This paper presents an analysis of whole-building performance modelling and simulation process of a low-energy single-family detached residence located in Northeast US A total of six design alternatives are modelled with EnergyPlus to predict relative performance improvements associated with a diverse set of energy efficiency measures of both building envelope assemblies and unconventional HVAC systems with inclusion of on-site renewable energy technologies. Simulation results indicate 29.3% energy cost savings (with respect to ASHRAE 90.1 2004 Standard Model) achieved through envelope efficiency measures only and 49.1% savings through coupling with a complex HVAC configuration and renewable energy systems.