A new million-pound hangar is to be built at an aircraft museum which will enable it to expand its range of facilities.

Hertsmere Council gave the go ahead for the large hangar at Britain’s oldest aviation museum at Salisbury Hall in London Colney.

The decision was welcomed by jubilant directors and volunteers at the de Havilland Aircraft Heritage Centre as the key to its ambitious development plans.

Operations director, Ralph Steiner, described the planning decision as “tremendous news” and said that the trustees had decided that in future the centre would change its name to the de Havilland Aircraft Museum to reinforce its main purpose of restoring and displaying historic de Havilland aircraft.

He went on: “First and foremost the new hangar will enable us to get most of our vulnerable aircraft under cover.

“De Havilland produced aircraft from 1910 to the 1970s and we have some unique aircraft which it is crucially important are preserved for future generations to come and see.

“We have been developing our plans for several years and it is absolutely vital that we get more of these aircraft undercover as they are not all made of metal and being exposed to the weather can lead to all kinds of damage and corrosion.”

The new hangar will nearly treble the amount of covered space where the aircraft can be put on display. It will have a mezzanine floor, an enhanced de Havilland information and educational area, workshops for restoration work and a refreshments area.

It will replace a small corrugated iron Robin Hangar more than 80 years old and will abut and dwarf the centre’s other, large hangar built some 30 years ago.

The new hangar will have a climate-controlled environment and is the second stage of the museum’s development plan – early last year a new reception foyer and aeroshop were created at the centre.

It is the only museum in the world where there are three examples of de Havilland’s “wooden wonder”, the Mosquito fighter, bomber and prototype.

Mr Steiner said: “The museum is anxious to upgrade its facilities and enhance what it offers to its many visitors and we need to raise a further one million pounds to complete the building.

“Our aircraft are of course the focal point of the museum, but it is important that we provide good facilities for all visitors, families, enthusiasts and school and youth groups.”

The new facilities mean more volunteers will be needed to help run the museum as well as maintain and restore its aircraft.

Details can be found on the website www.dehavillandmuseum.co.uk