Entry intercoms, electric gates, immaculate lawns and clipped hedges – all of these usually point to a highly desired and wealthy street. But research released today has revealed which ones can claim to top the list of the UK’s most expensive.

The costliest is Wycombe Square (pictured), a ‘new’ square of 19  luxury Georgian townhouses and 48 apartments all snapped up by a raft of bankers and pop musicians back in 2005.

The square, which is set around a central garden, has regularly been in the newspapers as various high profile residents have bought in and out of the postcode, particularly when senior Barclays investment chief Bob Diamond purchased his house there for £10.5 million in 2005, only to sell it for £25 million in 2008. At the time Diamond had been hired by London mayor Boris Johnson to raise money for the capital’s deprived teenagers.

The average price for a home on the square, the research by Halifax reveals,  is a more modest £5.4 million, but that puts it at the top of the UK’s rich-list property pile, closely followed by exclusively London and South East roads. These include:

1. Wycombe Square, Kensington,London W8 – £5.4m

2. Ingram Avenue, Hampstead, London NW11 – £4.8m

3. Cottesmore Gardens, Kensington, London W8 – £4.2m

4. Mallord Street, Kensington, London SW3 – £3.9m

5. Stormont Road, Highgate, London, N64 – £3.37m

6. Brunswick Gardens, London, W8 – £3.08m

7. Bedford Gardens, Kensington, London, W8 – £2.9m

8. Sloane Gardens, Kensington, London, SW1 – £2.7m

9. Parkside, Wimbledon, London, SW19 – £2.68m

10 Paultons Square, Kensington, London, SW3 – £2.66m

Outside of the top ten only roads in Leatherhead, Virginia Water and Sevenoaks were in the next ten most expensive, and the dearest roads in the north and north west of England are still five times cheaper than their counterparts down south – particularly when compared to the London Borough of Kensington Chelsea.

“This borough has long had a global appeal, but the fall in the value of the pound has helped to attract foreign buyers over the past year despite the worldwide recession,” says Nitesh Patel of the Halifax.

We’re increasingly being told about the environmental impact buildings can have on the climate, not least from people like Prince Charles. So it may come as a surprise that the least eco-friendly building in London has been revealed as being good old Buckingham Palace.

The Queen’s des res scored 0 out of 10 in a survey of 170 buildings in London by renewable energy firm Navitron. They were exploring the energy efficiency of buildings in the capital city and many were found to be woefully inadequate. By using thermal imaging techniques, they were able to see how well insulated the buildings were – or were not – and whether heat was contained within the buildings or madly escaping.

The thermal imaging survey of Buckingham Palace revealed it to be a hotbed of activity. Rather than heat being contained within the Palace, it was shown to be pouring out through the building in every area possible – through the roof, the walls, through curtained windows and even through cracks.

As it was built in 1820 and contains over 600 rooms, it’s not surprising that the Palace is experiencing problems with energy efficiency. The Queen has, however, apparently set up an energy-saving committee to try and tackle the problems and reduce consumption.

But it wasn’t only the Queen’s residence that was problematic. It was only last month that the Government launched a new scheme aimed at helping households reduce their emissions by 50% by the year 2050, yet some of the key Government buildings in London, such as the Ministry of Defence, MI6 HQ, the Treasury and the Home Office, were all found to be major polluters.

The full list of top 12 non-green and leakiest buildings in London is as follows:

1. Buckingham Palace
2. DECC (Defra)
3. The Ministry of Defence
4. Horse Guards Barracks
5. The Shell Building
6. The Home Office
7. Houses of Parliament
8. The Treasury
9. Portcullis House
10. MI6 HQ
11. The Albert Hall
12. St James’ Palace

If you’d like to try and reduce energy emissions in your home and make it more eco-friendly, then some simple ways of making a difference include swapping single glazing (as in the palace) for double glazing, improving draught-proofing in your home, using energy-saving light bulbs and turning off lights when you’re not in a room. For more ideas, take a look at our guide to energy saving.

West Lodge, in Hyde Park

It’s not often that you get the chance to find a rental property in the heart of a city, yet surrounded by nature and wildlife. But that’s the case in the city of London, where a few unusual properties have recently come up for rent – located in some of the best loved Royal Parks.

As part of the Royal Parks’ Better Buildings Programme, seven lodges in various Royal Parks in London have been decorated and updated and are now being let to tenants. The idea is that letting the buildings out will be a better way of generating revenue and a far more effective use of the buildings. Plus, they make very unique homes to lucky renters.

The buildings all have a long history, which is fascinating in itself, and offer tenants the chance to live in the midst of some of the best green spaces in London, which are packed with nature and wildlife. But most are also located very close to the life of the city and benefit from sought-after parking spaces. Tenants also get the added advantage of having a gardening service thrown in too, as the Royal Park gardeners mow the lawns on a regular basis.

Blackheath Gate Lodge, in Greenwich Park

Two of the Royal Park homes that are currently still available are West Lodge, in Hyde Park, a striking neo-classical style pavilion lodge with one bedroom, located minutes from Knightsbridge and the Royal Albert Hall, and Blackheath Gate Lodge in Greenwich Park, a three-bedroom early Victorian house, which backs onto the deer enclosure. For city fans who are lovers of history and nature, you can’t get much better than this.