Kate Middleton and Prince William confirmed the happy news that they're expecting their first child on Dec. 3, but the couple of 18 months have long been in nesting mode.

Currently living in a quaint Welsh cottage, the royals, both 30, will relocate next summer to make London's Kensington Palace their home. Taking over Apartment 1A in the four-story, 20-room flat in the midst of a $1.5 million renovation, the pregnant Duchess intends to make her new digs feel especially homey for their baby-to-be.

PHOTOS: Prince William and and Kate Middleton's first year of marriage

"Kate is keen to put her stamp on the place with things she's bought on her travels," says an insider of Middleton, who recently toured Southeast Asia with her husband as part of the Queen's Diamond Jubilee. "She felt certain pieces would be nice 'when we have a bigger home.'"

Relocating to Kensington Palace in order to beef up their growing family's security, Middleton and her husband feel the London digs will allow their child to grow up "in a secure environment," adds an insider.

VIDEO: William and Kate talk baby plans

Confirming news that the couple will soon give birth to the future king or queen of England Monday, Dec. 3, St. James's Palace also revealed that pregnant Middleton has been hospitalized in Central London with Hyperemesis Gravidarum, an acute form of morning sickness. "As the pregnancy is in its very early stages, Her Royal Highness is expected to stay in hospital for several days and will require a period of rest thereafter," the Palace statement read.

This article originally appeared on Usmagazine.com: PICTURE: See Pregnant Kate Middleton, Prince William's New London Home