Hi Neil

You seemed to me to be suggesting that there is no choice, and your criterion for the decision although available suggests that no one competent would not fit them. I do not believe this was ever the intention of the way the regulation is worded. I am sure that your designs have financial constraints, as they all do, and the arbitrator for that has to be the client. You may of course always decline the work, but this is not a realistic choice is it? If only all design budgets could be set by the designer! Here we are talking about a lot of money on any reasonably large design, and a fearful amount for a domestic, probably 50% extra. Serious justification is required.

There is a choice and cost does come in to it.  It all forms part of a designers risk assessment and there are not many installations I would suggest AFDDs are installed outside of the 'shall' requirements of BS 7671.  There are some though but every installation I will look at based in its merit and engineering judgement, which does include cost, but not solely.

There is a choice and cost does come in to it.  It all forms part of a designers risk assessment and there are not many installations I would suggest AFDDs are installed outside of the 'shall' requirements of BS 7671.  There are some though but every installation I will look at based in its merit and engineering judgement, which does include cost, but not solely.