The sensitive nature of most historic buildings means that all proposed works of repair or alterations to them need at least some degree of specialist knowledge.

Alterations or the construction of an extension to a historic building should commence with an understanding of the history, use and architecture of the building, from where a suitably designed scheme can be established. Inappropriate alterations and extensions to historic buildings can significantly detract from their historic importance and their general appeal and can sometimes even reduce the property's market value.

Inappropriate repairs to historic buildings using unsuitable methods of workmanship and materials can have disastrous effects and can potentially lead to many thousands of pounds worth of damage to a sensitive structure.

Most work to historic buildings requires specialist knowledge of materials, historic construction methods, legislation and possibly even taxation matters in order to organise and arrange for the works to be undertaken in the most appropriate and most cost effective manner. Inadequate knowledge and experience in any of these respects can result in unnecessary costs, possibly inappropriate and damaging repairs or, at worst, significant fines or even imprisonment in relation to contraventions of the legislation.