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2. Energy Efficiency

There follows a number of different considerations around the subject of energy efficiency, including whether or not an application for Building Regulations approval might be required for specific projects. More information about the range of energy efficiency measures possible can be found on the Energy Saving Trust's (EST) website.

Solar panels

If you wish to add a solar panel to the roof of your home, Building Regulations approval is likely to be needed. The adequacy of the existing roof to carry the load (weight) from the panel will need to be checked and proven. Some strengthening work may be needed. Also as, for example, roof tiles will be removed or omitted to locate and fix the panel(s) the reinstatement should ensure the roof has adequate weather resistance.

Internal lights

Fixed internal lighting will need to have reasonable provision made to obtain the benefits of efficient electric lighting whenever:

  • a dwelling is extended
  • a new dwelling is created from a material change of use
  • an existing lighting system is being replaced as part of re-wiring works,

A way of making your internal lighting more energy efficient is to provide lighting fittings (including lamp, control gear and appropriate housing, reflector, shade or diffuser or other device for controlling the output light) that only take lamps having a luminous efficacy greater then 40 lumens per circuit watt.

The type of light fittings that would meet the above requirements, are fluorescent and compact fluorescent light fittings. Fittings for GLS tungsten lamps with bayonet cap or Edison screw bases, or tungsten halogen lamps would not.

A general way of meeting these requirements is to provide one fitting for every:

  • 25m2 of dwelling floor area (excluding garages); or
  • one per four fixed light fittings

Lighting fittings in less used areas such as cupboards and other storage areas would not count towards a fitting. If constructing an extension, it may be more appropriate to install the energy efficient light fitting in a location that is not part of the building work. e.g. to replace the fitting in the hall or landing when creating a new room - depending on the likely extent of use of the new room light compared to the hall or landing.

Insulation in a loft

Installing insulation to your loft area requires an application for approval under the Building Regulations. Care should be taken not to block any ventilation at the edges (eaves).

Re-cycling water tanks

These are tanks that recycle surface water (rainwater) that is collected from the roof and ground and so that it can then be re-used within the house for other uses such as toilet flushing or general washing. These tanks are generally placed underground in the rear garden if there is space. An application under the Building Regulations is required to check the new drainage system running to the tank.


Any new radiator installed will require a thermostatic radiator valve (TRV) to be installed. A TRV gives better control over the individual room temperatures. It is also encouraged to place TRV's on existing radiators.

Pipe lagging

This does not normally require Building Regulations approval.