North west London postcodes NW3 and NW8 are among the top 10 most expensive in the UK according to the Zoopla Rich List 2015.

Ham & High: Woodlands, Courtenay Avenue, N6, £20,000,000Woodlands, Courtenay Avenue, N6, £20,000,000 (Image: Archant)

Despite estate agents in both areas reporting a slowdown in the prime north London market in recent months, average asking prices in NW3, covering Hampstead, were £1,452,099, the eighth most expensive in the country. Those in NW8, the postcode for St John’s Wood were £1,395,999.

At the same time, the Zoopla figures show that the number of “property millionaires” – people whose home is worth £1million or more – increased 8.3 per cent on last year to top half a million for the first time.

There are now 10,958 streets in Britain with average asking prices of more than £1million.

Nearly half (43 per cent) of those are in London, with two streets in Highgate and one in Hampstead ranking as some of Britain’s priciest.

Ham & High: Treetops is on Compton Avenue, N6, for sale through Glentree International for £24,000,000Treetops is on Compton Avenue, N6, for sale through Glentree International for £24,000,000 (Image: Archant)

Courtenay Avenue, N6, a private gated road near Kenwood and The Bishops Avenue, had north London’s highest property value and is Britain’s fourth most expensive street, with average asking prices of £19,609,231.

Nearby Compton Avenue ranked sixth with an average asking price of £12,049,363, while Frognal Way in NW3 came tenth in the list with house prices of £10,702,421.

Trevor Abrahmsohn of Glentree International, who currently have properties for sale on these roads said: “Over time Courtenay Avenue and Compton Avenue have gained increased popularity since they are both cul-de-sacs with a 24-hour security at one end (which restricts access) and Highgate Golf course at the other.

“These tree lined avenues represent the best combination of a country house and a town house and the prices that you would pay for this cherished hybrid entity is one third of what you would pay in Kensington.

“Two golf courses are within walking distance and a commercial, private airport is within half an hour’s travel.

“Today Courtenay and Compton Avenues appeal to wealthy local and international buyers and are probably some of the most sought after locations in London. Prices range from £10million to over £50 million.”