We've put together some guidance on common work carried out on listed buildings. You will need listed building consent for any work which changes the character of the building, but not for repairs and general maintenance. Damp Damp is often misdiagnosed in historic buildings. You should try to find and treat the cause of the problem, not just the symptoms. The most common source of moisture is faulty ground and surface drainage, which can be found in nearly every building. Historic England recommends that a survey is carried out by an independent professional, such as chartered surveyor, to assess the causes of the problem and how to treat it. Historic England have more information on understanding decay in buildings, including how to spot potential problems. Brickwork and repointing You should match existing bricks and mortar. Repointing will need to use a traditional lime-based mortar. Cement-based mortar will damage older buildings as it stops the walls from ‘breathing’ which can cause damp. Original uncovered brickwork should not be rendered or pebble dashed. See Historic England's guidance on repairing external walls. Rendering and plastering Render is a decorative layer of plaster that protects the wall from the weather. You should use the same mix and strength of render for repairs as the render already on the wall. Hard cement-based mixes should not be used as they create a waterproof barrier that prevents any moisture in the wall from evaporating. This can cause damage to the building. Roofing Natural Welsh slate is recommended for historic buildings. Some imported slates may be suitable, but these must be checked by us for colour and quality before use. Find more advice on repairing slate roofing. Replacing a thatched roof on a listed building must be done with long-straw thatch. The Society for the Protection of Ancient Buildings (SPAB) has more information on thatched roofs. Windows and doors Non-traditional materials such as plastic (uPVC) and aluminium windows must not be used in historic buildings. Double glazing is not normally allowed as traditional sash and casement windows cannot easily accommodate double glazing units. Instead, you can improve insulation and reduce noise by draught proofing and fitting secondary glazing behind the original windows. Find more guidance on windows on SPAB's website or download Historic England’s guide to the care, repair and upgrading of traditional windows.