Bricks cracking

[thias]

I've noticed some cracking to our house's rear wall. It seems to start from around 50cm up and probably travels another 1.5m in a fairly continuous line.

Anyone know what this could be? I'm waiting for a local builder, that we've used in the past, to get back to me to arrange a time for him to come and take a look too.

 

[tony1851]

Pics from further back to give context would help.
But at first glance it looks as though the wall has been repointed in cement-rich mortar which shrinks and cracks.

 

[^woody^]

Thermal cracking.