They are the crème de la crème, the icing on the property cake, the streets that are paved with gold.
Right in the centre of London, on beautiful Georgian Squares and streets with Monopoly board names, are the super-prime properties that everyone wants but very few can own.

Whatever turbulence there might be in international banking and the world’s economies, these homes will always command prices way above the rest.

So what makes the super-prime streets so super? It’s a complex combination of exclusive and historically famous location – think Park Lane or Berkeley Square in Mayfair – fine architecture such as the stucco mansions of Holland Park, and proximity to the best restaurants and shops, whether they’re on Bond Street or the boutique streets of Chelsea.

The best addresses will also be those where properties are all of a similarly high quality: a fine Georgian home, however impressive, will never make the top grade if too close to a run-down office block.

The difference between a super-prime street and ‘just another’ street can be a matter of metres. Indeed, one of the fascinating things about London property is that two almost identical houses can vary dramatically in value depending on their precise postcode. Cross a street and the price of a home can soar; turn a corner and values plummet.

Also part of the excitement of our capital is that, while many central areas and landmark buildings remain protected, the dynamics and demographics of a neighbourhood can subtly shift, to bring in new life with changing tastes and fashion. A refurbishment here or a designer name there can start the golden ball rolling, with demand for homes then rising to push a street from prime to super-prime.

Not that long ago you could have strolled down some of Mayfair’s finest streets after 7pm without passing a single soul. Those who owned property here seemed to go elsewhere to enjoy their leisure hours in the capital. Always smart but once dominated by antique shops and art galleries, Mount Street, which runs from Park Lane to Berkeley Square, has within the last two years become super-cool. The refurbishment of Scotts, one of London’s top restaurants, started the upward trend, with the fashion cognoscenti following. There are now two Marc Jacobs stores to tempt the stylish, as well as Lanvin, Carolina Herrera, Christian Louboutin and Balenciaga among other designer names. The most sought-after restaurants and shops are now here and in the surrounding streets, breathing life into the beautiful old buildings and replacing a grand but  starchy image with glamour and style.

This ‘Advance to Mayfair’ brings property owners an even more solid-gold investment than before, as demand grows from a wider range of age groups and lifestyle. Whatever turbulence there might be in international banking and the world’s economies, these homes will always command prices way above the rest.

The condition of a property in super-prime areas is also more significant than in other areas of the capital. In prime pied-à-terre territory and where international buyers don’t want a property that needs work, a premium is paid for homes in perfect condition throughout.

So those who want some of London’s glamour and style have the option of renting for short or long periods, or of buying a home that needs refurbishing, or in an area close to the centre but just outside the super-prime postcodes. But for the world’s super-wealthy, nothing beats the cachet of London’s most famous addresses: there is only one Park Lane and only one Berkeley Square.

Boardrooms becoming bedrooms

One positive aspect of recent economic turmoil is that beautiful old buildings used as commercial premises are being restored to the impressive period houses and apartments they once were. There are fewer financial firms maintaining ultra-smart offices in Mayfair, and throughout London’s prime postcodes boardrooms are becoming bedrooms, with opportunities to own homes for the first time in decades at some of the most exclusive addresses.

“The value in many of these buildings is now residential, which is appreciating rapidly, rather than commercial,” says Tim Macpherson, head of London Residential at Carter Jonas. “We’re seeing a number of mixed-use buildings gaining a higher percentage of apartments, The estate has succeeded in attracting the right mix of independent shops which adds to the atmosphere and appeal of an area.”

What else is happening in London’s super-prime postcodes?

Right next to Hyde Park and sandwiched between Notting Hill and the West End, Bayswater is in the heart of London but property prices have remained comparatively low because of the dominance of budget tourist hotels and B&Bs along the Bayswater Road. All that is changing, with the smartening up of W2 highlighted by the transformation of a magnificent white stucco terrace on Lancaster Gate overlooking the park, into 77 super-luxurious high-ceilinged apartments.

“The Lancasters will have a huge effect on W2, currently the most undervalued area of prime central London,” says Tim Macpherson, who heads up Carter Jonas’s London residential division. Just the other side of the park in Knightsbridge, you could pay £4,000 per sq ft, if you wanted to, for a deluxe glass-walled apartment without a view of the park. For half that, a high-spec spacious apartment in Bayswater with park views and all grand architectural details restored might seem a better idea to some. The canny buyer should not wait too long, perhaps. Record prices are being achieved for the best Bayswater homes, says Macpherson.

“We recently sold a property at £2,650 per sq ft, which is far beyond anything achieved previously.” Between Oxford Street and Regent’s Park, Marylebone is another central hotspot, hardly noticed 10 years ago but now the talk of the town and stuffed with celebrities and media types. Its higher profile – and higher prices – are largely the result of smartening up properties by the major landowner in the area, the de Walden estate.

The estate has succeeded in attracting the right mix of independent shops which adds to the atmosphere and appeal of an area.” and stylish eateries to enhance the appeal of ‘Marylebone Village’ and push it into the super-prime league. Marylebone High Street now buzzes with life but is not choc-a-block with tourists in summer, leaving plenty of room for people watching and celebrity-spotting while lunching al fresco. Portland Place and Mansfield Street are the most expensive streets in this area of London, with elegant Montagu and Bryanston Squares coming a close second along with famous-name streets such as Wimpole and Devonshire. With Baker Street running through the middle, the area is steeped in literary, musical and medical history with no shortage of blue plaques.

So how much can you expect to pay for London’s best addresses?

Price will vary across type of property – per square footage, houses are often not as expensive as flats, and flat prices will vary depending on lease length. In Mayfair prices are normally between £1,750 and £2,000 plus per sq foot; in the Hyde Park and Bayswater area prices can vary between £1,000 and £2,500 and above. But for a one-off property in the most exclusive of locations, the price is simply dictated by what someone who wants it is prepared to pay. A mansion in Kensington Palace Gardens, for example, has been sold for £250 million.

“The Holy Grail of London property is a lateral flat across the principle floors of the first or second floors of a building,” says Sinead Canning at Carter Jonas’s Knightsbridge and Chelsea office, “with views over communal gardens, a long lease, a porter and parking.”

Short-leases are one way of buying into central London at a lower price, and then extending the lease at a later date. As many as 30% of the properties on Eaton Square, for example, have less than 21 years on the lease.