Energy retrofit of the existing housing stock in England

by space and water heating. The high costs of energy are a national matter not only for their economic and environmental implications, but also because they contribute largely to a social problem, known as fuel poverty. The cost of heating the housing stock is rather high for different reasons, one of each being the heat loss through the building envelope. The thermal performance of existing buildings can be increased in two ways: by adding insulation to external fabric, and by reducing the unintended air leaks of the envelope. This study focuses on this second method, which can lower heat waste of about 20%.
Typical pre-1970 English buildings are characterised by an evident degree of permeability, emphasised either in the construction techniques or in the materials used. They are also pretty leaky: they have cracks and holes in the fabric, unused open chimneys and fireplaces, gaps around windows and door frames. Unwanted air leakage allows the waste of heat toward the outside and can cause interstitial condensation. As a result, there can be a decrease in the performance of thermal insulation (up to 70%) and fabric damages. Air-proof improvements increase the energy and cost efficiency of a building, raise the level of internal comfort and lower the risk of thermal bypass. They can be very cost-effective and easy to do, but their effects are underestimated. After draught-proofing, less heat will be wasted through the envelope (this can save on average £55 per year) and thus less heat will be required to have a comfortable temperature in the inside (this can save another £60 per year). The Energy Saving Trust (EST) evaluates that if every dwelling in the UK was draught-proofed at its best, £190 million would be saved every year and the unloosen energy would be sufficient to heat nearly 400,000 houses. The benefits from the economic, energy-efficiency, environmental and social point of view would be remarkable and worthy. After reviewing the literature on the topic, this work presents a case study, in which the most common air-leaking points are found in an existing traditional masonry solid wall house. Some easy-to-do and affordable recommendations are suggested to fix those points. Reducing air leaks is a sustainable way to improve thermal performance in dwellings; it is a relatively low-cost solution, with no big impact or negative effects on the environment, and it facilitates further strategies to lowering energy consumption and CO2 emissions.