Speaking on 2012 ITV documentary The Royal Restoration about the project, Annabel revealed that Prince Charles has incredible attention to detail.
“He will look at everything. His eye for detail is quite extraordinary.
“I don’t think I’ve ever worked with anybody who is so interested in the detail.”
She added: “He always likes to be completely involved and know what’s being suggested.
“He’s looking at every piece of material – ‘What’s this for? Is that for a chair?’ Where’s that sourced from? Has it got nylon in it?'
When Charles was questioned on the documentary over where he learnt to pay attention to details, he told how he'd learnt it from his grandmother, the Queen Mother.
While he naturally paid attention to details, she encouraged the ability and would point things out herself, he explained.
Charles is known for his interests in sustainability, as well as the way things "look".
At his Clarence House home, half of the Prince's office and domestic energy use comes from renewable sources such as woodchip boilers, air-source heat pumps, and “green” electricity - after he installed solar panels on the roof.