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Hi, I am having my flat rewired and the shower room in onto the bedroom. I asked the electrician to install a separate switch for the fan and the light so I can have discretion on when each is used.

He has put one switch in for both with an isolator switch above the door.

Where this could essentially do what I want it to, it's quite high and inconvenient but he says that according to regulations I can't turn the fan on and off the way I want to. This makes no sense to me as if I simply wanted to go in to look in the mirror and not use hot water, I would have to have the fan running. Is it possible and permissible under regulation to have this split on a 2-gang switch the way I want it?

Thanks for your recommendations, to preface I have very little (read none) electrical knowledge so if anyone is able to answer in very simple terms I'd appreciate it!
 
I think it might depend on whether the bathroom has another form of ventilation. ie a window.
In my house, when we bought it 11 years ago as a new build, the bathroom and ensuite have a 2 gang switch. 1 switch for light, another for fan. Both rooms have a window.
The downstairs WC has a run on timer fan, with 3 pole isolator. So fan comes on with light and stays on until timer runs down. No window.
I don't think the building regs will have changed since then concerning ventilation.
 
A new bathroom (England & Wales) has to have mechanical ventilation, with or without an opening window (think it changed 2010?);

Building Regulations: Need for additional ventilation | Kitchens and bathrooms | Planning Portal - https://www.planningportal.co.uk/info/200130/common_projects/34/kitchens_and_bathrooms/6

If your refurbishing an existing bathroom it should have no less than the existing ventilation, or not make it worse.
A new bathroom should have a fan which extracts at a rate of at least 15 litres per minute and continues to run for 15 minutes after the light has been switched off.
 
Thanks for your replies.
A new bathroom (England & Wales) has to have mechanical ventilation, with or without an opening window (think it changed 2010?);

Building Regulations: Need for additional ventilation | Kitchens and bathrooms | Planning Portal - https://www.planningportal.co.uk/info/200130/common_projects/34/kitchens_and_bathrooms/6

If your refurbishing an existing bathroom it should have no less than the existing ventilation, or not make it worse.
A new bathroom should have a fan which extracts at a rate of at least 15 litres per minute and continues to run for 15 minutes after the light has been switched off.

Thanks, to clarify though, there is no other ventilation (no window) but it will have a fan that meets the regulations of extraction.

But do the regulations say anything about being able to have the light on when no extraction is running? This is the fundamental point I am trying to get an answer on. I could simply go into the bathroom with no light on and not turn the extractor on if I'm trying to find something for example, but that seems stupid. It seems obvious to me that you should be able to have the light on with no fan running if you so choose.

I can also achieve this by simply turning the isolator off, but this is annoying, you'd want the switch on the same socket as the light.
 
^^
As I originally stated, if no bco then you can ask your spark to do as you want
 
If you haven't anything in there at the mo, you can do what you want. And as Murdoch is exclaiming, unless the local building control come a knocking, you can do as you please. Not likely to retrospectively tell you to knock your house down!

Perhaps we should be praising your sparks, for doing as per building regs :)
 
The building regulations require a timed fan for a bathroom without a window however I can’t see anything that says it must come on with the light.
So a 2 gang switch is acceptable if you don’t want the fan to come on with the light if you say require to use the loo( not a number 2)
However if you shower/bath then turning on the other switch will run the fan and by turning if off when done , the fan will still run to the required time it’s set for (15 minutes say)
This is the way I’ve always done it on say new builds and the NHBC have no problem with it as they always check it’s timed if applicable.
 
The building regulations require a timed fan for a bathroom without a window however I can’t see anything that says it must come on with the light.
The planning portal ref @Midwest has provided above implies the fan should come on with the light and says it should run 15mins after the light is turned off :) .
 
The planning portal ref @Midwest has provided above implies the fan should come on with the light and says it should run 15mins after the light is turned off :) .
The only thing I can see in part F is that for intermittent fan controls in a room without natural light a 15 minute overrun is required and the fan could be controlled with the main light but not must be controlled by the main light.
I could be looking in the wrong place but I can’t see a rule saying must come on with the light.
 
maybe put a second switch ( make existing a 2 gang if it's a plate switch for the light) in series with the light switch. then depending on the state of the 2nd switch, fan will come on with light or not.
 
The only thing I can see in part F is that for intermittent fan controls in a room without natural light a 15 minute overrun is required and the fan could be controlled with the main light but not must be controlled by the main light.
I could be looking in the wrong place but I can’t see a rule saying must come on with the light.
I just had a looky look too - I agree. And it says the fan should be able to be manually operated. So I think the planners have made an interpretation of the regs that isn't what was actually written :)
 
I just had a looky look too - I agree. And it says the fan should be able to be manually operated. So I think the planners have made an interpretation of the regs that isn't what was actually written :)
Like I say I have never been pulled by the building inspector.
As long as he turns the switch on (2 gang separate switch for fan) and turns it off and the fan runs off the timer he’s happy for window less rooms be it utilities and bathroom/toilets.
I don’t think he timed them tho :)
 
The planning portal ref @Midwest has provided above implies the fan should come on with the light and says it should run 15mins after the light is turned off :) .

And people wonder why the Grenfell disaster happened.

The Planning Regs are the responsibility of the DCLG - they write AWFUL documents and need to be held accoutantable ......
 
The only thing I can see in part F is that for intermittent fan controls in a room without natural light a 15 minute overrun is required and the fan could be controlled with the main light but not must be controlled by the main light.
I could be looking in the wrong place but I can’t see a rule saying must come on with the light.

I have been giving a pursue of the approved document F, as opposed to the Planning Portal statement, always ready to correct myself.

Firstly it does state that extraction to the outside is required for kitchens, bathrooms, utility rooms & sanity accommodation (5.5), simples.

As to the control of said ventilation, it slightly less clear (for me). For a room without opening window, an intermittent extraction should have a fifteen minutes overrun. In rooms with no natural light, the fans should be controlled by the operation of the main room light switch (Table 5.2A) (not a direct quote, but all I can be arsed to type).
 
Could be, never used one so have know knowledge.
Why the dumb Adam? I did say it was possibly correct and that I had never used one, quite what's dumb about that reply is a dumb response on your part, but hey ho we are all allowed to respond how we feel however dumb it may be to the dumb person responding with a dumb reply.
 

Reply to Customer Question: Two gang switch for light & fan? in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net

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