Two penthouses on Park Lane in Mayfair which have been renovated by interior designer Nicky Haslam and developer are  thought to be the most expensive rental properties currently in the UK.
 
Gary Hersham from Beauchamp Estates (020 7499 7722), who is letting the penthouses out along with Wetherell (020 7529 5566), says that the owner of the penthouses, a wealthy property magnate, has spent nearly a decade getting planning permission and doing up the apartments at a cost of about £8 million.
 
The apartments at Avenfield House with open views of Hyde Park boast terraces made with unpolished marble and water features, air-conditioning, Lutron lighting and Creston controls for all the other gadgetry. Mr Haslam has incorporated floating double staircases with leather handrails (he says he got the idea after reading an Evelyn Waugh book), a gentleman’s dressing area with Stingray on the wall and etched antique mirrors in the lady’s equivalent area.
 
Mr Haslam, who has designed interiors for Bryan Ferry, Rupert Everett, Ringo Starr and Rod Stewart among others, says his client wanted a totally different look in the opulent apartments and ‘no naff so-called minimalism, steel, frosted glass and miles of beige. He wanted proper architecture and design instead of styling’.
 

avenfield house mayfair
Rent: £25,000 a week

When Mr Haslam designs a high-end property, he say he does not have a specific person in mind, ‘more a sort of chimera of who might buy. I was aiming for a welcoming smile from someone when they first enter the rooms. I hope they feel they can plonk their suitcase down and just live here happily’.
 
One person might rent both apartments, and although they are different, ‘there is a continuous theme that is subtle, but not distracting, that would tie them together,’ points out Mr Haslam.
 
‘They are glamorous and private,’ he explains, emphasising how the location of the sky-top homes lends a feeling of free-flying like a bird above the world, with the soliditary of the architecture anchoring you to the real world. The back view of the rooftops of central London is especially Mary Poppins-like, while I would say the Hyde Park view, which gets all the attention, is a bit dull.’
 
Who will be likely to hand over the not insubstantial asking price, however? ‘As it costs about £7,000 a night for a suite at Claridges, sophisticated Arabs, top-of-the-range princes or film stars can save money renting out a penthouse that is homely but flamboyant,’ suggests Mr Hersham, who believes the penthouses could well suit a big family – and a pretty prosperous one at that.