600
Fax: +44 (0) 1344 465626
Email: bsria@bsria.co.uk
Web: www.bsria.co.uk |
BSRIA
|
| For latest electrical industry news, register for Voltimum's free newsletter. |
|
|
Source: BSRIA - edited James Hunt |
Back