I am making an application for a new mains potable water connection with Scottish Water. It is for a small one bedroom cottage.

Scottish Water are asking me whether I want a "connection size of 25mm or 32mm or higher". They go on to say (typically) "if you are unsure, ask your contractor".

Now, apart from the question of "which contractor?" - groundworker maybe?  Can someone tell me the  pros and cons of choosing one size over the other? Is there perhaps an extra cost (to their already ridiculous fee of £1200 mostly for the administration work involved) to choosing the larger bore?

I assume that the smaller diameter will increase tap outlet velocity, or will it reduce reduce tap pressure?

Thanks,

Andrew

What distance is the pipe covering?

How far from the main to the house ..? And any non-standard things such as sprinklers required .?? 25mm would be fine for anything “standard”