Builders are warning that the construction industry downturn will extend into 2010, as orders plummet and the collapse in housebuilding extends into the industrial and commercial sectors.

The private housebuilding slump, where the number of new homes under construction is at its lowest level since 1945, is set to continue next year when sharp falls in office and retail developments will add to the gloom, according to an industry survey.

Growing worries about the health of the sector are reflected in other key manufacturing areas with carmakers cutting sales and production forecasts and Corus, Britain’s biggest steelmaker, slashing output by 30%.

The manufacturing gloom is extending to small and medium businesses where companies are cutting staff for the first time in 18 months, says the CBI employers’ organisation.

Daily Telegraph