Assessing energy use and overheating risk in net zero energydwellings in UK

This paper presents the methodological approach and findings of a simulation study of advanced energyconservation, generation and management technologies applied to two case study dwellings in the UK,so as to achieve net zero energy (NZE) target that includes a reduction of net regulated energy (HVAC)to 0 kWh/m2per year and energy generation of at least 50 kWh/m2per year. The performance of thedwellings are also tested for a change in energy use and risk of summertime overheating in future climatesin the short (2030s), medium (2050s) and long term (2080s).The findings indicate that to meet the NZE targets, regulated loads need to reduce by about half (overcurrent Building Regulations) with community (rather than building-level) renewables playing a majorrole. It is also found that the NZE targets, given current regulations, are not particularly difficult to achievein design with regard to energy efficiency but are highly expectant with regard to renewable energy. Fur-ther, summertime overheating is projected to be a risk for net zero energy dwellings by the 2050s. Despitethis the regulated energy use of both dwellings is projected to reduce by 11 kWh/m2/yr, accompanied bya small increase in renewable generation (2 kWh/m2/yr).