Proposals to improve and upgrade Ipswich Museum have taken a huge leap forward – with the scale of the project set to double.

The borough council had been planning a £10million upgrade for the High Street site, but after an initial assessment by outside experts, it is now looking at creating a £20m “High Street Campus.”

This would link all the arts’ buildings in the area, including the Wolsey Studio Theatre, the Ipswich Art School and the High Street Gallery, to the historic museum with an indoor “street.”

It would also create a completely new office and conservation block – and enable much more of the council’s heritage collection to be accessible to the public.

If a funding application for half the cost to the Heritage Lottery Fund and the Arts Council is successful the revamped museum could be open by early 2019.

The whole area will be transformed. A new main entrance will be created between the current entrance and the High Street Gallery.

The area that is currently open will be covered by a glass roof and will include a cafe and shop – the idea is that the cafe will attract visitors who do not necessarily want to visit the museum.

A new office and conservation centre would be built on the site of the current staff car park – a major step in increasing accessibility to the collection. Conservation staff will have workshops that are glass-sided, giving the public the chance to see them at work.

At present only about 10% of the borough’s art and heritage collection is on display at any one time.

The revamped museum will allow 30% of its collection to be displayed – and a further 30% will be available for view to anyone who requests it.

Improving the museum will also make it easier to manage – and should cut heating bills and make it easier to keep items in atmospherically-controlled conditions

The museum currently attracts 45,000 visitors a year. By expanding it and linking it with the other heritage sites, it is estimated it would attract another 50,000 visitors a year – mainly from outside the town.

It is estimated that could bring in near £2m a year in extra spending to the town. It would also help to redress Ipswich’s tourism imbalance.

It is estimated that only about 10% of Suffolk’s tourism spend comes to the county town – a very low figure given the population of the urban area.

Ipswich Borough Council culture portfolio-holder Bryony Rudkin said the proposed development of the High Street would be a major step in improving the town’s cultural offering.

She said: “The museum is a much-loved building and we are very keen to retain its great atmosphere but it is looking a bit tired.

“There was some work in the 1950s, but there have not been major changes to the building since it was put up by public subscription in the Victorian age.

“We want to really take this on and create a real attraction that will bring people from a wide area to the town.” She said the council would be looking to get about half the £20million cost from national bodies.

“We will be bidding for about £8million from the Heritage Lottery Fund and £2m from the Arts Council.

“The rest will come from other sources – some from the council and then from other donations. But the appeal to buy the Ipswich Art School was very successful and we hope to repeat that on a larger scale,” she said.

Ipswich MP Ben Gummer helped to develop the Arts School for the town and welcomed the move.

He said: “I am delighted that the Colchester and Ipswich Museums Service is pressing ahead with this proposal. Our town’s museum is a real asset for Ipswich.

“I was excited to be part of the Art School Project and I am thrilled that this ambitious proposal is now going forward – it is just what Ipswich needs.”