Kate Middleton and Prince Wiliam
Prince William and Kate Middleton are due to move into Kensington Palace. Pictured: Duchess and Duke of Cambridge with Prince George and Princess Charlotte at St Mark's Church in Englefield, near Bucklebury in southern England on Dec. 5, 2016. Reuters/Andrew Matthews

Prince William and Kate Middleton have been enjoying their stay in Anmer Hall in Norfolk, but it looks like they have decided that a change of scenery was in order. The royals are due to move to London this fall, and their relocation will pave the way for a mega-extension to be built in Kensington Palace.

The renovation will provide over 1,500 square meters of extra space over three floors. This will transform the historic building's grade I-listed Orangery, Mirror reported.

Aside from the three-story building, the massive extension will also include a basement with two levels. According to Daily Mail, residential two-story basements are restricted in the local council, Kensington and Chelsea due to the disruption the construction will cause. However, the report noted that the officials might give the royals an exception.

READ: Kate Middleton copies Queen Elizabeth‘s grace and style

The underground expansion will reportedly allow staff to be moved and will free up the palace suites for the Duke and Duchess of Cambridge and their babies. Meanwhile, the 165-foot basement, which is currently used as a restaurant for the palace’s visitors, will be the new home of the staff. “The addition of a basement storey is required to allow for the accommodation of administration which must necessarily be moved out of rooms leased from the Royal Household in Kensington Palace,” the planning application said.

According to Glamour, the underground extension will allow both light and air to flow in. It will join 22 rooms and the kitchens that William and Middleton will use when they move into the Kensington Palace.

The Historic Royal Palaces, the charity which looks after the state apartments at the palace, have already forwarded the planning application. The decision of the council regarding the proposal is expected to be announced by the end of next month.

Prince William and Middleton will reside in London for majority of the year after the former completes his two-year pilot’s job with East Anglican Air Ambulance and before the start of his school term this fall.

How do you find the proposed massive extension in Kensington Palace? Is this too much for Prince William and Middleton’s move? Drop a comment below.