And the royal property that's ringing in the changes more than any other is undoubtedly the historic Kensington Palace in London, now home to 15 members of the royal family, spanning three generations.
The palace, a royal residence since the 1600s, has taken on three new arrivals in the last month, making it easily the most bustling of the royal family's many grand homes.
Within its grounds are a host of separate properties, ranging from (relatively) humble cottages, to a grand, 20-room apartment occupied by Prince William, Kate Middleton and their young family.
As well as royal living quarters, which tend to be relatively sedately decorated, it is also home to lavish state rooms used for grand occasions, like this one:
William, Kate, and their children are not only the largest group of royals in Kensington Palace, but the closest to the throne.
Perhaps unsurprisingly, they have the best rooms going. The family of five occupies Apartment 1A, a collection of 20 stately rooms with a commanding view of Hyde Park.
They moved to Kensington Palace full-time in October 2013, not long after their first child, Prince George, was born. Princess Charlotte followed in 2015, and Prince Louis in April 2018.
The public rarely get to see inside, but photographers were allowed to take photos of a reception room when William and Kate hosted the Obamas in 2016:
We also saw another view (or maybe even another room) where Prince George played on a rocking horse before meeting the President.
Significantly less grand is the two-bed cottage inhabited by Prince Harry and Meghan Markle, which will also be their marital home after they marry on May 19.
The cottage, nicknamed "Nott Cott" and often described as "snug," has been Harry's home since 2013.
Meghan moved in just after their engagement was made public in November 2017. Harry proposed to Meghan when they were spending an evening together at Nottingham Cottage, surprising her while they were roasting a chicken.
After announcing their engagement, they gave an interview from the cottage, sitting on its sofa, which is one of the only times the public has seen inside:
The newest royals at Kensington Palace are Princess Eugenie, who is William and Harry's cousin, and her fiancé Jack Brooksbank, a London socialite.
According to The Sun, the couple moved in to a cottage right next to Harry and Meghan's around the same time Kate was in hospital delivering Prince Louis.
The couple announced their engagement in January, a few weeks after getting engaged while vacationing in Nicaragua.
They are getting married at Windsor Castle in the same church as Harry and Meghan this October, but the occasion is likely to attract much less publicity.
The Duke of Gloucester, one of Queen Elizabeth II's cousins, lives in Apartment 1 with the Duchess of Gloucester, his wife.
Like William and Kate's home at 1A, the dwelling is a large complex of rooms in the main palace building. The two used to be one enormous set of rooms until they were divided in the 1950s.
The complex has 21 rooms, slightly pipping the size of William and Kate's, but few details are available other than its overall size.
Prince Michael of Kent, another of the Queen's cousins but from a more junior line, lives in the main palace building with his wife.
She is known as Princess Michael in the old-fashioned tradition by which the wives of princes take their husband's name.
This same rule means that Kate can technically be referred to as Princess William of Cambridge, but the name is not widely used.
Their apartment, number 10, consists of five bedrooms and five receptions rooms. They used to have use of the property rent-free, but since 2008 they have been paying a reported £10,000 (R170,000) per month in rent.
The Duke of Kent, Prince Michael's older brother, also lives in the Kensington Palace grounds with his wife, the Duchess.
Their home, Wren House, is named after the famous British architect Christopher Wren, who built St Paul's Cathedral and a slew of properties for the royal household.
Few details about their home have ever been made public. It is physically between Ivy and Nottingham cottages, and appears to be of a similar size.
Elizabeth II lives at Buckingham Palace with her husband, Prince Philip. It's around 3km from Kensington Palace, across Hyde Park and Green Park.
It's not quite as cosy as living on the same property — but if Her Majesty ever wants to drop in on her cousins, grandchildren or great-grandchildren, they aren't far away.