In 2003, plans were prepared for what the Duchy described as a "rural regeneration project", involving the restoration of three groups of buildings at Home Farm, Grange Farm, and Harewood Park itself, at an estimated cost of £8-9 million. The architect is Craig Hamilton. Home Farm and Grange Farm are intended to be developed as cottages and workshops. Overall, the intention is to undertake restoration on the basis of principles of environmental sustainability, and including the use of local sandstone from a reopened local quarry, and locally sourced timber. New woodland was to be planted, and schemes were included to retain water run-off and filter sewage in reed filtration beds. Prince Charles is reportedly personally involved in details of the scheme. The Duchy's website states:When complete the project will consist of a replacement principal dwelling as a focal point of the estate, the restoration of a Grade II listed stable block and former chapel together with the sympathetic rebuilding of eight additional dwellings linked with more than of high quality offices offering a combination of residential and workplace facilities for up to 100 people. The new house will be built on the site of the historic house. Three possible designs have been drawn up for the replacement house, for which outline planning consent was granted by Herefordshire Council in 2007. The agreed proposal is for a six-bedroom house, considerably scaled down from the original designs put forward in 2004. The proposed design is intended to echo that of existing stable blocks on the site, with arches influenced by the designs of Sir John Soane. According to Hamilton:Three designs have been prepared for the site and two of these have received planning consent. The first design refers to the work of Schinkel in Potsdam. The second is a synthesis of Greek and Roman references. The third design has developed out of the triumphal arch motif which is repeated in the design of the surviving early 19th century stables on the site. The new house is to be built out of local sandstone quarried on the Estate. In 2016 the walled garden and former fishing lake were restored. The Duchy of Cornwall denied that the new house would be the home of any member of the royal family, although there was local and national speculation that the house will become the main residence of Prince William and Catherine, Duchess of Cambridge. This speculation has died after Anmer Hall on the Sandringham estate was named in April 2013 as the official country residence of their royal highnesses when the current lease expired.