You would never get away with it today. But in 1930s a super-rich couple built a luxury contemporary house on to a medieval palace and got away with it – although a few critics condemned the result as looking like a cigarette factory.

The irony is that English Heritage, who run the site today, would never get permission for such a project in these conservation-conscious times.

Judge for yourself whether it has worked on a visit to Eltham Palace, taking a peek into the lives of wealthy Stephen and Virginia (Ginie) Courtauld at their opulent country Art Deco mansion which incorporated the latest technology of the time – but also a peek at the place where King Henry VIII spent much of his boyhood.

Just drive straight up the M20/A20 to find these two past worlds merged into one, unexpectedly stumbled across in the middle of suburbia.

A visit is all the richer for the chance to explore the richly planted 19-acre grounds and gardens, set out in the Arts and Crafts style of contemporary gardens at Sissinghurst and Great Dixter in Sussex. Stephen and Ginie had big ambitions for their gardens at Eltham.

Today these are a fine example of 1930s garden design, incorporating the sunken rose garden and garden “rooms” divided by shrubbery. A spectacular herbaceous border pays tribute to the care lavished by head gardener Jane Cordingley and her team.

As the gardens include elements of the medieval palace, like diamond-pattern brickwork which was part of Elizabeth I’s royal lodgings built in the 1580s, another dimension is achieved. Against the backdrop of a medieval bridge and with panoramic views over London, the gardens owe their beauty to Jane's passion and inspiration. She has worked at Eltham Palace for seven years and is training two talented gardeners, one a former academic and the other, a former electronics engineer.While enjoying the grounds, look out for herons flying into the trees to their heronry and the green parakeets calling to each other.

The hammerbeam-roofed Great Hall is all that remains intact from the ancient past, which has links to Odo, Bishop of Bayeux in 1086, and then Anthony Bek, Bishop of Durham, a secular bishop, who presented the moated manor house to the future Edward II, although he continued to live there until he died in 1311.

From the 14th century Eltham was one of the largest and most frequented royal residences in the country. The Great Hall had been built for Edward IV in the 1470s as a dining hall for the court. Eltham continued to be frequented by the court until well into the 16th century and many international statesmen were entertained there.

Henry VIII, who spent much of his boyhood there, was the last monarch to spend a lot of time at Eltham, as Hampton Court and Greenwich were favoured. Elizabeth I visited Eltham only occasionally and Charles I was the last king to visit the palace, which fell into decay during the 17th century.

During the 18th century, the Great Hall was used as an agricultural barn and was the subject of an atmospheric watercolour by JMW Turner in about 1790.

The Great Hall came under threat in 1827 after demolition was advocated following damage to the roof by a gale. But a successful conservation campaign resulted in the hall being propped and repaired. Further work was carried out in 1894-5 and later in 1911-14.

By the 1930s the site was almost surrounded by houses and there were fears of suburbanisation of the palace’s remains. That is why Stephen Courtauld’s project was welcomed – as a means of halting the threat without Crown money being spent. So the site was handed over to the couple on a 99-year lease.

Stephen, whose shares in the family’s textile business generated a large fortune, employed Cambridge graduates John Seely and Paul Paget as the architects to design the new mansion, with a brief to include as much as possible of the medieval remains including the Great Hall, and to reflect the influences of Art Deco and contemporary ocean liners, as well as incorporating classical and historical motifs.

Leading designers and craftsmen were brought in to create lavish interiors and outstanding gardens, providing the setting for the couple’s art and furniture collections and ample space for entertaining.

All the mod cons of the time were built in, including a centralised vacuum cleaner in the basement. The motor was connected by pipes to sockets in the skirting of each room. A hose could be fixed to the sockets and the dirt sucked down to the basement.

Electricity was newly available so there were electric fires and synchronised clocks in most rooms and a loudspeaker system to broadcast records throughout the ground floor.

The kitchen contained two Jackson’s cookers and an electric Kelvinator refrigerator at a time when only 2.6 per cent of the population owned a fridge.

There was underfloor heating in the Entrance Hall, Great Hall and bathrooms and the rest of the property was served by central heating via coils embedded in the ceilings.

The entrance hall, with furniture designed by Swede Rolf Engstromer, is flooded with light from a concrete glass domed roof, 23ft in diameter. It is lined with Australian blackbean veneer and includes a marquetry panel depicting some of the Courtaulds’ favourite buildings, including palaces in Florence and Venice.

From 1995-1999 English Heritage took on the job of getting the house and hall ready to open to the public, it installed replica furniture in the entrance hall together with a reproduction of the original circular Marion Dorn carpet which is now in the Victoria and Albert Museum.

In the drawing room designed by Italian Peter Malacrida, two Veroneses, Astronomer and Patriarch, have been newly reinstated, courtesy of the National Gallery of Zimbabwe.

Art Deco inspired the ribbed, coved and mirrored ceiling in Ginie Courtauld’s boudoir, which was also designed by Malacrida. Here, the sofa is an early example of built-in furniture. But the piece de resistance is a leather map over the fireplace, depicting Eltham Palace and its surroundings. It echoes a map on board Cunard Line’s Queen Mary. Indeed, many other elements of the Art Deco interiors are similar to those on board Queen Mary.

Stephen Courtauld’s suite, designed by Seely, has costly Sanderson block-printed wallpaper depicting Kew Gardens on the side walls. There is a walk-in wardrobe and blue and green-tiled bathroom which adds a Mediterranean air.

Ginie’s bedroom, designed by Malacrida, is a contrast to Stephen’s, and mirrors her flamboyant personality. It has curved walls lined with maple flexwood, recreating the image of a temple. Her bathroom is the most opulent room in the house with gold leaf decorating a curved backdrop to the bath, which has gold-plated taps. There is a vaulted ceiling and walls lined with onyx.

The dining room is an example of Moderne style, favouring geometrical shapes. The recessed central ceiling is covered in aluminium leaf with built-in concealed lighting to make the metal shimmer at night.

For all their work and vision, the Courtaulds only stayed at Eltham Palace for a relatively short time, moving to Muclairn, in Scotland in 1944.

In 1945 the Army Educational Corps took over the 1930s building and the Ministry of Works took over maintenance of the Great Hall. In 1984 English Heritage took on the Great hall before taking responsibility for the whole site in 1995 and undertaking a £1million restoration.

The stunning rooms of the mansion have been used as a set for many films and television programmes, including Bright Young Things, I Capture the Castle, The Gathering Storm and Antiques Road show. Look out for Brideshead Revisited and Belle du Jour with Billie Piper, both recently filmed at the palace.

Visitors are welcome to picnic in the grounds or enjoy refreshments in the tea room. Eltham Palace is open to the public from Sunday to Wednesday.

Tickets cost adults £7.90, children £4, concessions £5.90; family ticket £19.80. Gardens only £4.90/£3.70/£2.50.

It costs £7,000 to hire Eltham Palace as a striking backdrop to your wedding; details from the Hospitality Manager on 020 8294 2577. It is also used for training seminars, small and large gatherings.

The address: Eltham Palace, Court Yard, London, SE9 54E; email www.english-heritage.org.uk/eltham