Renovations at Anmer Hall, in Norfolk – Prince William and Kate's 10-bedroom country home – are nearing completion with the recent addition of a critical extension, as well as a new roof.
The home, 120 miles north of London, is a gift from William's grandmother Queen Elizabeth, with the costly renovations borne by the royal family.
Kate, meanwhile, has thrown herself into overseeing the last of the preparations since her recent return from New Zealand and Australia.
Vital work has been done on the so-called "garden room," 16'x16' glass-fronted room, with windows raised within the roof. On its parkland side, the couple will eventually erect a pergola, to allow enable the growth of vines or something similar to provide shade and privacy.
The new room spans a gap between the main house and some old wood stores, which are to be converted into rooms, including kitchen and lounge and bedroom. It has been suggested that this will be for nanny Maria Borrallo.
Already, the vast Georgian mansion has an outdoor swimming pool and tennis court, and is surrounded by acres of parkland of the Queen's Sandringham estate – just perfect for raising children away from the hubbub of William and Kate's Apartment 1a at Kensington Palace.
"It's like a fancy farmhouse," someone familiar with the house tells PEOPLE. "It isn't grandiose. But it's a great, friendly family environment."
The new room is designed by one of Prince Charles's favorite architects, Charles Morris, and Kate is also said to have enlisted high-end designer Ben Pentreath.
Before the tour Down Under, she stepped up browsing for interiors. At Knights Oriental Rugs in Henley-on-Thames, she picked out some rugs.
"She wants to put her own influence on [Anmer] because," owner Simon Knight told PEOPLE, "she wants it to be her own family home."
With reporting by MONIQUE JESSEN