I may have found a solution, this is not in anyway conclusive because it is only based on very short trial periods.
Previously I was setting up traps centrally within open areas in the garden to give the light good cover. Moths were obviously flying past the traps on their way to lit house windows.
Last night I tried situating a trap directly against the outside wall of the house and within five minutes the first moths were in the trap. I moved the trap on to each of the outside walls of the house with the same results and even on the wall with no lit window moths were falling in to the trap within five to ten minutes.
I hope to have time to use a trap once or twice a week over the next few weeks and will let you know if this continues to work.