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Changing of mr16 halogen to gu10 led or mr16 led in bathroom

Hi all,

Currently in my upstairs bathroom are 6 dimmable spotlight halogen 50W bulbs running on 12v MR16 fittings (each with own transformer in the loft). My bathroom has a shower & bath, none of the lights are directly above these (unsure of height of ceiling, but average and think fall under zone 3).

I want to fit LED bulbs to save on energy. I would have to fit at least one LED transformer, and replace all the bulbs with LED MR16 dimmable bulbs. Alternatively I can just remove the transformers, get GU10 fittings and attach these with 6 x GU10 LED 230V bulbs. I think the latter would be easier. I therefore have a few questions:

1) I assume I need to notify council of this work due to building regulations in 'special' area. Would this be the case if I were to simply change the transformers in the loft & the bulbs so I could use MR16 LED bulbs?

2) Assume I keep the original 50w halogens, and a transformer blew (which has happened for 1 fitting) would I need to notify council to just replace this transformer with exact same model?

3) If I changed to GU10 230v fittings (and informed the council as I assume I would need to as more substantial work), are these safe for the bathroom use?


4 Answers from MyBuilder Electricians

Best Answer


Wrong information has been given to you.

Bathroom is defined as a special area. Replacing LIKE For LIKE does not require notification, adding or ALTERATION of the circuit does. You will need to make alterations to the circuit to remove the transformers, therefore, notifiable. Notifiable because LBC will send someone in to test and verify their readings against those permissible dependent on your home earthing system. Who said the original circuit was safe? This is why alterations need testing, not just additions.

Whilst you are installing LED lamps, it doesn't prevent a subsequent owner replacing with Halogens, make sure that you follow the manufacturers recommendations regarding proximity of fitting to surrounding supports and insulation


Answered 14th Dec 2015

Hi Andy,

You wouldn't need to notify the council if your taking out transformers and putting in LED lamps with a GU10 fitting, the resistance to the circuit hasn't been changed IE lengthened. GU10 is the way to go MR16 LED would be more expensive I would imagine.

They are safe for the bathroom as long as they are above 2.25m if not put in IP rated down lighters, I generally put IP rated fittings in bathrooms anyhow regardless of height for a bit of protection from steam and moisture
Hope that helps


Answered 10th Dec 2015

Hi Andy,
1) If you wish to change the transformers and bulbs you DO NOT have to notify Building Control.
2) Again you DO NOT have to notify Building Control if you want to replace a transformer.
3) If you wish to replace your current M16 Spots for GU10 spots as long as you don't add to the circuit i.e. add more cable, you can do that too without notification. All these come under Minor Works despite being in the Bathroom.
And finally yes they are safe for bathroom use, however if they fall within the Zone 1 or 2 height which is 2.25m from the floor they must be suitably IP rated for that zone. If your ceiling is higher than 2.25m's then you can use any GU10 spot although I would recommend one that is fire rated.

Hope that all helps.


Andy Hough
NICEIC Domestic Electrician


Answered 10th Dec 2015

The question it worth changing these transformers, potentially not connecting the new transformers satisfactorily, thus giving rise to the risk of the terminations over heating which could lead to a fire. At that point, that's when the insurance company will get involved to find the slightest loop hole which allows them to not pay a claim. If you get a qualified electrician to do the works, the electrician will complete the works in line with the regs, test the circuit to ensure the fault loop impedance is low enough for the circuit breaker and notify building control that the works have been carried out. This takes it out of the home owners hands and places the responsibility into the electricians hands. No insurance company will argue with an NICEIC registered electrician. And yes any electrical works apart from changing a lamp 'HAS' to be notified. Alfie


Answered 30th Mar 2016

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