An appeal for funds to restore parts of Agatha Christie's Greenway Estate in Devon is being launched.
Greenway was Agatha Christie's holiday home
The National Trust says more than £5m is needed to restore the estate, which is expected to be open in spring 2009.
Dame Agatha bought Greenway in 1938. Although she did not write any of her books there, it became a holiday home until her death in 1976.
The house was gifted to the trust in 2000 by Christie's daughter, Rosalind Hicks, and her husband, Anthony.
The National Trust has launched a £1m appeal to go towards the £5.4m needed to restore the house and open it to visitors.
The trust already has funds available from its acquisition of the property, bequests and a grant.
The result of a National Lottery bid for £800,000 in funding will also be announced this spring.
The trust plans to show the house's ground floor rooms and principal first floor rooms as they would have appeared in the 1950s.
Private family collections, including books and memorabilia about Agatha, would also go on show.