At the time of writing there is general change in National Planning Policy for the Historic Environment, The National Planning Policy Framework (NPPF) guidance for listed buildings with thatch is brief – “existing thatch should be replaced with like for like material unless a strong case can be made for change.”
English Heritage’s guidance documents clarify
A flexible policy towards the choice of thatching materials and styles in no way compromises “traditionalists”, who do not wish to embrace change. However policies should also allow those who wish to make professional judgements for change to do so without fear of reprisal. The UK is fortunate to have such a rich thatch heritage. It is thatchers who take the responsibility for the durability and quality of their workmanship. With thatch an approach to heritage of constructive conservation is the key to its long term survival. Indeed government policy defines conservation as the intelligent management of change. To this end thatch and thatching must be allowed to evolve using the very best current materials and methods necessary for its continued survival. In conservation terms, respect for the past is necessary, consideration for a viable future is essential.
Members of the National Society of Master Thatchers (NSMT) endeavour to work in conjunction with local authorities to realistically balance conservation principles, historical accuracy and the demands of modern usage of old buildings, which includes a duty of care to provide a high level of craftsmanship and a sympathetic and flexible approach relevant to every property in their care.
CODE of PRACTICE – DUE DILIGENCE
It remains a thatching fact, that there are no nationally agreed industry minimum standards. It is really important for the survival and appeal of thatch that this situation prevails. How a particular style of thatching is carried out is not part of NPPF guidance. It would be a disaster to the industry if this situation were to change.
All NSMT thatchers will make decisions regarding the care and maintenance of a listed building using their professional skills. Their evaluation of existing thatch will consider the current condition of the property and past performance of the thatch.
Availability of acceptable quality raw materials will be judged and documented against specifications required through the Thatchmark quality programme. An assessment of the condition of a property might recommend a change in materials or material preparation techniques or replacement of other roof elements where to do so would be in the best long term survival strategy for a property.
Thatchers accept that in many cases concerning listed buildings, care is taken to protect the original fabric of the building in addition to the thatch for the very reason that it is of historic interest. However, a thatched roof had no characteristic of permanence when it was first installed and was installed with the view to its frequent replacement. Thus the replacement of the thatch is (and was always intended to be) part of the continuing history of the building. Where ever possible it is only the surface layer that is replaced. The appearance of the thatch will change over time, in the same way that the surrounding area will develop and change.