THE first house in the world to be lit by hydro electricity will close for 18 months for electrical rewiring.

Cragside, the home of 19th Century Tyneside industrialist and inventor Lord Armstrong, will have its first complete electrical rewiring for 60 years in the £1.5m renovation scheme.

It will also have a heating system installed to provide the ideal environment for its treasures.

The house is at the centre of a 1,000-acre estate run by the National Trust on the edge of Rothbury, in Northumberland, and the past two years have seen record-breaking visitor numbers of more than 160,000 annually.

Property manager John O'Brien said: "When everything is finished, it will put Cragside in a different league in terms of enjoyment.

"Closing down the house is a big blow. It is going to be a loss, but the estate and gardens will still be open and we are planning attractions to counter-balance the house closure."

They will include the creation of a sculpture trail through the estate by North-East artists, based on a theme of Lord Armstrong's vision for Cragside.

It was the first house in the world to be lit by hydro electricity and is believed to be the first to use modern incandescent bulbs invented by Armstrong's friend Joseph Swan, who was born in Sunderland.

The refurbishment is part of £6m-worth of improvements to the estate, which will continue until 2009. The house will close in September and will open in April 2007.