Construction could be buffeted big-time if there's a "hard Brexit" and lose more than 200,000 workers.
According to a report by design and consultancy firm Arcadis, the industry could suffer from a "skills gulf" once the UK leaves the European Union and the loss of nearly 215,000 workers from house building and infrastructure if there's a hard Brexit.
For example, if the points-based system that's currently in place for non-EU migrants is extended, that will see the number of EU construction workers entering the UK fall at the rate of attrition, meaning the EU nationals leaving the industry won't be replaced at the same rate by new EU workers.
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If that plays out, Arcadis, says around 214,000 fewer people from the EU would enter the infrastructure and house building sectors between now and 2020, assuming the trigger date of Article 50 falls in March 2017 as Theresa May has said.
And even a soft Brexit could see the sector lose 135,000 workers, which might then have a knock-on impact on the number of homes and transport networks being built or maintained.
The report notes that, unlike the financial services industry for example, construction is hugely reliant on unskilled or semi-skilled workers. If a points-based system were to be introduced, it will be problematic for ensuring the required labour is brought in from overseas.
James Bryce, Arcadis' director of workforce planning, said: "What started as a skills gap could soon become a skills gulf. The British construction sector has been built on overseas labour for generations, and restrictions of any sort – be it hard or soft Brexit – will hit the industry."
If the UK misses out on so many workers Bryce predicts rising costs for businesses and "transport networks being delayed".
The president of the SMMT has also warned that leaving the Single Market could jack up prices, with the car industry weathering "billions" in tariffs should Britain not sign a deal keeping it within a tariff-free trading bloc.