This is one of my recent demos in a class (20/9/23) This was a pen and ink and watercolour of an old derelict building in South wales.  I have already  created smaller versions of this scene, in graphite and also in a journal form  with ink and washes of colour.  It is the looking and placing the angles and perspective of windows that was tricky for this one.  I hope the students have fun with this one.