Campaigners have commissioned architects to produce plans for a new hospital central to St Albans, Watford and Dacorum.

West Herts Hospitals NHS Trust previously ruled out building a new A&E hospital for west Herts after being given a spending limit of £350million, but campaign group West Herts 21st Century Hospital Solution is going above their heads in an attempt to prove that a new hospital would benefit a growing population more than renovating existing services at Watford General.

They have commissioned architecture firm BDP Healthcare, who are working on plans for a new hospital, and are raising the money to pay the architects and associated experts through crowdfunding and donations from residents.

BDP has previously won awards for the hospitals they have designed in Birmingham, Sussex and Brighton, and are working on redeveloping a new children's cancer centre at Great Ormond Street Hospital.

Gordon Yearwood, who is heading the campaign, said: "It is an enormous privilege to be working with BDP on this. They have amazing credentials, and with their 21st-century hospital plans we will demonstrate to the Dept of Health that a new hospital is not only possible, but is the only long term and sustainable solution for this area.

"Look at the work BDP have done across this country and abroad, delivering world class hospitals. Why should we, in west Herts, be treated so shoddily that we have to make do with a hospital that fails on so many levels?"

The campaign group also criticises the imposing of the £350million spending limit.

Gordon said: "They have wilfully disregarded the needs of all of us who live in the area, citing only 'affordability' as the reason we cannot have a new hospital.

"If they are given the £350 million they are asking the government for, they will squander it on piecemeal repairs and refurbishment at Watford, they will have very little left for St Albans and Hemel Hempstead, and they will continue to run at this appalling deficit, which taxpayers have to pick up every year. We want a new hospital that comes within its budget every year. Most importantly, we want a great hospital for patients and staff."

The campaigners have raised more than half of the £38,000 they need to pay the experts, and do not yet have an estimated cost for a new hospital but believe it would cost less than the £700m to £750m the trust claimed.

Andrew Smith, head of healthcare at BDP, said: "Hospitals can be stressful and intimidating places, but we know that better environments secure better health outcomes.

"Healthcare buildings are the places where many of us will experience life's most profound events, and yet they are also complex technological facilities which have to operate efficiently.

"Our designs pay close attention to clinical effectiveness and efficiency but they always prioritise people- patients, their visitors, and the staff who care for them."

The campaigners have asked the architects to produce a plan which could be adapted for any site, but say several sites are available and could be suitable.

Gordon said: "Time constraints mean that BDP are already at work on our behalf. We have to get our plans into government commensurately with the Trust submitting theirs in July. We are asking people to support us, as we need more funds for the BDP plans.

"It is very exciting to have reached this stage, to actually work with some of the best architects in the world."

The West Herts Hospitals Trust (WHHT) has continually defended its decision to renovate Watford General.

A spokesperson said: "Due to constrained public finances we need to revise our initial strategic outline case, which was based on funding of up to £650m, and instead look at funding of closer to £350m.

"This is still a considerable sum of money and we are looking at various options for using this to transform hospital provision locally. However it is not enough to build a new general hospital. Our costings show that this will cost upwards of £700m."

Donations to the campaign can be made at crowdfunder.co.uk/west-herts-21-century-hospital, or into the group's bank account: West Herts 21C Hospital Solution, Lloyds Bank, sort code 30-90-99 , account number 28468468.