The Queen will today formally approve the work being done by an international award-winning ecological architectural practice in North Yorkshire.

Her representative, the Lord Lieutenant, Lord Crathorne, arrived at the offices of Eco Arc, in Harton, near Barton-Le-Willows, to confer on it the ultimate industrial accolade - the Queen's Award.

The firm earned the famous cut-glass bowl for "continuous achievement in CO2-neutral sustainable building design and development".

It will be entitled to fly the coveted Queen's Award flag and display on letter headings and in advertising the award winner's emblem.

Eco Arc's portfolio over the past 16 years has featured a host of new builds and conversions of housing, leisure and health buildings which turn them into energy-efficient units, producing their own water and power.

Architect Andrew Yeats, who co-founded Eco Arc chartered architects, at Harton Old Village School, with Lucy Nelson and Eric Parks, said: "This award will raise the profile of green architecture for the whole nation.

"To some extent our client based has moved. Previously our work tended to be confined to serving enthusiastic individuals or small community groups, but now our clients are more mainstream, including The National Trust, the Royal Horticultural Society and local medical practices.

"So this award is an endorsement that something very special is happening."

Typical of Eco Arc's projects was York's Environmental Education Centre, at St Nicholas Fields, in Tang Hall, which opened in 2000.

The energy-efficient building includes a green roof, wind turbines and photo-volteic panels which provide energy for lighting and computers, solar hot water panels, dry compost toilets and rainwater recycling schemes.