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What should be the overall approach to reducing energy use?
- Adopt the 'Energy Hierarchy', as set out in the Regional Planning Guidance (2002 and revised 2004) which recommends that the following order of priority is pursued in all development schemes:
- Reduce the need for energy
- Use energy more efficiently
- Shift to using renewable energy (including purchase of green power from an accredited scheme)
- Ensure that any continuing use of fossil fuels is clean and efficient (for heating and co-generation)
- Minimise embodied energy in construction by choice of materials and systems.
How can solar gain be maximised to reduce heating requirements?
- Avoid overshadowing from nearby buildings by allowing adequate spacing and be aware of permanent shading from trees (although they can provide shelter from winds to reduce heat loss).
- Orientate the main building elevations to face south and size the windows in order to provide long periods of sun and daylight.
- Consider the use of roof lights and atriums to bring light and solar heat into the centre of buildings.
- Be aware of the overheating effects of solar gain in summer months and design accordingly.
How can heat loss be reduced?
- Explore the advantages of designs that utilise high thermal mass (see Building Design and Specification).
- Ensure an airtight construction with adequate controlled ventilation.
- Reduce the area of exposed external surface by selection of building type / design.
- Provide substantial layers of insulation and maximum draught proofing.
- Include unheated ‘buffer’ spaces attached to main building areas to store the sun’s heat and reduce exposure to cold (e.g. porches, conservatories and atriums).
- Utilise advanced glazing systems giving preference to low-E (emissivity) glass.
- Consider secondary glazing systems as a simple retrofit measure.
Why should and how can Building Regulations be exceeded?
- Treat UK building regulations as a minimum standard which can be raised by limited extra investment, often giving an effective payback as well as wider environmental benefit.
- Aim for the highest rating by use of a recognised assessment method (see ‘Tools for Assessing Environmental Performance’ in Further Resources and employ it as a positive marketing point for the property.
- Investigate the potential for zero heating (i.e. heating only from solar gain, plus the heat given off by electrical equipment and occupational activity), especially in houses and leisure/commercial buildings - which will normally increase their marketability.
If heating systems are required, what are the most energy efficient solutions?
- Size the system correctly, as oversizing is common bad practice, and use zoning where appropriate.
- Install high efficiency boilers (note: consider condensing systems) with understandable heating controls and high standards of insulation throughout (storage cylinders, pipework etc), and ensure operators are trained in their use.
- Consider wood fuel boilers.
- For larger buildings, consider the potential for connecting to a community district heating or combined heat and power (CHP) scheme, including the option of establishing a new shared scheme in the area.
How can energy use be managed for the benefit of building occupants?
- Reduce the need for hot water as far as possible - install low consumption appliances (e.g. showers).
- Opt for ‘A’ rated energy appliances with sophisticated timers where appropriate.
- Eliminate the need for air conditioning by maximising opportunities for natural ventilation.
- Ensure that heating, lighting and ventilation controls can be easily set to meet the needs of occupants.
- Consider remote rather than central systems where dictated by long pipe runs and low demand.
- Consider installing active solar water systems (see Renewable Energy.)
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