The complexity of finding solutions to reach energy sustainability in the built environment poses a significant challenge. Therefore, there is interest in adequate management of the generation, conversion, storage, use and exchange of heat and electricity. The novelty of this study exists in presenting and comparing multiobjective optimizations for operational CO2 emissions and lifecycle costs (LCC) of heat and electricity prosumers in the Netherlands and Finland, with and without net-metering. The premise relies on using surplus electricity to drive heat pumps for heat export instead of exporting surplus electricity. In the Netherlands, the calculated cost optimal solutions consist of using surplus electricity to drive an air source heat pump and export heat, with CO2 emissions and Delta LCC of -41.1 kgCO(2)eq/(m(2) a) and (sic) -69.7/m(2) (22% lower), respectively. In Finland, the heat export strategy allows a Delta LCC of (sic)-24.5/m(2) (8% lower), with CO2 emissions reduced by -32.5 kgCO(2)eq/(m(2) a). Without net-metering, the ALCC of the energy system rises to E-4/m2 in the Netherlands; with net metering, the ALCC lowers to (sic)-65.6/m(2) in Finland. The results indicate the potential for significant economic and emission reductions in heat and electricity prosumers.