Lighting and New Building Regs

by Steve on June 5, 2009

Lighting and New Building Regs

Ammendments to the Building Regulations Part L came into effect on 6 April 2006.

Section L1A- New Build

Section L1B- Renovation


Lighting can account for as much as 20% of the average household’s electricity bill. Building regulations in the UK now state that in all new homes and extensions to existing properties, 1 in 4 of all the habitable rooms must have dedicated low energy lighting.

This means that in a new 3 bedroom house with a kitchen, bathroom and two reception rooms, at least 2 of the rooms must have dedicated low energy lighting installed. The landing & hallway can be regarded as one room.


A lamp defined as low energy must have a light output of 40 lumens per circuit watt. (Scotland 50 lumens)


Some approximate comparisons:


High output LED = 100-150 lumens per cct watt

HP Sodium Floodlight = 50-140 lumens per cct watt

Metal Halide = 70-120 lumens per cct watt

1 x Compact Fluorescent = 40-70 lumens per cct watt

1 x 12 volt 50watt halogen = 15-20 lumens per cct watt

GLS Incandescent = 10-17 lumens per cct watt


New Low Energy light fittings must also have a dedicated lampholder (such as SGU10) to prevent older higher usage lamps from being retrospectively installed.


Which new lamps are available now?

Many manufacturers are introducing new products on a regular basis.

They range from Low Energy CFL versions of standard BC & ES Incandescent GLS lamps to High Output LED. The following types are now widely available:

Compact Fluorescent (CFL)

The best choice for general lighting, as they produce a higher light output per circuit watt, use up to 80% less power than incandescent bulbs and do not reach high temperatures.


LED bulbs have made amazing advances and use very little power.

There are now high output LEDs available with the equivalent light output to 20w halogen.

They are great for effect lighting such as to highlight a shelf display, under cupboard lighting or mark the edge of garden decking and pathways.

Cold Cathode

These bulbs are great for outdoor signs, such as shop window displays, etc. They are also used in some recessed downlight products. The main advantage is that they do not heat up in the same was as an incandescent bulbs, and use up to 60% less energy.



The most efficient lighting for floodlighting large areas is still Sodium, however the standard 300 & 500 watt Linear Halogen lamps can now be directly replaced by 24watt CFL such as Edison’s EDJ118/24


Retrofit MR16 & GU10

With millions of Recessed Downlights already installed it is reassuring to know that retrofit lamps are now available as ‘Higher Efficiency’ and ‘Lower Energy’ options. The following article gives some of the available options:

Related articles:





Is Low Voltage Lighting the same as Low Energy?

Of course it’s not, but this is an informative article and worth a look:

Article: Is Low Voltage Lighting the same as Low Energy?


Electrician’s Guide to the Building Regulations


Download Part L here


Link to: City Electrical Factors– suppliers of Aurora & Low Energy Lighting products. Lighting design specialists.

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