Harry and Meghan are set to become William and Kate's neighbours at Kensington Palace after their wedding, and it seems that preparations started for the big move as early as last November.

As the world's media gathered on one side of Kensington Palace late last year for Harry and Meghan's engagement announcement, apparently work had already begun on Meghan and Harry's future home - Apartment 1.

"He keeps popping round and asking when it will be ready. He seems in a real hurry to move in with Meghan," a source says.

The Daily Mail reports Meghan has persuaded Harry to give up smoking and cut down on alcohol in the hope of starting a family after their wedding, meaning that they may need a larger home than their two-bedroom cottage sooner rather than later.

Apartment 1 and 1A. Photo / Getty Images
Apartment 1 and 1A. Photo / Getty Images

Royal courtiers were last year keen to let it be known that the couple would immediately be living at Nottingham Cottage - Harry's "bachelor pad" in the grounds of Kensington Palace - for the foreseeable future.

But insiders have known for some time that Harry always intended to move out of the cosy two-bed "Nott Cott" as soon as possible and into Apartment 1 - a stunning 21-room wing of the palace.

Soon after their engagement, the Queen's cousin Richard, the Duke of Gloucester, 73, whose three children are now grown up, offered to leave the splendid apartment so Harry and Meghan could have it.

The Gloucesters will move into the smaller but very comfortable apartment soon to be vacated by the Queen's private secretary, Sir Christopher Geidt, which neighbours 20-room Apartment 1A, which Harry's brother Prince William and his growing family live in.

A rare look inside apartment 1A where Kate and William live. Photo / Getty Images
A rare look inside apartment 1A where Kate and William live. Photo / Getty Images

William and Kate also lived at Nottingham Cottage before they started a family - it almost seems like a rite of passage for the royal brothers.

Several years ago a royal spokesman said that Harry had set his sights on grander accommodation at Kensington Palace but refused to confirm which apartment it was, other than to say it was currently occupied.

In 2014, another member of the family, Princess Michael, suggested in an interview with Tatler magazine that Apartment 1 would be perfect for Harry to move into when he got older and wanted to start a family.

Princess Michael said William and Kate have a "lovely big apartment, next to the Gloucesters, who I think will leave their enormous apartment because their children have gone".

She added: "They're rattling around this huge space and I think Prince Harry might go there. Then they'd be next door to each other - very good move."

Indeed Apartment 1 and Apartment 1A are as close together as it is possible to be - they are linked by adjoining doors so Harry and Meghan can come and go to see Kate and William and also visit young Prince George, Princess Charlotte and Prince Louis whenever they choose.

Prince George riding a rocking horse in his Kensington Palace home. Photo / Getty Images
Prince George riding a rocking horse in his Kensington Palace home. Photo / Getty Images

The first hint that Harry had chosen Apartment 1 came this year when a line of fir trees was planted to obscure the view of the apartment's entrance from the public walking up and down Kensington Palace Gardens, a road 100m west of Kensington Palace where some of London's richest people live - including Tamara Eccleston and Roman Abramovich.

Sources say that in recent days Meghan has taken her beloved dogs for a walk in the green, which is now obscured from public view behind the trees.

The Duchess of Cambridge is known to use the same piece of grass to walk her dog Lupo.

The couple will also be sharing quarters with Princess Eugenie who lives at Ivy Cottage, a three-bedroom property that was previously the family home of the deputy head of the palace's property section.