Advice on what room sets fit which wooden doll toy houses

[maruchan]

hello all
Can anyone advise?
Do most room sets that are sold like Le Toy Van/Pintoys etc - do they fit any wooden dolls house or is there some sort of scale that we need to look out for.

My mum in law bought a second hand dolls house (up in her loft) but can't tell me what brand or size. I have seen some room sets on e-bay going cheap but not sure if they fit? Please help. Many thanks.