gable end problem?

[alfienumeric]

Back in 1970 we bought our present house(an end terrace property built in 1911)after a complete renovation which included installing a window(5ftx3ft) into the gable end wall,we moved in.A few years ago a crack appeared under the window which has broken 2 bricks,the crack which is approx 3mm wide appears again at the top R/H corner of the window appatuer and continues, following the motar joints,diagonally to the edge of the gable wall.There is also a small crack in the plaster behind the radiator under the same window in the dinning room of our property.
Can anyone advise me on this problem?

 

[ajrobb]

Did you put in a loft conversion as well? I'm thinking that extra load on the foundations might cause further settling.

 

[^woody^]

Not without any images.

Cracks in this location can be either normal expansion/contraction - normally the inner or outer wall and not both

or some rotation (ie movement) of the foundations at front or rear - cracks both in inside and outside and in same place

Other possibilities but these are the main two