A freedom of information request to the Department of Work and Pensions by Unite revealed official estimates show that 797,000 employees in the construction sector are paying into a pension of any form.
This is from a total construction workforce of around 2.2m divided between 1.5m employees and 700,000 self-employed workers according to Office for National Statistics figures.
It means just 36% of the construction workforce is known to be paying into a pension.
The percentage of site workers contributing to a pension is expected to be considerably lower and the number of self-employed workers paying into a pension is likely to be very low.
Unite national officer for construction Jerry Swain said: “These figures are deeply troubling. With the majority of construction workers not saving for retirement, we are creating a destitute generation of future pensioners.
“The way that construction is organised, with short-term engagements, rampant bogus self-employment and nefarious schemes such as umbrella companies, it is incredibly difficult for construction workers to have confidence in their continued employment so as to allow them to consistently pay into a pension scheme.
“The government needs to take urgent action to begin plugging this black hole in construction pension saving, the consequences of not doing so do not bear thinking about.
“After a lifetime of hard manual work the ultimate ignominy for construction workers is to face poverty in retirement. Put simply, construction workers deserve better.”