ENERGY-EFFICIENT RENOVATION OF HIGHRISE HOUSING

The study aims to inform designers about a method for assessing the li kely energy consequences of decisions open to them regarding refurbish ment options for high-rise housing in the UK. The TAS degrees thermal simulation computer program was used to predict the effects of various improvement measures for a first-floor and a tenth-floor flat. The pe rformances of retrofitted thermal insulation, double glazing, ventilat ion control measures, and sunspaces were considered. A lifecycle costi ng method was used to indicate the energy and financial benefits of th ese improvement options. The results indicated that there was a differ ence of between 25% and 60% in the predicted heating loads of the firs t-floor and tenth-floor flats, depending on the improvements installed . Ventilation control measures were found to be the most effective in reducing heating loads and to have progressively greater significance the higher up the building the fat is located. Conversely, wall insula tion measures were shown to be the least effective in view of the rela tively high percentage of glazing within the external wall areas. The predictions indicated that the provision of sunspaces could not be rec ommended solely on energy-thrift grounds, because of their high capita l costs and low energy savings, but other improvements could be justif ied over the lifetime simply by taking account of the cost benefit of predicted energy savings. The interaction of the effects of various re novation measures was also considered. Surprisingly, several envelope- insulation measures installed together can save more than the sum of t heir individual savings, the reasons for this are discussed.