Alasdair Anderson:

The modern method is to have a loop circuit which takes the power to each light via the ceiling rose with a spur going to the wall switch to provide the switching capability. This arrangement requires additional connections and the ceiling rose is a sensible place to fit them. I therefore think that if you find out when the practice changed you will find when the ceiling roses changed.

I asked a building electrician some time ago who verbally informed me that the commonest arrangement of wiring ceiling lights in new build houses in the 1930s was a circuit which took the power from the consumer unit to each ceiling light in turn although radial wiring of lights was also used. The cables terminated in junction boxes inside the ceiling cavity with a cable to the switch and another cable to the light fitting. It requires a separate junction box and ceiling rose for each light fitting. This arrangement is still used today and is increasingly found in new builds because it is easier to change light fittings than if ceiling rose junction boxes are used as there is only one cable to the light fitting accessible from the room rather than three. Ceiling rose junction boxes became common in new installations around the time that lath and plaster ceilings were replaced with plasterboard.

Roy Bowdler:
My Fowlers Electrical Engineer’s Pocket Book 1946 (effectively pre-war) cites as its source of illustrations and wiring diagrams for lighting, AP Lundberg and Sons Ltd of London. The illustrations seems to show two pin sockets an plugs. Presumably allowing light fittings both on stands and ceiling suspended  to be moved around from room to room   

I'm well aware that bayonet cap plugs existed to enable portable appliances to be powered from the lampholder of a ceiling light back when wall sockets were scarce, but I have not seen two pin sockets on ceilings. In some old houses 2A wall sockets were installed that were connected to the lighting circuit.

Alasdair Anderson: 
BS 67:1969. Specification for ceiling roses.

However the BSI website also has the following earlier editions of the standard:
BS 67:1938. Specification for two and three-terminal ceiling roses.

I make a guess somewhere between 1938 and 1969. Notice that the 1938 specification mentions two and three terminal ceiling roses. The ceiling rose junction boxes I'm referring to in the OP consist of 3 + 3 + 2 terminals along with an earth terminal.


The loop wiring arrangement almost certainly predates the ceiling rose junction boxes as it was accomplished using a three terminal junction box with terminals for live, neutral, and switched live / power to the ceiling light. Earth was provided using a separate cable.