The present study discusses alternative ways of achieving optimum energy efficiency for historic buildings in areas where sustainable energy projects are planned. About 25% of Europe’s building stock was constructed before the mid-20th century and despite EU’s strenuous efforts for the protection and conservation of historic buildings and complexes, achieving energy efficiency with the minimum or preferably no intervention remains as a requirement. The settlement of Monemvasia, has been selected as our case study. A model building was chosen, its special characteristics are presented, and four solutions to the energy efficiency upgrade of the building were tested: (a) the application of internal insulation, (b) a heat pump installation, (c) the application of roof insulation, and (d) the replacement of the internal doorframes. The four scenarios were simulated via the TEE-KENAK software and the percentage of the annual energy saved through the application of each one of the mentioned measures was estimated. The results proved that installing a heat pump and internal insulation would maximise energy savings. Coupling the energy demand of the settlement in correlation with a wind energy project in the wider area, and the available curtailment was explored. The results showed that if 300 houses decide on acquiring their electricity consumption from the local wind independent power producer, at a price of EUR 35/MWh, the possible profit from the market could reach EUR100,000 per year. Such a business-driven concept could be extrapolated and evolve into a holistic wind energy and historic environment symbiosis setting.