The hotel, which is based in the heart of Notting Hill, has been a mecca for the music and fashion crowd since it opened in the 1970s, with guests including the Rolling Stones, Patti Smith, U2, Johnny Depp and Kate Moss.
A Curious Group of Hotels bought the property at the end of 2013 and is in the process of restoring and modernising it throughout.
Co-owner Jessica Frankopan, who is leading the re-design, is planning a ‘an innovative reconfiguration of the rooms and an update of decor using bold colours’.
The group’s own-brand Green & Spring bath and body products will be used, alongside other trademark touches that are found across A Curious Group of Hotels’ properties.
However, the group stressed that the hotel’s ‘quirky charm and eclectic spirit’ would be maintained, and key pieces of furniture that hint at the property’s decadent past - such as the infamous round bed in room 16 and free-standing baths - would stay.
The hotel will remain open throughout the renovation.
The hotel is the fourth hotel addition for A Curious Group of Hotels, which also owns Cowley Manor in the Cotswolds, L’Hôtel and the Michelin starred Le Restaurant in Paris and the Canal House in Amsterdam
A Curious Group of Hotels co-owner Peter Frankopan said: “The Portobello Hotel is the perfect new addition to the Group - the history, size, location and spirit is completely in sync with Cowley Manor, L’Hôtel and Canal House and to have a London base is incredibly exciting.
“We love its bohemian charm and look forward to introducing it to a new generation whilst very much keeping its original spirit alive.
‘We have loved the Portobello for years, and are thrilled it has become part of the family.”
Double rooms at the hotel will start from £175 per night, based on double occupancy.
A recent report from business advisors BDO revealed that London’s boutique hotel segment is booming on the back of ‘burgeoning demand’ for such properties.
According to the report, London boutique hotels were the only ones that managed to increase their rates considerably in 2013, with average room rates up 5.1 per cent year-on-year, but occupancy stable at 78.5 per cent.
The boutique segment saw room yield growth of 4.6 per cent in 2013, compared to just 0.6 per cent room yield growth from top end hotels.
“Regular travellers, including new segments like the ‘millennials’ generation, continue to choose the boutique segment as an alternative to more traditional upscale accommodation,” said the report.
“Hotel groups are recognising the importance of this bracket and introducing new boutique hotel concepts such as W.”
Earlier this month, Firmdale Hotels announced that it would be opening the long-awaited 91-bedroom boutique Ham Yard Hotel in the heart of Soho in June.