the roof, which is 20 times the size of the average British family's home, was made possible by the erection of an extensive free-standing scaffold roof structure. At the height of the restoration works, of scaffolding tubes covered the building's entire exterior. This allowed repairs and restoration to take place over 18 months, including the final restoration of the original bold red and black tiled geometric diaper pattern. The entire property was rewired with special cabling, copper sheathed (fire and rodent proofed). Much of the original lead piping was replaced and a fireproofing scheme, mainly through the design of a suitable compartmentation system was designed and implemented. Interior scaffolding was installed in the high hallway to repair the lantern rooflight, and to provide access to other high points of the interior. These initial works cost more than £10 million, much of which was raised through donations via the "Save Tyntesfield" campaign and the sale of lottery tickets to visitors. The Trust had been reluctant to allow visitors to the house while work was underway, especially taking into account the costs of Health and Safety requirements and the delays these could cause to the essential preservation works. But the need for cash dictated the answer, and the Trust learnt that, through giving the public close access to the preservation works, they actually gave more additional donations as a result of seeing where their money was going and how they were making a difference. Estate House interior Principal rooms include the Library, Drawing Room, Billiard Room, Dining Room and Chapel. During restoration, the National Trust, for the first time, allowed visitors to become involved in the restoration process and "witness the challenge of bringing Tyntesfield back to life." The Library is regarded as the most important gentleman's library in the possession of the Trust. The carpet and some of the furnishings in the Library were designed by Crace, whilst the book collection is the most extensive Victorian library collection owned by the Trust. The centre of the house is occupied by the hallway and staircase, which show the greatest number of changes since the original design. Once the Trust took ownership, scaffolding was placed in the hallway to repair the roof lantern. While this was in place the architectural paint analyst Lisa Oestreicher was able to examine the decorative scheme that had been used in the spaces and room frequented by the