Low Energy and so-called Passive Houses (LEH and PH, respectively) represent innovative design and technologies implemented in favour of energy efficiency. Compared to a standard house, both of these housing types have increased window surface area facing south, increased insulation on both walls and windows, sand-lime brick replacing the traditional bricks. The general description of the housing types is provided in the Glossary, while the list of parameters defining the houses in the model is provided in Supplement A.
The difference between LEH and PH is mostly a question of degree of efficiency: insulation is better in the PH and therefore the total heat demand of the same-sized house is much reduced. To match this high level of efficiency, an electric heat pump is the desirable choice, while in the LEH the best available fossil fuel-based heater, i.e. the gas condensing boiler, is implemented.
In Case Study 2, the gas condensing heater was compared to the heat pump inside the LEH. In the present case study, the comparison is between the two houses with their standard heating system, i.e. gas condensing boiler for LEH and heat pump for PH. In addition to comparing different heating technologies, the case study also endeavours to assess them using different grid mixes.