Uncertainties in predicting the impact of climate change on thermal performance of domestic buildings in the UK

Abstract

Buildings typically have a long life span, which can easily reach 50 or 100 years. In the light of expected climate change it is therefore important to look towards the future, and to analyse how buildings will cope with the changes in climate that are predicted by the climatologists. In such long-term predictions of building performance, uncertainties play a large role. This paper describes a preliminary study that aims to better map out the consequences of dealing with a whole range of uncertainties in the specific case of predicting the effect of climate change on the energy use and thermal comfort (overheating) in the large stock of terraced houses in the UK. Uncertainties in climate change prediction are compared with other variable factors like building occupancy patterns, actual thickness of construction materials and HVAC control settings. Uncertainties have been propagated in a transient model of these terraced houses using the transient simulation program EnergyPlus. In order to explore the large range of input variants use has been made of a genetic algorithm. The current search and solution spaces are discussed, putting the impact of climate change in perspective with regards to other changes and developments that might increase or decrease overheating. Overall, the findings indicate that uncertainties in long term thermal performance predictions run high, with standard deviations of over 100%. However, the robustness of the contemporary dwelling design is fortunately high.

Climate change and future energy consumption in UK housing stock

“…The input parameter values were chosen carefully to make the simulation as realistically pessimistic as possible for typical dwellings and typical occupant behaviour but also to generate useful, interpretable results and therefore some compromises were made within the capabilities of the software. Research by de Wilde et al 8 has shown that although great uncertainty is involved in determining domestic energy demand, household energy use displays a normal distribution within approximately a 11-35 GJ/year total household energy consumption range, for the UK. Therefore to calculate a nationwide future scenario, a typical household demand for electricity and gas must be established whilst also identifying sensitivity ranges for key inputs.…”

Ranking of interventions to reduce dwelling overheating during heat waves

“…In order to achieve this, three options were considered. The first was to use a weather file from a European location such as Rome [24] or Milan [25] to approximate the South East England climate later this century. However, the different latitudes of these locations would affect solar shading calculations.…”

Adapting dwellings for heat waves

“…Some of the previous research identified has used climate data from warmer locations outside the UK, such as Rome [20] and Milan [21]. This allows the use of real weather files in the simulations, which are thought to approximate future climate conditions for the UK, assuming a medium high emissions scenario.…”