I currently use the RLA AST for all my properties. However, after some recent tenant problems I would like to add some additional clauses to the agreement. e.g. Rubbish must not be allowed to build up in the gardens and must be put out for the local refuse collection service every week. The oven must be run through it's self clean program every week. If at the end of the tenancy the property is not cleaned to the satisfaction of the landlord then the landlord can arrange for a professional cleaning company to clean the property to be paid for by the tenant in full.
Can you advise me if I can put in any clause and if the tenant signs and therefore agrees to these, are they legally binding?