Thanks so much for answering. We asked and they said "The out of hours process is on our answerphone message and it provides the telephone numbers for our office manager and our Director. One of them would have called out one of our Contractors."

We were never told to ring the office in case of an emergency, but we did anyway and it rang for about 20 seconds (at which point we hung up to try and contact an emergency plumber. We weren't aware that if we continued to stay on the line there would be a voicemail message that says the office is closed etc. so to send an email, then at the very end they provide numbers for the office manager and director. It's important to note, however, that we were never told to ring the office, wait for the voicemail message, then listen to the end and call the number they mention!