Sash UK - which was started by local joiners Ron Bean and Terry Morrell in 1965 - was sold to new owners in 2016.
Nick Lilburn and John Ross, who were directors for Safestyle UK, took over the Ferrymoor Way firm which employed a 200-strong workforce and had a £22m turnover.
However, subsequent financial difficulties plunged the long-running firm’s future into doubt and it entered administration last June.
Bosses were accused of disobeying workers’ rights laws which permit employers to consult employees and keep them informed when facing potential closure.
A total of 103 people sought damages - referred to as ‘protective awards’ in documents obtained by the Chronicle - against Sash UK which will see them receive 90 days’ wages.
Whistleblowing ex-employees told the Chronicle staff were given ‘little warning’ over the firm’s plight.
One, who wished to remain anonymous, said: “The way it was handled was appalling - staff, some who were long-serving, were thrown out on their ears with little warning.
“It was a fantastic firm to work for beforehand and was a real labour of love for Ron and Terry.
“It’s sad it went downhill thereafter and it all ended this way, but staff felt incredibly let down and thankfully we’ll now get what we deserve.”
Ron and Terry, who met at Cudworth Secondary Modern School, set up Sash UK in 1965 after being inspired into the industry by their woodwork teacher.
After working on building sites during the day, the pair were making windows, door frames and other items such as skirting boards and architraves in the latter’s garage after work which led them to form the company, then known as Bean and Morrell.
In 1972, they bought St Patrick’s - a derelict church in Grimethorpe which had been closed for some time - and established a joinery shop but ended up moving to the purpose-built 112,000sq ft warehouse on Ferrymoor Way which allowed them to manufacture in excess of 2,500 windows per week.
The tribunal documents said: “Joint administrators of the respondent (Sash UK) have indicated to the representative of the claimants that they do not intend to contest the claims for a protective award.
“The respondent failed to comply with the requirements of section 188 and 188A of the Trade Union and Labour Relations (Consolidation) Act 1992.
“It is declared that the claims for protective awards are well-founded.
“A protective award is made in respect of the claimants who were employed by the respondent at their premises at Ferrymoor Way, Grimethorpe, and who were dismissed as redundant on June 12, 2020.( “This is for a period of 90 days because of the complete failure to comply with the statutory requirements for consultation.”
Barnsley East MP Stephanie Peacock said the closure had had a devastating impact on the local area, one already one of the worst-off areas in the borough.
“Sash were a major employer in Grimethorpe before they entered administration with over 100 employees based at their site,” she added.
“The loss of work has had a devastating effect on our community in already challenging times.
“I welcome the result from the employment tribunal and am pleased to see that all former employees are to be given the compensation that they rightly deserve.”