Energy Efficiency and Older Houses
Older houses are often thought to be cold and draughty, but they can vary greatly in their energy efficiency depending on how they are constructed and maintained. There is growing evidence that many perform better than assumed, and some outperform modern houses in terms of energy demand and comfort.
These are the some of the key issues that affect the energy efficiency of older buildings.
A well-maintained older home will generally perform much better than one that is neglected. For example, badly maintained drainage (such as gutters and downpipes) can lead to damp walls. This increases heat loss through the wall, making the building much less energy efficient.
Older buildings need to breathe
A key characteristic of older buildings is the widespread use of 'breathable' (or 'permeable') materials, which are able to absorb moisture and release it again without damaging the building. By contrast, most modern buildings rely on materials that keep moisture out.
Maintaining the building's ability to control moisture levels in this way is fundamental to its effective thermal performance. When looking after or making changes to your home you therefore need to use materials that are compatible with it.
Older masonry houses were often constructed with thick external walls, as well as internal masonry walls. This type of construction can store warmth as the building is heated. The heat is then slowly released as the building cools down. As a result they can maintain a much more even temperature than much modern lightweight construction.
Another key issue to consider is ventilation. The majority of older buildings are made of porous materials that both absorb moisture and allow it to escape. Ventilation stops this moisture building up in any one place and causing damage and problems with condensation and mould.
However, too much ventilation can lead to a draughty and uncomfortable home. Draughts are particularly common at window and door frames, as well as at joints between different forms of construction.
Find out how to draught-proof your building.