render repair

Hi, hoping for some help. Been let down by a few tradesmen already. We have plaster crumbling around a kitchen window. Think it's due to water ingress from blocked gutter outside. Reckon it needs stripped off, sealed and replastered. Also small part of front wall below window is damp to touch...

My house's render needed a repair (it was falling off at the top), so I got 3 quotes for replacing, effectively, the top 1.5m of render across the top of the front wall. The scaffold has just come down and it looks like this. The builder says that it need another coat of paint (it has 2 coats...