Sheffield Crown Court was told how Dennis Pickerden ran a number of building companies across the region.
The 46-year-old developed a sophisticated scam to convince his victims to part with over a quarter of a million pounds in total over a period of nine years, between 2007 and 2016.
Prosecuting, Craig Hassall, explained how Pickerden approached potential customers by sending out unsolicited quotes, after accessing their contact details through successful planning applications for property extensions.
After Pickerden drew homeowners in with quotes deliberately priced significantly lower than his competitors, they were then provided with references, portfolios of work and even DVDs to convince them he was reliable and trustworthy.
Pickerden undertook a variety of projects including extensions, loft conversions and paving driveways. Work would get underway, but before long problems would arise, progress would slow, and clients would be asked to make further payments.
Eventually he would ensure that there was a major disagreement and walk off the job leaving work unfinished and often in a dangerous state.
In two cases, lethal faults were discovered in the shoddy extension work he had carried out before abandoning the job.
One victim targeted by Pickerden was a woman from Crowle, who he sent an unsolicited quote of £69,000 to build an extension at her property.
He asked for money to be paid in cash in installments, and the court was told how after telling the woman he had 'under-priced' the work she paid him an additional £8,000 above the quote he initially offered.
After Pickerden abandoned the extension work mid-way through, the woman had to spend an additional £70,000 for remedial work to be carried out.
The court was told how many of Pickerden's other victims lost their life savings and their homes.
Several were so distressed by their experiences they have been left with long-term health issues including depression and stress and two even considered committing suicide due to the financial and emotional impact of his offending.
In total, Pickerden, of Alexander Road, Cleethorpes pocketed around £700,000 from his victims, who paid £379,000 for remedial work to be carried out once Pickerden had abandoned work at their properties.
The dad-of-two pleaded guilty to fraudulent trading at an earlier hearing, and was today sentenced to six years and nine months in prison at Sheffield Crown Court.
Sentencing Pickerden, Recorder Fiona Davies told him he had in some cases deliberately targeted vulnerable people, including elderly homeowners and a couple who spent their life savings to commission an extension on their home for their daughter who had recently been diagnosed with multiple sclerosis.
She said: "This is a high impact case. There's agreed evidence of the serious detrimental effect this has had not only financially, but physically and psychologically.
"[Your] victims were particularly vulnerable."
Recorder Davies also banned Pickerden from being a company director for nine years and a proceeds of crime order was lodged.
Commenting after Pickerden was sentenced, Arslan Khan, Specialist Prosecutor in the CPS Specialist Fraud Division, said: “Dennis Pickerden started building projects with no intention of ever finishing them. The work his companies undertook was shoddy and often dangerous. He repeated the same fraud over and over again, deliberately abusing homeowners’ trust.
“His victims were left out of pocket. Some have lost their homes and others have serious health conditions that will need long-term treatment.
“Pickerden’s offending was carefully planned and so extensive that prosecutors were able to show that it amounted to serious fraud. I hope today’s sentence will provide some sense of justice to those whose lives he affected.”