A SIX year plan to repair and protect the historic building of Castle Drogo near Chagford, expected to cost about £10 million, will hopefully be given the go ahead in May, say its owners.

The 'last castle to be built in England', set above the Teign Gorge and designed by leading British architect Sir Edwin Lutyens, was completed in 1930 after being commissioned by successful businessman Julius Drew.

However, it is now is a serious state of disrepair due to weather damage not helped by its exposed position overlooking the Dartmoor National Park.

The damp is exacerbated by leakage of water through its huge roof, which also has had a harmful effect on walls and windows.

But its owners, the National Trust, say if the project gets the go-ahead it intends to divide the repair work into three stages of two years each.

David Bailey, Castle Drogo's property manager, told the Times: 'We hope the work will start in about a year's time, January 2011, but we don't take decisions like this lightly and continue to review within the National Trust where our precious resources are best used.

'Therefore we will find out by May if we have the resources in place to begin the next phase of this important work.'

The National Trust, which took over ownership of Castle Drogo at Drewsteignton in 1974, is looking for sources of funding from English Heritage and the Lottery — but has not ruled out holding a public appeal to help raise the considerable sum needed.

Funds have been raised by selling off sections of the roof and recent publicity has already led to supporters of the building offering private donations.

The scale of the work is major, with a staggering 13,033 window panes — methodically counted no less, by a volunteer — in a building with 188 windows. The panes all have to be resealed in their lead frames.

This would follow on from a first phase in 2006-07 which was very successful in preventing water into the Castle Chapel.

Mr Bailey said that the trust has also to re-point the whole of the castle, fit a new waterproof membrane across the whole roof structure as well as some important remedial works which it will do at the same time.

Each phase will have a huge scaffold covering a third of the castle.

He added: 'Castle Drogo is one of the most important 20th century buildings and is of national importance and is Grade I Listed.

'The National Trust intends to spread the work over a number of years to ensure we can build the cost of this project into the rest of our important works.

'At the end of the project we will secure the future of this building for hundreds of years to come and it can be enjoyed by future generations.'

The trust says future work it will not affect the castle opening hours.

The castle, gardens and the grounds of the estate will remain open throughout the projected works and there will even be access to areas never previously opened up to the public.

The conservation work is planned to be completed by 2016.