“Inquiries went up, viewings went up and it sold very quickly,” says Berry

The house had been on the market at £630,000. With the new plans and images,
it went back on the market at £710,000 and sold for £699,000.

“We envisaged an extension which provided a utility room on the ground floor,
a bedroom above and pulled out the roof to create two gables which made much
more space inside.” He estimated building costs at £75,000 to £80,000.

Sellers are increasingly letting the pictures tell the story. A decade ago,
computer-generated images (CGIs) were used solely by developers, and were so
bad that private home owners didn’t want them anywhere near their sales
brochures. Now some are so good that it is hard to distinguish them from
actual photographs.

Houses undergoing change have particularly found that CGI is their new best
friend. Charles and Pamela Smith live in a bungalow called Orchard Close,
which was built in the Fifties by Charles’s father in St Cross, a
sought-after area of Winchester.

It is surrounded by beautiful listed buildings and for years they thought the
bungalow could be replaced by something more attractive. Finally, they asked
George Saumarez Smith, of Adam Architecture, a practice with a reputation
for classical design, to draw up a house like an 18th-century gentleman’s
town house.

The new house will have a stucco front, flint-and-brick rear, three bedrooms,
terrace, and permission for another bedroom suite in the basement. It comes
as an oven-ready package, and pin-sharp CGIs to show exactly what it will
look like. Knight
Frank (01962 850333) is selling at £850,000, and the building work
is likely to cost about £400,000.

“Selling a planning permission is different to selling an existing house,”
says Charles. “You have to be able to transfer your passion and vision to
the buyer.” The CGIs were produced by a Bristol firm, Architecture
in Motion.

“We thought for a long time about what sort of house would be suitable, and
getting planning permission was tricky, but we like what we have come up
with very much indeed,” he says.

Sometimes plans and constraints combine to form solutions which are so clever
that it is almost impossible for buyers to imagine.

Yaffle Hill, in St George’s Hill, Weybridge, Surrey, is considered such an
iconic house that attempts to adapt it to meet the demands of today’s
high-net-worth buyers involve plans for a sunken glass cube which doesn’t
spoil the original house and is connected to it by an underground passage.

The house was built during the First World War by W G Tarrant, who conceived
the whole estate. It originally had 24 bedrooms and servants’ quarters, set
in 20 acres, but was later divided into three and this is the principal
wing.

It was used in the original Tarrant brochure for the estate, which has become
one of the most expensive addresses in the country. The plans have the
blessing of English Heritage but do not yet have planning permission from
Elmbridge Borough Council or the St George’s Hill Estate.

The new glass-wrapped extension will contain a dining room, drawing room,
family room, cinema, kitchens, staff quarters, swimming pool, spa, sauna and
gym on two floors, almost doubling the space. Savills
(01932 838000) is asking £3.85 million.

Reshaping the interior of a house, pushing down and digging out, is not unlike
doing a Rubik’s cube, so CGIs are there to help the puzzled buyer.

A large Victorian gothic six-bedroom house on Spencer Park, Wandsworth, south
London, is a good example. It has direct access to a private park, which has
a tennis court, gardens and walks, and is used only by residents with gates
connected to it. The house has been in the same family for 30 years but
buyers now demand a lot more than the Victorians left behind.

Paper Projects Architects has found space in the ground behind the house to
make a huge family room, cinema, pool, gym, cinema and maid’s room. Savills
(020 8877 1222) is asking £6.5 million for the house with the plans but
without planning permission.

Clever images slice through the house like a four-tier cake, showing the
gymnasium lurking like a submarine beneath the garden, complete with running
and rowing machines, just waiting to be used.