Many Londoners aren't aware of it but the city is in the midst of a massive transformation that will turn a once-undesirable area south of the Thames into a thriving residential and commercial district within five years.

The refurbishment of the famous Battersea Power Station is the centrepiece of the vast STG15 billion ($A28 billion) Nine Elms project on former industrial land that historically served the affluent north of the city.

Stretching from Lambeth Bridge to Chelsea Bridge, the area is home to the New Covent Garden Market, which supplies the English capital with much of its fresh fruit, vegetables and flowers.

But it’s relocating nearby and the Royal Mail is moving out of the area altogether.

In their place will be 18,000 new homes and more than 600,000 square metres of commercial space over almost 200 hectares.

Apart from the power station, the site will also feature a new United States embassy, opening in 2017.

The US government’s decision to relocate from Mayfair was key for Nine Elms. It gave other investors confidence the project would succeed.

The Northern Line is being extended at a cost of STG1.0 billion ($A1.9 billion) with two new tubes stations at Nine Elms and Battersea.

They’ll open in 2020 with local councils then hoping to build a new STG40 million ($A76 million) pedestrian bridge over the Thames by 2030.

But the centrepiece of the project will undoubtedly be the redeveloped Battersea Power Station.

The top river-front penthouse is still available to buy – if you have a spare STG30 million ($A57 million) or so to splurge.

The art deco building, with its iconic four white chimneys, became famous when depicted on the cover of Pink Floyd’s 1977 album Animals.

Left derelict over the past three decades, it’s scheduled to reopen in 2019 with 254 apartments, three levels of retail stores, six floors of office space, a cinema, a hotel and a host of restaurants.

But only the super-rich will be able to live atop the former coal-fired power station, which was decommissioned in 1983.

There are only 20 apartments left with an entry price of STG3.45 million ($A6.5 million).

A four-bedroom apartment overlooking the river with a private terrace on the shoulder of one of the front towers is worth STG13 million ($A25 million).

But the top north penthouse, spanning the front width of the power station, is “the jewel in the crown – the king of the castle”, according to the sales team.

It has 6500 square feet of internal space and 3000 square feet of external space including a terrace that runs onto the two shoulders below the river-side chimneys.

“It’s the only one of its kind, in the only building of its kind, with full river-facing views so it’s going to have a price tag to match,” a spokeswoman said.

She wouldn’t say what it could fetch but baulked at a suggestion it could reach STG60 million ($A114 million). Many believe it will sell for about STG30 million ($A57 million).

A consortium of Malaysian investors is behind the STG8 billion ($A15 billion) power station project, which comprises three phrases.

Phase One includes two new buildings on the western side of the power station with 866 apartments.

Construction began in mid-2013 and residents are scheduled to move in by the end of 2016.

There are only five penthouses left starting at STG7 million ($A13.3 million). The most expensive is STG20 million ($A37.9 million).

Phase Three, to the south of the power station itself (Phase Two), will include 1300 homes in five modern buildings by Canadian architect Frank Gehry and another designed by Englishman Norman Foster. It will open in 2020.

Critics are furious that Phases One and Three, and other residential towers to the east being constructed as part of the overall Nine Elms development, will obscure the power station from everywhere but the north.

But the Malaysians insist if they hadn’t stepped up the power station wouldn’t have been saved at all. Previous attempts to redevelop the site failed due to its size and cost.

“At the end of the day only development would secure this site,” spokesman David Twohig says.

“You were always going to have buildings around it, it’s either that or leave it as a greenfield and we saw what happened for the past 30 years when it was a greenfield, the building starts to fall apart.”

Twohig says the project will actually open the site up to the public for the first time.

“At the northern frontage, where people are coming along the river bank, we’ve provided this large six-acre public park right in the front that protects that facade (so in can be viewed from the river),” he said.

“So no matter whether you’re east, west, north or south you’ll always have that silhouette – we didn’t want to obscure that.”

While Pink Floyd’s album cover made the power station popular it’s central London location saved it.

If it was halfway to Wales it likely would have been knocked down years ago, Twohig argues.

By Julian Drape