The gentrification of Birmingham's historic Jewellery Quarter could force manufacturers to leave the area, businesses have warned.

Rising costs and the influx of residential developments have put the quarter at risk of losing the trade which made it famous, according to its jewellery makers and experts from Birmingham City University (BCU), which runs a jewellery school there.

The quarter has become a magnet in recent years for property developers keen to tap into its historic architecture and ready supply of former factories - some in a severe state of disrepair - to create new residential developments.

Among the many examples are the conversion of the former Swan kettleworks in Icknield Street, an old biscuit factory in Caroline Street, now housing apartments and a small grocer, and the former AH Woodward pen factory in Legge Lane (see grid below for more).

Businesses claimed rent costs were spiralling and "inappropriate developments" were making it difficult for the district's traditional industry to continue trading.

One company owner has even said his firm might have to close if current trends continue.

They are now calling on council bosses to put measures in place to prevent the quarter becoming engulfed by residential accommodation and eroding what it called its unique culture and identity.

Greg Fattorini is the sixth generation of his family working for Thomas Fattorini, in Frederick Street, which makes items such as badges, medals and swords.

This former biscuit factory now has apartments, a beauty salon and grocery
This former biscuit factory now has apartments, a beauty salon and grocery

The family moved to the quarter in 1919 to be close to like-minded craftsmen.

"If nothing is done to manage what's happening, I'm concerned that we're looking at the death of the Jewellery Quarter as the pre-eminent centre for jewellery and related creative industries in the UK," he said.

"My concern is the integrity of the business cluster is being undermined by inappropriate property development.

"There is too little understanding of the Jewellery Quarter - I would like to encourage the developers to focus on other parts of the city which really do need developing.

"If it keeps on going like this, we will need to close our own business as it will become unsustainable."

Business owners say they fear the quarter will follow the same pattern as London's Covent Garden, which saw the loss of its traditional fruit and vegetable trade and is now best known as a tourism and shopping hotspot.

Beverley Nielsen, director of the Institute for Design & Economic Acceleration at BCU, added: "It's really important to make the invisible jewellery making visible.

"Not only is it our heritage but it employs large numbers of people across around 800 businesses.

The former Swan Kettleworks is being converted into new flats
The former Swan Kettleworks is being converted into new flats

"These function together and are interlinked and mutually supportive so that, if one or some of these businesses fail or disappear, the whole industry cluster starts to fall apart."

But the chairman of the Jewellery Quarter Business Improvement District told the Birmingham Post that some of the area's buildings were no longer fit for manufacturing purpose and would otherwise lay derelict if residential schemes were stopped.

Stephen Whittaker, also managing director of auction house Fellows, said: "What's happening to a lot of these older buildings is because they are no longer suitable for modern manufacturing because of new processes or changes in health and safety laws.

"And going back 200 years, there were workshops in the Jewellery Quarter with residential accommodation above them.

"There is a consultation committee which sees every planning application and makes its views known to the city council.

"We want to preserve commercial buildings for commercial uses but, unless we're flexible, derelict properties will stay derelict.

"Any area must progress. The Jewellery Quarter has a bright future in front of it and we're helping with workshops for young jewellers to stop them going to London."