RENOVATION works on the Leinster House complex cost more than €1m last year, the Office of Public Works (OPW) has said.

The projects, mainly work to restore the crumbling structure of the 18th century residence and improve fire safety and wheelchair access, were necessary to keep the historic building safe.

The OPW has also said that a much larger renovation project will inevitably be necessary as the condition of Leinster House continues to deteriorate due to age.

The restoration of the controversial Leinster Lawn, which had been used for car parking, ended up costing the taxpayer just €39,279.

Full-time staff with the OPW who ordinarily carry out flood-relief work were asked to assist in the project to keep costs down.

"The works... consist of the following: removal of 68 car-parking spaces, tarmac, hardstanding and kerbs, [then] finished with topsoil and grass," said the OPW.

Two other major projects also took place last year, with the first costing €395,887 and the second coming in at €476,642.

The first project saw a roof above the Seanad chamber strengthened to ensure that it could not collapse, said John Cahill of the OPW on a tour of the sites with the Sunday Tribune.

The work involved "structural strengthening to roof trusses in the attic [and] new steel trusses to be fitted alongside two existing timber roof trusses to provide support to the suspended floor below".

The OPW said it also had to remove debris, carry out other strengthening works and form fire breaks to ensure that any blaze in the building could be contained.

A second project to improve wheelchair access and also fit out a new basement archive ended up costing €476,642.

The work included the provision of a ramp to the iconic plinth at the front of Leinster House to allow all visitors access to that area.

A major archive project was also undertaken in the basement of the complex to allow storage of thousands of documents, some hundreds of years old.

Included in the records are some of the oldest existing Ordnance Survey maps in the country and the original copies of parliamentary debates going back in some case centuries.

A so-called "hot desk" area for journalists was also installed at a cost of €39,279. Members of the media had been evicted from their traditional home on the first floor of Leinster House due to fears over the collapse of ceilings and floors.

However, after being moved to alternative premises at nearby Molesworth Street, journalists often found themselves locked out of the Houses of the Oireachtas because of the ever-increasing frequency of protests at the main gate.

A fourth renovation project, primarily related to fire safety, had been carried out at negligible cost by staff already employed by the state.

The OPW said the fire upgrades were amongst the most critical of works because of the massive burden of running a modern parliament in an historic building that had not been rewired since the 1960s.