Cape Town - A frenzy for inner-city residential property has hit Cape Town, and architects believe it will give the city back its "verve", possibly returning it to the glory of the 1950s.

The flurry of demand for inner-city living was sparked by the recent conversion into 178 luxury residential apartments of a Cape Town landmark: the Old Mutual building in Darling Street, which was built in 1939 and is recognised internationally as an art deco landmark.

Old Mutual battled to attract corporate interest and was toying with the idea of mothballing the building but came up with an alternative plan.

About two weeks ago all the apartments were sold in one frenzied weekend, architect firm Louis Karol Architects (LKA) said on Friday.

LKA is converting the building into residential living space.

"The building sold out in two days flat," said Louis Karol, a partner at the firm. "It was the start of a fire, unleashing more demand.

"Old Mutual was the spark that lit the fire which, I predict, will become a raging inferno."

The cheapest apartment was sold at R7 000 a square meter, while the most expensive went at about R19 000 a square metre - all to South African buyers.

The buying frenzy over Mutual's converted family jewels comes in the wake of Irish investors earlier this year purchasing BoE's former offices in Wale Street, partly for residential purposes.

Plans are now afoot to convert four more office blocks in the city centre into residential living.

Karol was involved in negotiations that included a residential proposal for a major skyscraper in Long Street, although he said this had not yet been approved.

Another firm of Cape Town architects is also involved in talks.

Karol pointed out that the residential component was the key to converting the inner city into a vibrant, 24-hour urban centre.

"The central city will never be the shopping mecca of Cape Town anymore [as it was]," he said.

"We will never be a New York or London, where central city shopping is good because there are 1 million tourists a day."

However, the spin-off of residential inner-city living included more restaurants, music and clubs, attracting tourists at night and thereby harnessing Cape Town's economic strong point - tourism - to its fullest effect. Karol said: "The ball is rolling.

"I predict that in five years Cape Town's inner city will be a fascinating, 24-hour, vibrant city, supplementing the Waterfront."