Principles of Sustainable Energy Management
The Energy Hierarchy sets out the core principles of sustainable energy management in building design and operation.
The Energy Hierarchy
The purpose of the energy hierarchy is to provide a principled approach to designing a building with sustainable energy performance in mind. The hierarchy is being embedded into policy and practice through DCLG’s ongoing work on Low and Zero Carbon buildings, Building Regulations, and through planning policy. T here are many possible sustainable energy solutions available to building designers and developers, as well as property and facility managers. Some are applicable in all development types and others are specific to particular development sectors, locations or style of architecture. Further details are provided in the solutions section of this module.
The diagram below illustrates the stepped approached to designing for sustainable energy management that should be used within new build projects and refurbishments.
Following the energy hierarchy is one of the most effective ways in which to reduce the environmental impacts of buildings. Measures are listed below:
1. Reduce energy demand
Reduce the quantity of energy required for heating, lighting and cooling via fabric efficiency and passive design:
- insulation better than the Part L maximum values for walls, roof, floor, windows and doors
- air-leakage level better than the Part L maximum
- enhanced insulation of pipes, ducts and vessels
- solar control glass and/or shading louvres
- Use natural environmental systems instead of artificial systems, such as passive solar gains, natural ventilation and natural daylighting
2. Energy efficiency
Use energy required to provide occupant comfort and safety efficiently:
- Energy efficient services, appliances and controls, such as
- high efficiency condensing boilers
- high efficiency chillers
- underfloor heating
- chilled beams
- pumps and fans with variable speed motors (DC or EC)
- pipework and ductwork with larger diameters
- efficient controls systems
- Low-energy lighting, such as:
- CFL (compact fluorescent lighting)
- LED (light emitting diode) bulbs
- natural daylight and presence detection controls
- Energy efficient white goods:
- fridge
- freezer
- washing machine
- tumble-dryer
- dishwasher
3. On-site renewable, low and zero carbon technologies
Replace or minimise the use of finite and polluting fossil fuels:
- Low or zero carbon (LZC) micro-generation technologies, to provide as much energy as is technically and economically feasible:
- combined heat and power
- biomass boiler
- heat pumps (either ground source or air source)
- solar water heating
- solar photovoltaic panels
- wind turbines
- small hydro power
- Purchase all remaining electricity requirements on a Green Energy Tariff (electricity generated from off-site renewable energy) that supports the development of new large-scale renewable energy generation and infrastructure
4. Allowable solutions
If a building consumes fossil-fuel for heat and power, it may still be classified as ‘zero carbon’ if the same quantity of resulting CO2 emissions are offset elsewhere. The offsetting solutions are categorised as ‘allowable solutions’. The following solutions may be considered as allowable solutions:
- Reducing the energy consumption of other buildings elsewhere
- Investment in macro-scale energy solutions, such as a district heating network or wind farm
- Payment into a community investment fund