The taxpayer will be hit with an annual bill of €800m for the next 25 years as part of a government agreement with private developers to build and maintain public buildings such as schools and hospitals.

A bill of €20bn will have to be paid if all the public-private partnership (PPP) projects go ahead as planned.

A senior department of finance official has admitted that the department has not yet evaluated the PPP projects already underway to see if they represent good value or whether the state would be better off doing the build itself.

Finance official Brendan Ellison told the Dáil public accounts committee last week: "It is something the department of finance is looking at in terms of whether there could be some mechanism to try and have a look-back review at some of the longer-established ones, but that has not really happened as yet".

On the cost to the taxpayer, Ellison said that based on contracts already signed and underway, the bill will be an average of €132m a year over 25 years.

If all the projects in the pipeline proceed to approval, the average annual payment will increase to €800m, he added.

But he said the government is reviewing its capital expenditure for the next
five years in light of this and will decide "over the next while" which projects will proceed or not.

The estimated cost of the PPP projects already signed include roads at over €1bn, the National Conference Centre in Dublin at €725m and the new Criminal Courts building at €600m.