Cubatures for Medium-sized Plus Energy Buildings

On the basis of dynamic building simulations within a maximal realistic framework, it may be useful with respect to the overall energy balance to dispense with pursuing a minimal surface/volume ratio of buildings—thus minimizing heat losses across the building shell—in favor of solar energy use. The specific use of the building (here: office or residential) plays a crucial role. Balancing the energy demand for heating and cooling and a possible photovoltaic yield, a surplus is possible in all cases under investigation. Long, low unobstructed buildings perform best due to large portions of roof area suitable for solar energy use. For tall buildings with less roof area, parts of the facades may be used for solar applications which makes them also perform better than compact designs. If the total energy demand including auxiliary energy for HVAC and especially electricity for the office and residential usages, respectively, is considered, compact cubatures of the size considered here (about 3500 m²) are not capable of providing positive energy balances. Residential usage performs worse than office use. Investigations are performed for the climatic conditions of Berlin, Germany.