The Mayfair Hotel Megabuild | Preview (BBC Two)

Claridge’s Hotel - icon of old school glamour and favourite of celebrities and royalty - is undergoing its biggest transformation of modern times.

Filmed over six years, this documentary series follows the incredible engineering challenges involved in digging out a five storey mega-basement, adding four new floors to the top of the hotel and creating London’s most expensive penthouse.

In this first episode, Donegal miners work 24 hours a day to tunnel under the hotel by hand while upstairs, hotel manager Eugene tries hard to ensure loyal guests like David Walliams, Christian Louboutin and Damien Hirst remain undisturbed by the work going on above and below them.

Although it looks like business as usual at Claridge’s - one of London’s most luxurious five-star hotels, set in the heart of Mayfair - this couldn’t be further from the truth. Beneath the surface of this iconic, elegant, exclusive hotel, filled with glamorous guests, who enjoy the finer things in life, is a busy building site. An extraordinary engineering project is underway.

A group of specialist miners from Donegal have been brought in to create a five-storey basement, digging as far down as the hotel is high. On the top of the grade II listed building, two storeys are being carefully removed to add three new floors and 72 rooms and suites. The ultimate aim: to ensure this Mayfair classic is setting the standard for the next generation of uber luxury hotels.

As well as the addition of new luxury suites, a spa, swimming pools and restaurants, the crowning glory will be London’s most exclusive penthouse, spanning the entire rooftop of the hotel and featuring its own swimming pool, gym and lake, as well as an eighteen hundred square foot ‘Grand Salon’. The price for the most deep pocketed of guests is undisclosed but it will likely make it the most expensive hotel suite in London.

But there’s a catch. Claridge’s owners were insistent that the hotel remain open throughout the build. It has never closed its doors in its 200-year-history and the vision is for the guests to continue to enjoy the hotel, whilst remaining oblivious to the incredible industry taking place, just a few feet above and below them. As a result, the miners have had to tunnel by hand, working as quietly as possible taking everything out of a small two metre square hole at the back of the hotel.

This 3 x 60” documentary series, made over the last six years, follows the team, both on the build and the hotel side, as they contend with the challenges of balancing the needs of the building project with some of the world’s most well-heeled and high profile guests, including David Walliams, Christian Louboutin, Damien Hirst, supermodel Erin O’Connor, influencer Kate Elizabeth and celebrity Milliner, Stephen Jones.

The series also follows some of the key characters working in the hotel, including long-standing private butler Michael Lynch, who has worked at Claridge’s since he was 16 and hotel manager Eugene Leonard, who is caught between maintaining peace and quiet for the guests and the big build.

Pioneering engineer Jim Mackey was tempted out of retirement to oversee the basement build. He was the only person willing to take on running such an audacious project under a live, functioning hotel. He’s joined by daughter, Michelle as project engineer. And although they have their moments, they are a good team, embracing challenges like how to plunge a 50 metre tower crane through the heart of the hotel.

The Mayfair Hotel Megabuild, narrated by actress Emilia Fox, will follow this hugely ambitious operation, to discover whether the challenge and pleasure of maintaining the perfection of one of the world’s top five-star hotels, can really happen within a busy building site, without the hotel guests experiencing any disruption or noise.

Will they succeed and bring this passion project to life, whilst ensuring the busy, high-end hotel continues to thrive?

The Mayfair Hotel Megabuild begins Monday 2nd January on BBC Two.