In some circumstances, sacrificing a parcel of land can be the only way to save your house and thus preserve a piece of 700-year-old history. Princess Olga Romanoff owns Provender Manor, a 29-room Grade II* 14th-century manor near Faversham in Kent. But although she is a descendant of the Russian royal family, that lineage does not confer wealth, so she is selling a slice of her 37 acres. The two-acre site has planning consent for five houses and is for sale for £750,00 through the estate agent Humberts.

Under a scheme devised in collaboration with English Heritage, the money raised will go towards restoring her dilapidated and, in some places, near-derelict property. About £1 million needs to be spent on the roof alone. “I am desperate to keep the house,” she says.

That attachment is part sentimental: her great-grandmother rented Provender Manor from 1882; her grandmother then bought it in 1912. Her grandmother, whom Princess Olga calls a “terrible snob”, drew up a list of the house’s most well-born former inhabitants that hangs by the grandiose but mouldering front door. Provender was said to be the hunting lodge of Edward, the Black Prince; James Edward Austen, one of Jane Austen’s brothers, also lived there.

But a certain obstinacy of character also seems to motivate Princess Olga’s determination to fight for the house. At the death of her mother — who was married to Prince Andrei Romanoff, nephew of Tsar Nicholas — Princess Olga was advised by her lawyer not to stay on in the property. This made her doubly resolved to ensure its continuation for her three children, although single-minded dedication to the property seems to pass through the female line of the family. Alexandra, her daughter, will assume the responsibility of Provender, rather than either of her two brothers.

Fortunately for Princess Olga, Ptolemy Dean, the architect made famous by BBC Television’s Restoration programme, has also become involved in Project Provender. He has already renovated one wing of the house up to a standard approved by Princess Olga — which means not too scrubbed and nouveau. The degree of limewashing of the exposed timbers seems to have been a subject of lively debate.

Dean, an ancient-ruins specialist, has also designed the homes to be built on the land being sold off. The five houses that have planning permission for the site will be built in brick and tile, the Kentish vernacular.

Provender Manor’s black and white half-timbered exterior is particularly in need of the care and attention that the proceeds of the land sale should make possible. This façade was revealed sometime in the 1920s when a Georgian frontage became detached after a series of storms. Princess Olga’s grandmother arranged for the lime plaster to be smartened up with cement, a material whose lack of porosity has caused significant damage.

The problems with the roof started in the 1980s, when the guttering fell down and was not replaced. The leaks mean that there are buckets everywhere: fading grandeur would be too kind a term for the decor. But this extreme form of shabby chic has a certain appeal, which means that Princess Olga is able to hire out rooms for events. When I went to meet her, the catering company was collecting the tables and chairs after a dinner for the European Boxwood and Topiary Society. She also takes paying visitors on tours of the house — where a hard hat is not necessary. Such enterprises will help to pay repair bills; there may even be weddings at Provender.

Princess Olga’s clipped commentary on my tour of the house ranges from an Elizabethan fireplace, covered over in the Georgian era, a room lined with 17th-century panelling, her childhood schoolroom along a dusty corridor, to her family portraits. She points to a snapshot of a noble but pugnacious-looking Imperial Russian and remarks: “My uncle Prince Yusupov, one of the people who murdered Rasputin.”

Decay and deterioration may have met their match in this Kentish member of his clan. Humberts, 01233-740077

Fact box

Greg Clark, Tory MP for Tunbridge Wells, has proposed a Bill to remove gardens from the definition of brownfield land.

The Bill was due to be heard in Parliament last Friday but has been postponed until October 19 this year.

The proportion of homes built on previously residential land in England in 2006 was 18 per cent, the Department for Communities and Local Government says. That compares with a figure of 11 per cent in 1997.

For the South East, the proportion has risen from 16 per cent to 29 per cent over the past ten years.

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