THE iconic image of the Yorkshire Dales landscape would be nothing without the presence of ancient field barns - some 200 years old.

They are as much a signature of the Dales environment, ecology and agricultural heritage as the peaks and fells which tower above.

It is said there is something in the region of 6,000 such buildings in the national park in various states of preservation. But nobody actually knows.

So a company, which focuses on sustainable planning and design, Ecovril, has put together a document which calls for a concise scientifically-based survey to reveal the number and condition of these stone buildings on a specific date.

It proposes the production of a modern Domesday Book of barns, a challenge which will involve surveying each and every one of them.

The idea comes as the Yorkshire Dales National Park is considering new policies which could make it easier to develop some barns to new uses, in an effort to safeguard the future of the buildings.

Some believe the need for septic tanks, mains electricity, access tracks and the remoteness from amenities would make the development of most field barns unsustainable.

The national park has welcomed the field barns survey and are prepared to talk about taking the issue further.

Peter Stockton, the park's head of sustainable development, said: “We have a lot of information already from our Dales Volunteers, who have been surveying barns and historic buildings, and all that is in our Historic Environment Record, which is available to the public.

“However, we don’t have a comprehensive survey in the pipeline because the scale of the task is so great – we estimate there are about 6,000 traditional stone barns in the national park. If someone is prepared to do a survey then we would welcome it and we would be happy to talk to them about it.

"We are in the process of developing new policies that will make it easier to convert barns for new uses.”

One of the authors of "The Yorkshire Dales Barns Domesday Survey " is Andy Singleton, of Ecovril, who is also the joint author with David Joy of "Barns of the Yorkshire Dales" He stresses that the document is a proposal only.

Mr Singleton said : "Our idea is not to come up with a solution. What we are suggesting is providing a starting point. We' want an informed debate based on scientific information.

"The survey will tell us where these barns are and what is their condition, so that if we come back in ten years time we will be able to see if their condition is worse or better.

"My view is that if we don't use these buildings we will lose them. We need modern solutions which will create incentives to repair them. A working countryside is the one that gets looked after - we don't want to see the landscape as a museum."

Taking positive action could lead to funds being provided from local or national government or the EU for the preservation of the buildings as a monuments, the law could be changed to compel owners to repair and protect them through listing, it could stimulate ideas for creative change of use backed by strict planning controls and it could lead to grant funding.

Inaction would jeopardise the chance of the buildings being rescued for future generations, and many were reaching the point where decay of roof structures and lack of drainage systems was resulting in collapse, he said.

A supporter is Colin Speakman of the Yorkshire Dales Society , who has sympathy with the document's call to bring barns back into use.

He said: "The stone barns of the Yorkshire Dales are a unique and precious part of the Dales landscape, but we can only protect those that have a use and purpose.

"Ecovril's suggested Doomsday survey is an important first step in delivering a strategy which can help conserve and bring back into hopefully productive use at least the most visually and architecturally significant examples of these historic barns, as part of a living Dales heritage."

The designers estimate it would take two years to complete the survey and cost in the region of £120,000. It was hoped to raise the cash partly from the national park, from various appropriate grants and private and corporate donations.

It would be carried out by a number of teams led by a qualified, experienced leader. Among the team could be students of architecture and other similar disciplines and volunteers. The aim was to start in June this year.

Permission would be needed from landowners and all the surveyors would have to carry identification and proof of authorisation to undertake the work.