@prjohn The council place all responsibility on me, my sound meter app on my phone was dismissed as not calibrated and a full sound survey was mentioned - a quote was £1100

Specifically, the proposal would operate at 7.5 dB(A) above the prescribed MCS (Permitted Development) level of 42dbA.

That is a very, very low bar indeed when it comes to rated noise for ASHPs. Not sure how many ASHPs there are out there that are actually rated by manufacturers to operate at 42dB. Our pump runs at about 65dB and I can't imagine it annoying our neighbours. As @witchcraft says, it's not running full tilt all the time. 

And then noise is so subjective. In our latest interview with @grahamh (Graham Hendra) he says that he has two heat pumps with the same dB ratings, yet one sounds louder than the other:

In our case, our heat pump is much quieter than the electric pump that feeds air into our home sewage treatment plant, yet that would be approved and not be a planning issue. 

I will ask around for some advice.

@kev-m The ASHP failed the MCS calcs by 7db - see the Planning Officers points,  therefore the EHO says no chance - and nothing so far- my own app Sound meter of the current oil boiler exhaust and the ASHPs in the street already (Global Energy) fail to sway the discussion

@editor Staffordshire Moorlands

Just to check I am not getting confuddled (totally possible at this time on a Friday!) but when you are saying MCS, we are still talking about MCS who certify ASHPs and installers right?

Reason I ask is that on the MCS site a whole list of Vaillant Arotherm pumps are listed as MCS certified, so not sure how they can be both certified AND fail their calcs? Again without knowing exactly which model I am guessing, but the closest I can find to 15KW is the aroTHERM VWL 155/2 A 230V, which is showing as having current MCS certification.

@dchilton Hi i tried to attache the PDF file of the calculations/form that the installer filled in - but no luck - the ASHP falls outside of the Permitted Development - please see note from Planning Officer in the thread, thanks

Pretty sure planning have found the wrong ASHP - There are plenty certified on the MCS website. I'd advise you find the specific model and download its compliance certificate. They may have found the wrong one 

https://mcscertified.com/product-directory/

It literally says on their website they are MCS certified

• The aroTHERM is Certified by the Microgeneration Certification Scheme (MCS), a national quality assurance scheme that recognises high standards in renewable energy technologies.
• As an MCS certified product the aroTHERM, you could benefit from Renewable Heat Incentive (RHI) payments.

https://www.vaillant.co.uk/homeowners/products/the-arotherm-air-to-water-heat-pump-1408.html

Just had a reply from an installer this query and they asked: “020 says 42db at neighbour’s nearest point, not sound output of heat pump at point of operation. Has the 020 been done and done right?”

@mbcool, how far will be your heat pump be located from your neighbour?

Here’s a cheeky suggestion from another experienced installer: “Put a wooden cover over it, then you can't see it. It's no quieter but according to mis020 it is. So no planning required.”

@editor 7m from neighbours bedroom window - but not directed at it. the bedroom window faces in a parallel direction and is set back - If I could download the PDF MCS calcucaltion it would be clearer. The file is too large for the forum

@batalto Planning are objecting to the calculated noise level at the neighbours - calculation done by the insatller

Posted by: @mbcool

@editor 7m from neighbours bedroom window - but not directed at it. the bedroom window faces in a parallel direction and is set back - If I could download the PDF MCS calcucaltion it would be clearer. The file is too large for the forum

Maybe upload a snapshot of it? (snipping tool or similar?)