We can reveal that Hertfordshire County Council is chasing contractors for payments that could exceed tens of thousands of taxpayer-funded money, after a Freedom of Information request was made by this newspaper.

Over the last two years, the Hertfordshire Home Improvement Agency – a branch of Herts County Council offering specialist home improvement works – has paid more than £4.2 million to contractors and completed 624 projects for its clients.

But, HCC is currently fighting to retrieve two instances of payments that were given to approved contractors. The exact total of these payments was not disclosed.

In both cases, the council did confirm that the contractors’ workmanship “did not meet current building standards and regulations”.

So how are these contractors vetted and then paid?

In order to be considered for the HHIA contractors list, a firm must provide information on their insurance cover, trade body accreditations and health and safety. Any prospective contractor must also provide three references.

Funding for these works can come from a Disabled Facilities Grant – which is a capital grant provided by central government from its Integrated and Better Care fund, funded by NHS England, and then distributed and administered by a council.

The contract for works is agreed upon between the client and the contractors – once a Disabled Facilities Grant is awarded.

According to one source familiar with the process, contractors can be handed significant sums in the form of ‘interim payments’ – sometimes in excess of £10,000 – months before works are completed.

We spoke with one Hertfordshire resident, who does not wish to be named, who is attempting to retrieve more than £15,000 that was paid to a contractor who then performed sub-standard work on their property. Herts County Council refused to confirm this figure.

According to reports seen by this newspaper, the HHIA had repeatedly warned contractors working on that property that their work had not been up to standard.

One report dated in January states the workmen’s materials were not cleared away, mud was left on the carpets and dust was gathering inside the house which caused residents severe difficulties breathing.

In a damning comment, the report states that the “workmanship has not been up standard of a competent building firm”.

A HHIA spokeswoman confirmed: “Of the hundreds of disability improvement projects delivered by the Herts Home Improvement Agency over the last two years, two projects regrettably fell short of the high standards we expect from our building contractors.

“The agency carries out its own inspections on works, in addition to inspections by Building Control, to ensure the work meets with the required standards.

“In both of these cases, phased inspections were carried out by the Herts Home Improvement Agency and Building Control.

“Not all of the work was deemed as substandard and some elements were signed off. However, subsequent work did not meet with the high standards we expect for our clients and the contractor was removed from the work.

“The agency has worked with the residents concerned throughout the process and appointed new contractors to complete the works. Hertfordshire County Council is taking the necessary action against the contractors involved.”