Explorer David Hempleman-Adams has thrown his weight behind Wiltshire St John Ambulance's campaign to raise funds for a new headquarters on the Hopton Industrial Estate in Devizes.

The charity, which has operated out of a listed building in Devizes High Street since 1987, is looking to raise £420,000 and is asking companies and members of the public to buy bricks on which their names can be engraved.

The bricks will cost between £35 to £200.

Mr Hempleman-Adams, who has climbed the seven highest peaks in the world, and was the first Briton to walk solo and unsupported to the South Pole, will be the first to buy a brick to place in the new headquarters.

He said: "St John Ambulance is always there for the people of Wiltshire so we really hope they will want to give something back and help us with this mammoth fundraising campaign."

The charity says its present home, St John House, is in need of major and costly refurbishment. It says the new building will be cheaper to maintain, better suited to the demands of modern technology and will comply with disabled access requirements.

Anna Farquhar, chief executive of Wiltshire St John Ambulance, said that it was hoping to get into the building in July or August and have it open to the public by September. The roof is due to go on by the end of March.

She said: "It is one of six buildings being erected by a property developer so it is not purpose-built, but it is perfect for our purposes. We will have training rooms and offices that will be bang up to date.

"We will be sorry to leave St John House but it is a listed building and costs an arm and a leg to keep maintained. It really is a white elephant.

"The whole project is costing upwards of £700,000. With the sum we have got from the sale of our former home, we still need to raise £420,000 but I have every confidence we are going to do it."