Push Fit PL lamps and Buidling Regulations

Background to PL lamps/ PL Light Bulbs and the Building Regulations

Current building regulations are very strict in trying to preserve energy and and ensure that new build properties are consistent with environmental policies. To this effect there have been strict regulations in place for a number of years on important aspects like the thickness of loft and cavity wall  insulation. More recently these have been complemented by Building Regulations part L1 legislation governing the use of energy saving light bulbs to conserve energy in the property. This legislation in a nutshell says that new dwelling must install a percentage, normally around 33%,  of energy saving light bulbs and it must not be possible to swap these light bulbs for traditional incandescent ones. For this reason the standard bayonet and edison screw type energy saving light bulbs fittings are not permitted as the bulbs could be changed for less energy efficient ones at a later stage. The approach that has been adopted is to fit push fit PL lamps which are light bulbs with a specially designed cap which is only compatible with matching holders. This way the building inspector can be fairly assured that the energy conservation will continue as only the PL Lamp can be fitted, unless of course the consumer changes the light fitting!

More detail of the the G24Q and GX24Q Cap fittings

One of the most standard cap fittings is the G24Q and GX24Q cap fittings which are shown in the following  image MR16 CFL Bulb . If you take a look at this image then you will see that all of these family of cap fittings are 4 pin and have a cap of similar proportions. Accordingly you might think that they will all fit in the same lighting fixtures or pendants. However, if you look in more detail you will see that there are small notches that are placed at different positions on the cap base and it is the positioning of these notches which governs the compatibility with the lighting fixture. Clearly the building regulation people and potentially the lighting fixture manufacturers not only want to ensure that energy saving PL light bulb are fitted, but also to ensure that ones of the correct wattage are used. This can be important from the manufacturers perspective to ensure that the fitting is not overloaded or that excessive heat is not produced. The main driver from the regulatory body is going to be to stop people putting higher wattage light bulbs in the fittings and as a consequence not making the energy saving! Now it is not too restrictive as there is not a 1:1 mapping between the PL light bulbs and fixtures and quite often a fitting will take more than one of the bulb derivatives. As a practical examples the normal ceiling lighting pendents will normally accept the G24-Q1 and the G24-Q2 push fit PL lamps, so the important thing here is to check first.

The other important aspect to meet the building regulations part L1 legislation is that the actual light bulbs used must be of high efficiency. This meas that they must produce at least 40 lumens of light output for each watt of electricity consumption. This means that CFL technology or LED bulbs need to be used as halogen bulbs would not meet these targets. There is one other way to meet the legislation and that is to fit motion sensors to the rooms so that the lights only come on when needed and accordingly this will minimise any electrical energy waste.

So the picture is quite complex but I hope that this brief overview starts to clarify some of the main issues around the use of PL lamps and the interrelationship with the Building Regulations part L1 legislation.

One thought on “Push Fit PL lamps and Buidling Regulations”

  1. Thanks for publishing this. We’ve just returned to the UK after 3 years, and I was completely stumped as to these fittings when we moved into a new build. Your figures also explains why the fitting is only on ‘some’ of the fixtures.

    Now I know what I need to buy at least. Worrying that 3 supermarkets I visited are not carrying them…

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