We definitely didn't want to go down the ashp route but it's impossible to pass the SAP calculation for energy performance if you don't put one in.
We were going to fit the very best german boiler, they're mega, we've fitted one before, but it was an instant fail in the SAP, if we chose to fit any ashp, the cheapest, nastiest, least efficient one imaginable, it was a straight pass.........🤷🏻‍♂️
This is how the figures are manipulated to make you have on in a new build.
We've also fot to have 140mm of celotex in the cavity, it's huge......... but hopefully it'll be warm......🤷🏻‍♂️

As far as I know.....noisy ashp's are often down to them not been installed perfectly plumb. If they're slightly out of plumb the fan is running at an angle and the bearings get hot, noisy and wear out........