Modifying stairway lighting circuit to incorporate loft conversion

[curium]

Hi,

I'm getting some quotes for a loft conversion. I'm trying to decide whether to go for a shell only quote or to include 1st and 2nd fix so I need to make my requirements clear.

I have a 2 storey house currently with a light in the entrance hallway and a light on the landing at the top of the stairs.

These 2 lights can be controlled by either of two 2-gang switches. One is located downstairs in the hallway and the other on the 1st floor landing.

If we convert the loft we'll have a 2nd storey (3rd?/loft) with a landing and lights before you enter into the loft conversion bedroom.

I would like a third 2-gang switch on this 2nd-floor landing that controls the lights on the 2nd-floor landing and the 1st-floor landing.

Ideally I would also want to convert the 1st-floor landing light from a 2-gang to a 3-gang so from that floor you can control the ground-floor entrance hallway lights, the 1st-floor lights and the 2nd-floor lights.

To further complicate matters I'm wondering if it is possible for these switches to be dimmers but I read somewhere that you can only have 1 dimmer switch on a 2-way lighting circuit. Is this true?

Is there a name for the lighting circuit I have described?

Many thanks

 

[Taylortwocities]

You would need to introduce an intermediate switch, probably on the first floor landing. Show us a pic of the wiring at this switch please.

Note that there are no intermediate dimmers, you could have a dimmer at either end of the two - way circuit. You are right, mostly you can’t have two dimmers on a circuit, but there are some master/slave combinations (Google is your friend) but be prepared to rewire/reconfigure your lighting circuits.
Another approach is to use smart light switches. There are some products that also support multi-switch configurations. But these need a lot of geeky app configuration, so maybe not for you unless you have a masters in computer science. Litewave does have products that aren’t quite so difficult.

Making the 2-gang switch into 3 gang to do what you want is another layer of difficulty. It may be possible if the existing cabling is kind, usually it isn’t. Be prepared to run more cables between the 3 floors.
One option is to look at wireless switching. Could give you the on/off stuff but dimming may not be on.
Sorry to be so negative.

Probably best to get some clever electrician on site to look at what you have and make a plan.

EDIT. To comply with building regs, you are going to need interlinked smoke alarms on all three floors. I guess you factored those in? You’ll need to rip up floors etc to cable those, so maybe a good time to rewire your light switching?

 

[curium]

Show us a pic of the wiring at this switch please.

It seems the electrician did put a cable in there labelled loft. This was from when we had some work done last year ahead of fitting a new kitchen.

Hopefully that will make wiring in the loft landing in the way I wish possible?

 

[Taylortwocities]

If that cable marked loft is 3 - core and earth you could use it to provide additional switching for the existing (1st floor light.)

If you want another light on the 2nd floor that can be switched from the 1st and 2nd floors then you will need a second 3-core&earth cable between the two switches. Also you’ll need to find a lighting circuit feed for the new light on the second floor. Not sure how you could engineer that as there does not appear to be a neutral in the 1st floor switch box.
Btw, that box is gonna need changing for a much deeper one.

All of this is way outside the scope of advice, let alone guidance, on an Internet forum. You are going to need a very good electrician to achieve what you need.

You might like to study how 2 and 3 way lighting circuits are achieved. There are some diagrams here https://www.diynot.com/wiki/Electrics:Intermediate

 

[securespark]

One way would be to use Quinetic switches and receivers. I believe they have units that dim.

But you'd still need to get cables between floors to the light fittings.