I spoke to another local plumber.  He said it usually takes him 10 minutes to do a PS3 and send it in using the form which can be downloaded from the council web site, or 15 minutes if he wrote his own.  He doesn't charge extra if it was "a job worth a few thousand".

How does that seem to other plumbers?

Thanks Jaxcat. Your comments are appreciated while I try to get a feel for where I should go with this.  Yes, as mentioned at the beginning the plumbing was a quoted job ... $23,000-odd full house job for which the progress and final payments were made on time as due.  I am a person of principle and have no problem paying on time for an honest bill for an honest job.

Following your point about the responsibility taken when signing a PS3 and working the PS3 'cost' into a quote, were PS3's often required in 2010?  But it really does not excuse what he is obviously trying to do, get me to pay for his mistake on top of what I do feel obliged to pay for (spout/mixer job and a reasonable sum for a PS3 so long after the job).

The other thing with the PS3 is ... he did not sign and date it ... so in that case it is really worthless?  What are the repercussions?  Even though the council pointed out that it was not signed and dated, they didn't pursue it and issued the CCC anyway.  The whole thing is quite bazaar but I understand a PS3 is not a requirement in the building code, just a discretionary mechanism for the council to accept that a job has been done to code.  Have I missed something?

Citizen's Advice on the second visit said to pay what I felt was fair with an explanation, and let the plumber decide if he wants to pursue it further.

At this point I am thinking that if the PS3 has any real value(?), to ask him to send me a signed and dated copy of the PS3 which I will ensure goes on our property file at the council, and in return I will undertake to pay the bill promptly ...

Councils are asking for more and more forms these days - in essence they are trying to shift the responsibility from themselves for checking the work to the tradesman who did the work.  Of course the tradesman who did the work is responsible, but the council who sign it off also have responsibilities.  PS3's and PS4's (commercial versions of the same thing) are really not worth a cup of cold sick legally - as the Council have pointed out they are not required under the building code and the Council have issued the code of compliance.   They will have all the plumbers details on the Building Consent, including his registration number etc - so I wouldn't fret about the PS3 not being signed or dated.  You could make a note on your copy of the date it was received.  Councils are requiring these more and more, but depending on the Council I would say in 2010 it wasn't common - at least in Wellington.  As Integrated says different councils in different regions require different things.

Again I would talk to your plumber about the bill - tell him you think that the charge for the taps is reasonable, but you are concerned about the charge for the PS3 when the account changed after you queried the remedial work.  Most tradespeople are pretty reasonable, and obviously you have had a good relationship in the past given he did a house lot of work and you paid on time. 

The PS3 says virtually "I did this, at this property, and I did it properly to the best of my knowledge."   Gasfitters have gas certificates that they issue about a job, but plumbers do not self certify as the Council check off their work - the PS3 and PS4 in my mind (and this is just my own opinion) is a version of getting plumbers to sign off their work and alleviate some responsibility from the Council.

I do not know if these Producers Statements (PS3's or PS4's) have been tested in court. 

Again, I urge you to discuss the matter with your plumber before trading letters - CAB are giving advice and perhaps with some legal basis, but nothing beats talking it through.   After all you may want this plumber back at your house to do a job in the future - he knows where everything is and you obviously liked his work if you got him to do such a big job.

Hi Justme - I think that is a very fair outcome on your part.  Sometimes the art of finesse and customer service gets lots along the way with us.  If we can visualise someone as a life long customer and not just one job along the way we would all be better off.  I try really hard to see things from a customer's perspective - and how I would look at it if the boot was on the other foot.   If you do this you can usually work through any issues.

If you have been this reasonable and the tradie doesn't front with a signed PS3 then he is making a bit of a mistake.  Word of mouth is the lifeblood of tradesmen and women.  You get so much more business through word of mouth (and presumably you can lose it this way too).  I would imagine this is especially so in rural areas.

Good luck with the rest of your project.