White lime render craze cracks solutions?

[Hopefully24]

Hi all,
Our house is about two years old now, and have noticed hairline cracking patterns in our white lime render which appears to be crazing cracks. North facing walls around becoming green along cracks, so need a solution to fill or seal over the cracks, but still breathable etc.
Any advice welcome.

 

[Woods]

What kind of Lime? The wall looks damp (the green stuff). So I'm gonna guess it's hydraulic lime, which is not the right kind of lime to use on a wall above ground.