Cardiff University, Welsh School of Architecture
Low and Zero Carbon Building Design
1. Current status
Almost half of overall energy consumption is attributed to heating, cooling, light and other services in buildings. In December 2006, the UK government published a consultation paper proposing a timeline and framework to promote sustainable and eventually zero carbon house design. Within the document, it is proposed that by 2016 all new homes in England will be required to achieve “zero carbon”, while in Wales this aspiration is for all new buildings to achieve a Low carbon standard by 2011.2. Zero carbon
Current definitions for low and zero carbon homes can be defined as follows:“Zero Carbon Developments”:
“A zero carbon development is one that achieves zero net carbon emissions from energy use on site, on an annual basis.”
“Low Carbon Development”:
“A low carbon development is one that achieves a reduction in net carbon emissions of 50% or more from energy use on site, on an annual basis.”
A broader definition of zero carbon building would ensure that the renewable energy generated on site would also offset the embodied carbon due to the construction and manufacture of the buildings as well as the carbon emissions resulting from the occupants’ lifestyle such as those due to transport, food and products consumed.
3. Methodology
The design procedure of low to zero carbon buildings should be carried out implementing the following steps.- Briefing At the beginning of the development process it is important that all partners sign up to the carbon and energy ambitions for the buildings or development. These should be made a contractual requirement in order to ensure delivery.
- Design: Analysis of Site Conditions: The analysis of natural climatic and microclimatic conditions is of primary importance in order to make use of the local climatic conditions as well as appropriate site planning.
- 3. Design: Application of passive design methods Through detailed building form and building fabric design to minimize the load requirement from heating, cooling and lighting with the aids of building simulation.
- 4. Design: Active systems Identify appropriate energy efficient mechanical systems and renewable energy systems, including photovoltaic, wind turbines, solar hot water and heating system, under-floor heating, radiant cooling, and heat pumps. Through the application of modeling systems such as using TRNSYS these system designs can be optimized.
- 5. Construction During the construction phase it is vital that all partners understand their role in delivering the low to zero carbon ambition. This embraces the role of the labourer, ensuring continuity in insulation or air permeability barrier through to the services engineer, ensuring delivery of the system as designed.
- 6. Commissioning Commissioning should be undertaken in all seasons to ensure that the systems are optimised. This will also ensure functioning of systems to design standards.
- 7. Occupation During occupation monitoring and ideally post occupancy evaluation in its fullest sense should be undertaken. This will ensure that carbon savings on paper are delivered, as well as enabling learning from experience.
Further information
For more information please contact Julie Gwilliam:Email: gwilliamja@cf.ac.uk
Tel: 029 2087 5977
Fax: 029 2087