The landlord / agent has only just discovered that the balcony and outbuilding are unsafe.
What do you want to claim? You only have a potential claim if you have suffered loss? Have you suffered any loss?
Was your tenancy terminated correctly, I.e can the landlord give you two months notice?
As I say, you need to quantify your loss in order to claim. The balcony was not safe but you have suffered no injury. The outbuilding was constructed in inappropriate material but you have not suffered any loss as a result. As a tenant your only potential claim is with the landlord /agent if terminated in breach of terms of the tenancy.