A building comprises at least two vertical columns of modules wherein in each column the modules are substantially identical to one another, the columns cooperating with each other to define a vertically extending void having a light source at one end, the modules in at least one of the columns having a light admitting section adjacent said void for admitting light from said light source into the corresponding module. The light well produced thereby allows more light into the rooms. The same principle can be applied to conventionally constructed buildings.
