A genetic algorithm-based envelope design optimisation for residential buildings

National energy standards of countries worldwide require a wide range of measures to be used in energy policies. It has become a challenge to fulfil different measures of building envelope design optimisation through enhancement of energy conservation. To overcome this challenge, this study proposes an optimisation model for determining the optimum envelope design of a reference building in four climate regions. The optimisation model utilised a genetic algorithm, as an optimisation tool, and national standards to define the thermal insulation requirements of buildings for energy calculation. The building prototype was analysed to minimise the life-cycle cost (LCC), where building envelope elements – namely, windows, exterior walls, basement floor and ceilings – were included as energy efficiency measures. The results showed how each building element affects energy consumption in different climate regions. Exterior wall insulation was observed to have the maximum impact on the LCC of the whole building, which was followed by the window type selection. An optimally designed residential building was found to spend approximately 20–25% less energy than the limiting values expressed in the national standard. This paper highlights how the optimum design envelope for buildings in various countries and climates can be characterised by the use of the proposed optimisation model.