It is a widely held view that older buildings are not energy efficient and must be radically upgraded in order to improve their performance. In reality the situation is more complicated and assumptions about poor performance are not always justified. The challenge is striking the balance between benefit and harm, to both buildings and occupants. The solution is taking the ’whole building’ approach.
Understanding your building and how the building fabric and services work is key. Adaptations to traditional buildings, such as the closing off of chimneys, the use of impermeable renders and loft or cellar conversions all affect moisture movement, heat and ventilation, and may mean different strategies are required in different parts of the building. Similarly, location and orientation form an important part of understanding a building’s performance.
The condition of the building, and damp and drafts from poor maintenance, can also result in much higher energy use. Alterations, modernisation and poor maintenance can leave traditional building fabric at the limit of its capacity in dealing with water vapour or rain ingress, and the occupants with risks to their health.
Occupation and use are also a vital part of setting the aims of a retrofit. Understanding the history of use and how this has changed, is as important as making sure that planned retrofit measures are appropriate for both current and future occupiers of a building. Different occupants use energy in different ways. In most buildings the greatest energy use is for heating the building. However, office-based workers often use far more energy on appliances than heating. An elderly couple in their home might use hardly any appliances at all but have their heating on continuously. The energy use and cost-effectiveness of varying retrofit measures will, therefore, be highly influenced by the type of occupant as well as the use of the building.
Heritage and community must also be taken into consideration as part of any retrofit design. A building’s heritage may be indicated in planning terms such as Listed Building, Conservation Area or AONB, which all come with planning constraints. However, in many cases heritage value may not be formally designated and so an understanding of the street or even wider area can be useful in ensuring that the building can be enhanced by the retrofit without cost to its heritage value.
If you would like to read up in more detail about the Whole Building Approach, take a look at Planning Responsible Retrofit of Traditional Buildings (Neil May and Nigel Griffiths) which can be downloaded from the Historic England website.
