They also need another 74,000 new recruits every year - to achieve only modest growth. Now the Construction Industry Training Board (CITB) has issued a "call to action" to the new Learning and Skills Council and warns that if swift action is not taken the skills shortage will reach crisis point.
The board has published a workforce development planning brief to help the LSC and other agencies understand the scale and urgency of the problem. Board chair Hugh Try will meet council chair Bryan Sanderson next week, in what will be one of the first meetings between the LSC and a national training organisation.
The construction sector - including carpenters, electricians, plumbers, bricklayers, managers and clerical workers - is a huge industry, involving one in 14 of the UK workforce. The majority of firms are small, with 90 per cent of companies employing up to 10 workers.
Peter Lobban, chief executive, said that in the past training and enterprise councils had had a narrow, local focus, and had not met the skills needs of the industry. Now the board was calling for a national approach from the council.
"Our biggest challenge is in qualifying the whole workforce. Large clients suchas the Highways Agency, the NHS, Railtrack, and local authorities have said they want all workers to be fully qualified and registered, before they come on site. It means that between 300,000 to half a million people have got to become qualified in the next two to three years.
"We have championed on-site assessment and training to help achieve this.
"It will be fantastic for the sector, creating a professional industry. It will be good for our image, and help end the cowboy image. We hope to interest the LSC in working together on this."
The training programme had to be extended through further education colleges and private training providers, he said. The industry also needed to widen its recruitment net, to bring in more women, and people from ethnic minorities.
Mr Try said: "We have great hopes that the Learning and Skills Council will take a wholly fresh, strategic approach to training at both a national and regional level. We're offering them the information, ideas and insight they need to help our industry recruit and upskill hundreds of thousands of people. We must develop our partnership with the council effectively, or else in a few years' time, not just the construction industry but the UK economy as a whole will suffer terribly from the results of severe skills shortages."