Installers and certification: common questions

Not by law. But you will lose access to the grant schemes, and to being paid for electricity you export.

A buyer's solicitor will also ask for the certificate when you sell.

The company has been audited against a published standard, and can be audited again. It is not a guarantee that every job is good.

What it changes is that there is somebody with the power to make them put it right.

Not MCS itself. Independent certification bodies do the audits, and they in turn are accredited by UKAS, the national accreditation body.

So there are three layers: the installer, the body that audits them, and the body that accredits the auditor.

The company. It covers their quality management, their record keeping and the qualifications their people hold.

Worth checking when work is subcontracted: the certificate belongs to whoever registers the installation, and that has to be whoever did the work.

Look up the certificate number from the quotation in the MCS directory on their website.

Check two things: that it is current, and that it covers the technology being installed, since solar certification does not cover heat pumps.

That is what the insurance-backed guarantee is for. It is a separate policy from the workmanship warranty, and certified installers have to provide one.

Find the actual policy document before you need it. Many people assume they have this cover without ever seeing it.

The installer first, in writing. If that does not resolve it, there are two routes and they do different jobs.

The consumer code handles the contract, the selling and redress. The certification body handles the technical work. Your paperwork names both, so the second letter goes to whichever of them covers the problem.

Yes, and it is the most useful thing about the scheme. Anyone can read exactly what an installer has agreed to do, free, on the MCS website.

That means the calculations behind a quotation are checkable and do not have to be taken on trust. The guide on what certification covers explains how the documents are organised.

Get three quotes, and compare what is in them and not only the price. The one that surveyed your house properly will be obvious from the paperwork.

The guide on what a good quote looks like sets out what to expect, and there is a list of questions to ask before you sign.

No. Two certified installers can quote figures that differ substantially and both be complying fully.

What the standards constrain is the method behind the numbers, which is what makes two quotations comparable.