A Grade I listed medieval house and its world-famous garden have been earmarked for a £4 million grant from the Heritage Lottery Fund, it was announced today.

The backing from the Fund will support a £7 million project to preserve the timber-frame house and estate at Great Dixter, near Northiam, said the trust which runs the property.

The 57-acre estate was the home of 20th century gardener and writer Christopher Lloyd, who worked with his head gardener Fergus Garrett to plant the most "generous garden imaginable".

The Great Dixter Charitable Trust said the multi-million pound project aimed to make essential repairs to the historic buildings, which include one of the largest surviving medieval timber-framed halls.

It will also go towards preserving and displaying previously unseen family papers and photographs.

The Lloyd family first bought the estate in 1910 and established and maintained the gardens at Great Dixter.

Included in the family papers is correspondence between Mr Lloyd's father Nathaniel and architect Sir Edwin Lutyens who was commissioned to restore and enlarge the medieval home.

The funding will also help the trust, which was founded by Mr Lloyd before his death in 2006 to bring the entire estate under its ownership and develop its training of horticultural students.

Great Dixter has secured a 'stage one pass' from the Heritage Lottery Fund which means the money has been earmarked for the project. The trust can now progress to stage two, submitting a further fully developed application to secure the grant.

The trust is undertaking fundraising for the remaining £3 million it needs for the project.

Carole Souter, director of the Heritage Lottery Fund, said: "Great Dixter is one of England's most wonderful gardens and a permanent reminder of the vision of Christopher Lloyd.

"The estate is run by a dedicated team who are passionate about its legacy.

"The support of the Heritage Lottery Fund will help secure the future of this internationally important site, its collections and its contribution to the development and training of gardens and gardeners around the world."

Mr Garrett, who is chief executive of the Trust, said he was delighted with the funding.

"Christo left us a very special legacy and people love to come and be inspired.

"The Heritage Lottery Fund has given us a fantastic launch pad for our future plans. Now the hard work begins."