A townhouse is a large, stately and luxurious house, also known as a mansion, which consists of at least two complete floors and an attic. Townhouses are seen as stately, large, decorated and spacious homes and are recognizable by the high gutter line and the high ceilings. They were mainly built at the end of the 19th century in the center of the town or village. In order to get the full potential out of the building, it is often necessary to demolish some later additions and to restore, renovate or redecorate most of the rooms in their original state or not. Townhouses require a lot of attention and knowledge in order to be able to properly analyze and optimize them. Because these are older houses with often more limited technical facilities and (much) lower insulation values, and because certain elements still want to be preserved, this house require a project-specific approach and a very good follow-up to answer the problems with the necessary professional knowledge or inventiveness. Depending on the heritage value, the condition of the property, the specific needs or wishes, it is possible to stay very close to the original situation or to mix with contemporary elements.