The BBC has been criticised in a report by the National Audit Office for overspending on three construction projects costing £2bn in total.
The projects include the redevelopment of the BBC's London headquarters, Broadcasting House, which is over four years behind schedule and £55m over budget, according to the NAO.
The project was supposed to cost £991m and be finished by December 2008. It is now expected to cost £1.05bn and not be ready until April 2013.
The NAO accused the corporation of poor management on the scheme and said that the first phase of the project “got into serious difficulties before the BBC took action”.
The report added: “The full scope of the project was not defined clearly at the outset, and weak governance and poor change control processes contributed to severe delays and increased costs.”
The NAO also highlighted problems with the BBC's Scottish headquarters at Pacific Quay in Glasgow. Expected to cost £126m and be completed by June 2006, it was a year late and £62m over budget.
However, the BBC’s Media City development in Salford is forecast to come in £76m cheaper than the budgeted £877m.
The report added: “The BBC is not well placed to demonstrate value for money from the £2bn it has committed to spending on the three projects over their life. The absence of clear assessments of intended benefits at the outset means there is no baseline against which to measure achievements.
“For future major projects, the BBC needs to make sure that investment decisions are based on a full assessment of the scope and cost of the project; there are clear baselines so that performance can be measured and project teams held to account; and proposals submitted by management are reliable and subject to effective challenge by the BBC Trust.”