Before the advent of planning laws, anyone with a country house, the desire for extra space and some cash to spare would simply stick on an extra wing. Hence the proliferation of fine old piles across the country with a Georgian facade, a Victorian extension on the side and remnants of cellars that date from Tudor times.

These days, however, only the bravest owner of a country pile would take on the army of planners and conservation officers who control what we do with our homes, especially if the pile in question is listed.

John Hedgecoe, 72, a photographer and writer who has been shooting the great and good for 50 years, has done just that. Eight years ago, Hedgecoe — who, aged 29, took the picture of the Queen that was turned into the design still used on postage stamps — decided that Oxnead Hall, his 16th-century home in Norfolk, didn’t look quite complete. So he decided to expand the nine-bedroom house by adding a three-storey extension to its front — creating an impressive facade in the style of the original main building, which was demolished several centuries ago, to give a total of 15,676 sq ft of living space.

“[What was there] wasn’t a very good ending to the house, so I thought it needed to look better,” Hedgecoe says. “We were trying to get it back to how it once was — give it a bit of its grandeur back,” chips in his wife, Jenny. It took several years to get permission — the property is Grade II*-listed, after all — but the conservation officer finally agreed. So there the extension stands: the same red brick as the rest of the house, with the same stone windows, gothic-style portico and pitched tile roof. The only snag is, it’s not finished. While the exterior blends in well with the rest of the house — even if the bricks are not yet weathered — the inside is a mass of rubble. Neither the floors nor the ceilings have been finished, and there is no heating, light or electricity.

“I’ve retired since I started it, so I’ve run out of money,” Hedgecoe admits. Finishing the interior, which Alastair Brown, the selling agent at Strutt & Parker, estimates will cost £100,000- £200,000, will be left to the next owner, because the couple are selling up. “It’s an opportunity for someone to put their own stamp on the property,” Brown says.

Hedgecoe’s extension is the latest in a long list of changes made to Oxnead Hall, which sits in 13.6 acres of land nine miles north of Norwich, on the way to the fashionable north Norfolk coast. The original house was built in 1580 for Sir Clement Paston, an admiral for four Tudor monarchs and a scion of one of Norfolk’s most important families. Remodelled between 1631 and 1642 by one of his heirs, the property was at its grandest in 1676, when Charles II and his court visited. A new banqueting hall was built in their honour. A decline in the family’s fortunes led to the estate being sold in 1757, and most of the house was demolished. All that is left of the original is the former servants’ wing — a long, low building that is substantial in itself, given that the estate would once have employed some 650 staff.

It is understandable that Hedgecoe is running out of steam. When he bought Oxnead Hall in 1988, it was semiderelict. “But I liked the land and where it was,” he says. Once he had moved in, he set to. The house was habitable (just), but, as Jenny puts it, living in it was “existing rather than living”.

Hedgecoe installed a new kitchen and tidied up a bit before tackling the outside — then little more than rough ground used for keeping sheep and hens. At the front of the house, he planted a formal garden, with gravel paths and low box hedges, and yews standing sentinel at each corner. To one side was a long, low building that had been used for sheep; Hedgecoe added stone mullioned windows and intricate stonework to the roof, turning it into what he calls the orangery. He built a turreted folly on the banks of the river; and in the river itself, which was little more than a marshy swamp, he created a long, slim island, reached by mossy wooden bridges at either end.

Into the garden went a pool, and a separate pool house with three bedrooms. Later, Hedgecoe bought several piggeries at the back of the house, which he turned into studios (Pete Postlethwaite recently made a short film there).

So — setting aside the unfinished extension — what is Oxnead Hall actually like? The house has a slightly haphazard charm. It is essentially a series of rooms off a corridor, many of them interlinked — the kitchen leads to a dining room, which takes you into a formal drawing room, lined with books and with a deep window seat. More books cover the walls of the snug sitting room, along with bold portraits of fat ladies by one of Hedgecoe’s former students at the Royal College of Art, where he created the department of photography in 1965 and is now emeritus professor. He has written more than 30 books on the subject, which have been sold in 37 languages.

At the back of the house, the coach house and stables have been converted into studios and darkrooms. Filing cabinets line the walls — neatly labelled, they contain thousands of negatives. Pages from his books are pinned on the walls. Everything is slightly dusty; the smell of old books pervades the air.

Wooden staircases at either end of the house lead to the upper floor, with a bewildering array of rooms, all panelled, painted and filled with furniture, from carved four-poster beds to comfortable little armchairs. One bathroom has a jungly mural on one wall; in a bedroom, trumpeting angels, painted by Hedgecoe’s niece, flank the bed.

Everywhere there are paintings, line drawings, sketches — and, of course, photographs, although Hedgecoe doesn’t have any of his own on his walls. Instead, stacks and stacks of them are stored in one of the piggeries-turned-studios, almost all of well-known faces: here is the late Henry Moore, an old friend; there a large colour portrait of David Hockney, his face screwed up. “He doesn’t like that one,” Hedgecoe observes, chortling slightly.

The couple wonder aloud what they will do with the pictures, furniture and boxes of stuff once they leave, but quite apart from the problem of the extension — the house is just too big, and they want a change. “There’s just the two of us here — it needs more people,” Jenny says. They will be sad to leave: the house has played host to many guests, including David Frost, Malcolm Arnold and Sandra Blow, not to mention the children and grandchildren who have stayed in the three-bedroom cottage, also included in the sale.

Still, “One is tired”, as Hedgecoe puts it, and it’s time to go. Whoever buys Oxnead Hall may want to make to make changes, too — provided they can get them past the planners.

Oxnead Hall is for sale for £2.5m with Strutt & Parker (01603 617431, struttandparker.com) and Keys (01263 733195, keys-ea.co.uk)

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