Queen Elizabeth has wheelchair lift installed at Balmoral estate

Queen Elizabeth II has had a "wheelchair-friendly" lift installed at Balmoral.

The 95-year-old monarch has kitted out her favourite cottage at her Scottish estate - Craigowan Lodge - with a more accessible lift after she is believed to be suffering from mobility issues.

The lift - which has the capacity for three adults or one wheelchair user - is believed to have cost £20,000 (NZ$38,000) to fit and was put there to make it easier for Her Majesty to retire to bed.

An anonymous royal source told the Sun newspaper: "For many years we have thought it would be the perfect place for the Queen to spend more time when she's older. It's one of her favourite places in the country.

"With the proper lift, and now this new security, it can effectively be sealed off so she can spend much more time there quietly in her late 90s."

Ingrid Sewell, the editor of Majesty magazine, shared the Queen "loves" being at the cottage.

She said: "Craigowan is one of the Queen's favourite homes. She loves being there.

"The idea of making it easier for her so she can spend more time there in the future is a great idea.

As Queen Elizabeth gets older, we won't be seeing her out and about as much. Photo / Getty Images

"It's a big, big house. The security makes it very safe.

"It makes perfect sense. It's a home she has always enjoyed and it gives her a bit of independence."

Penny Junor, a royal biographer, believes the public "will see her out and about" less and less.

She said: "I don't think we will see her out and about as much as it's quite clear her mobility is challenged."

She added: "She does love Scotland, but I would not think she would use it [the cottage] year round. It's a lovely place for the summer but it's pretty cold and bleak during the winter. But it is a very favourite place for her."