Heat Losses from Non-Repeating Linear Thermal Bridge and Impact on Heating Energy Consumption in a Typical UK Home

Non-repeating thermal bridging occurs at junctions when building components such as metal lintels cross from the buildings’ interior to exterior with little or no intervening insulation, creating a ‘bridge’ for escaping heat. In a 2006 building regulation compliant dwelling in the UK, the proportion of heat losses due to non-repeating thermal bridging is typically 10-15%. This can rise to 30% in better insulated low energy buildings. Limiting thermal bridging will therefore become increasingly important as more energy efficient buildings are being built due to the stringent requirements of current building regulations and the endorsement of higher levels by the Code for Sustainable Homes standard.The study has undertaken dynamic computer simulations to calculate the impact on energy consumption and to provide cost benefit and CO2 analysis for a 4-bedroom terraced house with Glass Reinforced Plastic (GRP) lintel and typical Steel lintel under London climate. Two-dimensional temperature and Relative Humidity (RH) distribution study has been carried out to find out the condensation risks.The paper presents that in terms of energy performance, a better insulated home with GRP lintels shows a better performance in energy consumption, CO2 emissions and energy bills. However, the most significant result of the reductions would be achieved by improving the building fabric. Moreover, the reduction achieved from installation of the GRP lintel has provided a further 10% energy demand reduction compared with the typical Steel lintel installation in the case study home. With regards to the condensation risk and the two-dimensional temperature and RH distribution study, the paper has shown that the GRP lintel could reduce thermal bridging significantly around junctions and at the same time help keeping dry the area around the junctions. On the other hand, Steel lintel would have high risks for condensation and it can also cause further health implications with mould growth on surfaces