Abstract The Isle of Eigg prides itself on not being connected to Scotland’s mainland grid and having an electrical network mostly supplied by renewables. The current island system was modelled using HOMER energy modelling software and the renewable output was commented on. The current systems renewable fraction resulted as 86.7%. It is not 100% due to the diesel generators that are switched on when renewable supply is low. With a new Community Centre currently under construction on the island, electric and thermal demand profiles were explored and its impact on the full network studied. It is shown to have a negative impact on the network as the diesel generator use increases by approximately 26%. The energy output from the generators rises from 41,691kWh/year to 52,733kWh/year and the renewable fraction falls to 84.6%. However, various technologies were implemented to either the building or the existing system to offset this new centre. Using a heat pump, thermal storage and other renewable adaptations resulted in the diesel generator power output falling by approximately 50% in respect to the currents system production. The renewable fraction of the entire network increased from 84.6% to 93.7% because of the adaptations. Hence, this investigation demonstrates that not only can a new buildings impact on Eigg’s electrical network be offset, but it can be utilised to help boost the sustainability status of the island.