After 1 year refurbishing my house in the evening and weekends without any holiday, dinner out... I just discovered a cracked window lintel 2 smalls cracks in the external insulation all the way to the windows upstairs. We were at the point of skimming walls downstairs and choosing kitchen. Now everything on hold and quite worry. I have an ex-council house with walls made out no-fine concrete. Yes, I know... The window in the living room is quite large, 2400mm wide, the window above (bedroom) is 1800x1200mm. The little crack under the window upstairs appeared a few weeks after skimming (6months ago). The cracks outside in the insulation are hair thin and could have been there for a while but I realised today. I have no idea how bad this is. I need your knowledge and experience now more than ever. I would appreciate all your advise to help me with this.