Try Premier Guarantees
http://www.planningportal.gov.uk/england/professionals/en/4000000001387.html
or LABC
http://www.labc.uk.com/site/scripts/documents_info.php?documentID=15&pageNumber=1

Posted By: Sally MI've read the discussions on Zurich and NHBC

Where? I need to see this. Martian, are these an alternative to the de facto (mortgage requirement) necessity to have NHBC Certification?

All of these are insurances and if you build properly you wont need or benefit from them. It is also notoriously difficult to get a claim through and they dont cover very much either. A normal home insurance policy covers more!

From what I can tell most of the problems people have with warranties is the limited cover they provide. Typically they seem to cover defects that are unavoidable such as unexpected subsidence but they tend to resist some claims for defects that are really build quality issues. For example I recall a case where someone had problems with the drains blocking every few months because too many bends were used. The drains appeard to meet the letter of the regs but not good practice. The insurer claimed there was no evidence the drains didn't work or had become faulty since construction.

So take out a policy to aid reselling but make sure you have a good builder!

Posted By: tonyif you build properly you wont need or benefit from them

That's been my approach - never had PI and only once feared a claim, due to arithmetical error in an Interim Certificate, which left the client out of pocket when the contractor went bust.

Would these insurance policies pay out, and then come after the architect if it was his negligence? Is it really an alternative to PI, or as Pete1951 and CWatters say, just a required wangle, alternative to the traditional NHBC one?

I have built under certificate from a Chartered Structural Engineer and I sold my house. However, not all lenders will accept the certification route because it relies upon the PI insurance of the engineer. That said, I have also sold a barn conversion with nothing at all, the issue was never even mentioned. If you are building to sell, you’d be mad to build without certification or warranty. I like certification because I trust proper engineers, though not architects.
Once a property has been occupied the requirement for a warranty changes - check the lender's handbooks on the CML website. A warranty vendor won't metion this though. If you need a mortgage to build, you need to speak to your lender quick, don't put a spade in the ground until you have.
Above, my opinions only. Five succesful self-builds, zero warranties.

Posted By: Paul in Montrealare you not registered?

Correct - I'm a B.SC.(Architecture), 'in Architecture', not 'an Architect'. A good friend of mine led the RIBA effort to uprate the status of Architects, back in the 80s. In the end, all that was achieved was a few bureaucratic measures, like making PI and CPD compulsory. Neither did anything to improve the abysmal standard of as-built 'architecture'. As ever, it's still a 10% lake of excellent architectural firms in a 90% ocean of mediocrity and a 40% sea of downright awfulness. CPD was the biggest failure of all - whereas Doctors and to an extent Solicitors depend absolutely on CPD to keep up to date, to Architects it's just repackaged trade presentations with wine, sandwiches and so many brownie-points towards the obligatory quota. The one and only effect on me of my friend's campaign was that I stopped getting my weekly free Building Design, then an excellent trade rag (unlike its present arty-farty online form). I spoke to the Publisher, said I'd been a career-long reader and contributor. He said sorry, we've agreed to only give it to 'proper' Architects - you'll have to pay if you want it. No other problems - PI is available to me at same price as to Architects, if I wanted it.