The season for enjoying outside space is upon us. A penthouse apartment with a wide balcony overlooking the Thames is the ultimate prize - somewhere with show-off views, perhaps, of Tower Bridge, St Paul's Cathedral and the Gherkin, with Canary Wharf one way and Hyde Park in the distance another.
Luxury rooftop retreats in posh postcodes come at a price - eight figures in some cases. As a rule of thumb, the closer to Harrods, the more expensive the property will be because Knightsbridge is where the global rich want to live.
But the rise of buildings along the Thames over the past decade has had a democratising effect.
Outside this exclusive inner ring there are now rows of balconied homes offering buyers on a variety of budgets a chance to share the views and enjoy their own outside space, in the air and on the ground.
'Balconies have become a must-have accessory that can easily add £50,000 to the price of an apartment'
More than 60 per cent of new apartments now have some type of outside space, three times the level of 10 years ago, says Andrew Palmer, development director of property consultants DTZ.
"Previously, if you wanted decent outside space you had to buy a house with a garden. Today you can live in a central London flat and have that liberating feeling of being able to step outside and into an intimate area of your own."
New building techniques, new attitudes and a more demanding buyer are all moving the modern home forward. People should not be punished for living in cities, and buyers have proved that they are prepared to pay a bit extra for a balcony or courtyard.
Outside space chimes with the fashion, and need, for fresh air, to be green and a healthier life. Homes with outside space have become a key component of the new wave of architecture that is transforming London.
The latest riverfront and parkside developments feature giant stepped terraces, curvy wraparound balconies or conservatory-style winter gardens that form an extension to the main living space - great during summer months and designed to be enjoyed year-round.
Boutique homes are appearing on landscaped inner-city plots and a fresh generation of iconic residential skyscrapers - Strata at Elephant & Castle, Shard of Glass at London Bridge, Heron Tower in the Square Mile - are enticing buyers with their awesome vistas across central London.
Balconies, even small balconies, have become a must-have property accessory that can easily add £50,000 to the price of an apartment. Big terraces, creatively landscaped, can boost a property's value by much more.
"In a crowded city, private outdoor space is the luxury that will always add value," says James Hyman of estate agent Cluttons. "The exact premium can be anything between 15 and 35 per cent, depending on size, aspect, view and design quality."
Height of fashion
A recent YouGov survey revealed that 53 per cent of homebuyers ranked outside space as the single most important attribute of a new home when asked to choose from a list of 20 features (private parking and energy efficiency came second and third).
At some new developments in London, communal - but still private - outside space is also a big draw because it is an integral part of the address, like a traditional garden square where access is restricted to resident key-holders. Often apartments are built around water gardens, landscaped courtyards and continental-style piazzas where residents can relax or socialise.
Arundel Square is one of Islington's fastest-selling developments, due largely to the clever integration of inside and outside space. Some apartments have patio gardens, while others have glass-fronted balconies or roof terraces overlooking an upgraded Victorian garden square, extended by a third and improved by fresh landscaping, all part of the Barnsbury conservation area facelift.
Apartments (115 in total) are reached via a new road, gated at each end, which runs across the new side of the square. Buyers can choose from 32 different apartment layouts, ranging from studios to duplexes to penthouses. Wide floorto-ceiling glass panels maximise views of the square, while interior design is well above average. Prices start at £285,000; penthouses from £1 million. Call 020 7609 5123.
At Imperial Wharf in Fulham, a new 10-acre riverside park includes picnicking lawn and sensory gardens with three landscaped themes - Aroma, Sight and Touch - providing year-round interest.
Hampstead is the perfect place in London for those who want town and country living combined. The views from this high point in the capital are magnificent, while the Heath's 800 acres are a giant back garden for residents lucky enough to live close by.
Kenwood Place is a select scheme of 21 grand apartments perched on an elevated plot bordering the Heath - a rare position. Unusually, too, the architecture is modern: three cube-shaped blocks clad in a dusky pink-coloured natural stone and with floor-to-ceiling bronze-framed windows, nestling below the tree line and invisible to the Heath's joggers and dog-walkers.
Clean-cut apartments range from 990sq ft to 3,294sq ft and are lightfilled lateral spaces with sleek interior design. Discreet balconies and terraces have electronically operated external shutters and some homes are dual or triple aspect. Prices range from £3.75 million, including underground parking space. Call 020 3213 0019.
Cheaper homes with inspiring outside space include Queensbridge Quarter, a new development close to London Fields in Hackney that has won design accolades. A south-facing penthouse with double terrace costs £550,000. Call Fyfe McDade on 020 7613 4044.
Eyot Heights is part of the Bermondsey Spa regeneration zone in Southwark, an up-and-coming patch and still good value. Smart duplex apartments are for sale, including one with a 70ft by 25ft roof terrace, priced at £525,000. Call Savills on 020 7231 1200.
The Printworks at Elephant & Castle has new penthouse-style flats with fullheight glass and decked terraces offering views of the West End and City skyline. Prices from £350,000. Call 020 7613 1888.
This Place, a conversion of a former college in Wandsworth Road, has topfloor flats with huge 800sq ft terraces that are bigger than most two-bedroom flats. Prices at the development range from £220,000 to £500,000. For information, call 020 7409 8756.
The "Presidential Residence" at Bridges Wharf, on the Wandsworth waterfront, is trumpeted by developer Weston Homes as the best-value penthouse in London - a lofty claim not without justification.
At £2.5 million, you would expect something special. The price is mostly about the glamour of its fabulous curved reception and kitchen space plus the "open-air outdoor entertaining area" - or terrace - wrapping around the apartment, which, because of its prominent position on the curve of the river, provides one of the finest panoramic views of London, virtually 360 degrees. An internal glass winter garden acts as a noise buffer to the adjacent London Heliport, a handy facility for globetrotting businessmen. Call 0845 638 5005.
'It's magical at night'
Fred Governo and Helen Cobb enjoy stunning east-west views along the Thames from their penthouse flat at Imperial Wharf in Fulham. The couple, in their early forties, bought their three-bedroom home in 2000, spotting the great location of a luxury waterfrontage in what was then an emerging quarter. The 1,600-home development is now complete.
All the main rooms have direct river views, plus there is a wraparound terrace with a sweeping vista. "There's a 10-acre park, gardens, riverside walkways and restaurants with outside eating areas, and the Imperial Wharf train station opened last year. We've had some great cocktail parties, and at night it's quite magical," says Mr Governo.
The couple have a business in the Middle East and are moving to a Jacobean manor house in Bath. The penthouse is for sale at £1.99 million through Foxtons (020 7565 4000).