If your application is successful, you will be assigned a dedicated contact from RetrofitWorks. They will be able to give you the name of any person that will visit your home and you can set a password they have to use when they arrive. Anyone working on the home will carry a photographic ID with them.
RetrofitWorks contractors always make appointments and will never arrive unannounced. They never work outside normal working hours (8am to 5pm Monday to Friday) without arranging with you first.
Do not allow any unexpected visitors to enter your home without checking with RetrofitWorks first.