/ Home & Energy

Specialist light bulb fittings stole my energy saving choice

While not ‘de-lighted’, I’m certainly not mourning the passing of the incandescent light bulb. I think energy efficiency is a good thing and have had no problems with low-energy bulbs. That’s until I moved house…

And thanks to an unnamed energy company and their CERT (Carbon Emissions Reduction Target) requirements, until recently, I had a decent stash of CFLs. I reckon these would have lasted me another five years before I had to actually go and buy a new bulb.

But alas, my stash is no more. Well it is; it’s just no longer with me. The reason? I moved house into a new build property. And in order to meet ‘Part L’ of the building regulations – where 30% of lighting must be low energy – my house uses non-standard light fittings ‘to ensure only low-energy lamps can be used’. So it’s bye, bye to my bulb stash, hello three-pin light bulbs.

If you’ve not already met the three-pin light bulb, let me introduce you. While it may look like a normal low-energy bulb, it’s far from it.

The BC3 (to give it its correct name) is a non-standard, three-pin CFL light bulb, which meant my small stash of two-pin bayonets wouldn’t fit into my new home’s three-pin light fittings. So they all had to be donated to the future tenant of my old flat.

Where’s my choice of bulb?

Don’t get me wrong. I don’t have anything against energy efficiency, I think it’s a good thing (but I know not everyone likes energy-saving bulbs).

I’ve been using low-energy bulbs since my Dad packed a few in my bag when I went off to uni. And I have nothing against the BC3 either. Except… I like choice. And in this case my choice has been taken from me. I can’t get these three-pin bulbs in my local shop and they cost more than I would expect to pay for a light bulb.

But more importantly, unless there are three-pin LED equivalents out there, I can’t upgrade to a more efficient bulb. And, to me, that seems to go against not only the rule, but the spirit of the building regulations.

I suppose I could change my light fittings, but the cost of getting in someone who knows what they’re doing without blowing the place up, would probably far exceed any savings I might make. And although the company offers an adapter to fit other bulbs, they’re only for what they call ‘standard four-pin CFLs’, which again isn’t a bayonet or screw fitting!

So, do any of you bright sparks out there have a solution for my light bulb dilemma? Or will I just have to sit in the dark?

Prudence says:
7 July 2012

3-pin (BC3) bulbs have been around for decades and can easily be obtained in Incandescent versions – in fact the irony is that they are easier to buy in Incandescent versions than ordinary BC incandescent bulbs.

BC3’s were usually used in things like shop display light fittings (often in a Reflector lamp (eg R80) or in a Crown Silvered lamp) or in very high wattage fittings (e.g. school classrooms, factories). They are still readily available for such purposes because the [crazy] move to so-called energy saving lamps doesn’t fully apply to places like shops and pubs where there are ‘commercial interests’ (i.e. profit) to be concerned about.

If you want to use incandescent lamps in your new house, chances are that you can easily buy them, albeit at an over-inflated price, from your local shop fitting company or from an electrical wholesaler in your area. That said, 3-pin CFL’s are usually priced at a premium compared to ‘ordinary’ CFL’s, so the purchase price may not be significantly different if you buy Incandescents.

Alternatively, change the fittings. A decent sparky (and I’m one, though no longer working as such) won’t charge you very much to swap the lamp holders over at all and in fact, the wiring regulations don’t prevent anyone **who is competent** and who feels confident in what they are doing, from changing light fittings at all. After all, if you went to your local department store and saw a nice new light fitting that you wanted in your lounge, it is expected that you’ll either get a sparky in and not have to pay as much as the fitting was worth to fit it, or that you will be able to follow the instructions to do it yourself. It’s only if you actually change the fixed wiring or are doing the work in a kitchen, bathroom or other “special location” (such as outside) that you would need to be wary of the wiring regs and make sure you got a certified person in.


Thanks for the warning – Though I’m unlikely to move into a new build. It is easy enough to re-wire a light socket – I also used to be a “sparky”.

Paulo says:
8 July 2012

Good to know this is an old standard. And judging from the comments only sparky’s like the variety of lamps.

I happen to feel competent to do sparky’s work in my house (even though I believe I am not expected to if in bathrooms or kitchens), but I agree with Jo, moving to low energy should not be an excuse to create a profusion of standards that make sourcing bulbs difficult and as a result expensive. It used to be the case that anyone would be able to change a light bulb but it is becoming a complicated task…

And don’t get me started on the 12V halogen’s and led’s that need special transformers…


I am old enough to remember going with my father to the electricity showroom, handing over a dud lightbulb, and getting a replacement free of charge! Lightbulbs were so cheap they could give them away and they were actually in the business of selling electricity. For most of my life, lighting has been such a straightforward matter with standardised, cheap, efficient, lamps that were readily interchangeable. In recent years it has become a real pain with non-interchangeable caps, bulb shapes that do not conform to fittings, an impenetrable choice [or chioce if you prefer – see the headline] of output per watt, and incredible [and unpredictable] variations in illumination performance. Keeping spare bulbs is now extremely expensive but still necessary because local retailers only stock a limited range.


As a matter of course I only fit “conventional” Bayonet or ES fitments, and pull out any others and replace them with the former. Then I can use widely available and frequently dicounted CFLs or LED bulbs.

As Incandescent bulbs are increasingly limited in availablity, it seems a daft notion to interpret Part L like this – is this general, or some idiosynchracy of your developer and /or local Building Inspector?

Ian F says:
9 July 2012

The builder has no choice but to avoid standard bayonet and ES fittings.

ref http://www.planningportal.gov.uk/buildingregulations/approveddocuments/partl/faqs Q19


I have not met BC3 3-pin CFLs but if I did I would change to good old-fashioned bayonet fittings. It’s good to read that Jo passed on her unwanted lamps, rather than put them in the bin.

Many people were given ‘free’ CFLs by their energy company without any thought about whether the caps would match the fittings. I suggest that these are given to friends or given away via Freecycle, etc.

Shop around and branded CFLs can sometimes be bought at bargain prices. I have at least six Philips lamps that cost 10p each, a couple of years ago. I have not needed them yet because it is several years since I had a CFL fail.

Em says:
8 July 2012

I can see this risks turning into a: “How many Which? Conversationalists does it take to change a light bulb?” joke. Anyway –

1) Contact the builder and say you are not happy. At the very least they might give you a few spare bulbs as a gesture of goodwill – particularly if they know you work for Which?

2) Consider getting some BC3 to 4-pin CFL adaptors (part F1271 or F1272). Or again, ask your builder to supply them. The reason they like the BC3 fitment is it complies with the Part-L Regs, but is cheaper for them to supply and fit than a proper energy-saving light with integrated control gear. CFL 4-pin bulbs are a good, cheap alternative, when bought from a trade outlet (TLC, etc.). And they are more environmentally-friendly than chucking the electronics away every time a light bulb fails, as you do with consumer CFL bulbs. I installed some over my kitchen work areas, in light fittings designed for commercial use (offices, etc.) and very good they are too.

3) LED bulbs (I have several in my home) are certainly not cheap to buy, and they are not that much more efficient that a good CFL installation. Also the colour-rendering can be pretty poor. I have some in my hallway, and my dinner guests can look decidedly ill when leaving. I have to remind myself that it is not my cooking!

4) Just live with the relatively high cost of replacement bulbs. How long do you intend to stay in your latest property? These bulbs should last about 5 years and, over the lifetime of the bulb, you will spend £20-£30 on electricity alone. Consider that that would have been 5 times as much with a tungsten filament bulb, so maybe £10 per replacement is not so bad after all.

When you compare it to the cost of the many other proprietary consumables we have to buy from time to time, I wouldn’t lose too much sleep over it. Think of the extra expense of lying in bed with the lights on!