The energy balance of a building consists of making an inventory of all the energy supplies to the building and identifying the uses of this energy within the building.
The energies analyzed can be of different natures such as fossil fuels, electricity, biomass, heat/cold…
Then the consumption of these energies is classified by type of use:
- Consumption for secondary energy production
- Domestic hot water
- Mechanical ventilation
- Specific electricity
To be even more stringent, it is possible to associate to each flow the energy content of the natural resources mobilized: this is the primary energy balance. All energy losses associated with the production of resources (extraction, processing, transmission and distribution) are then recorded.
Thermal inputs come from different sources:
- Internal heat inputs into the dwelling, such as the presence of occupants or the operation of household appliances
- Solar gains also contribute to heating the home and are therefore part of the heat gains in a building’s energy balance.
In an uninsulated building, the heat inside will tend to escape. According to ADEME:
- 30% of heat loss is through the roof
- Between 20 and 25% through the walls
- 7% by the floor
- 13% by the glazing
Energy simulation tools
These tools are used to simulate the thermal behavior of a building. There are dynamic simulation tools or simplified tools. One of these simplified tools is the PHPP (Passive House Planning Package) software aimed at the design and certification of passive buildings.