Building materials and construction methods

Solar radiation through windows can be very important (especially in summer), particularly if buildings have large window areas. External solar shading systems should be provided to ensure a comfortable room temperature. External sun protection is significantly more effective than internal sun protection.

• Fixed solar shading: Existing solar shading.
• Mobile sun protection: Roller blinds, window shutters, sun protection sails...

The thermal envelope of a building is the surface that separates the heated interior volume of the building from the unheated environment. Heat loss occurs around this envelope. The heating demand depends on the insulation quality of the thermal building envelope. Ensuring continuous insulation is of great importance here.

Insulation of walls can be done either from the outside or from the inside. Insulation from the inside is only recommended if insulation from the outside is not possible, as insulation from the outside has many advantages:

• If a few rules are followed regarding the application of insulation, there are almost no moisture-related dangers to the structure.
• The walls can store heat. Consequently, walls cool down more slowly in winter and reduce temperature fluctuations inside the house. In summer, they in turn reduce the heating of the house.
• The temperature on the surface of the walls increases and improves the feeling of well-being.
• Reducing thermal bridges.

Old buildings often have façades that are worth preserving because they have surrounds or other decorations made of sandstone. To preserve the visibility of these decorations, insulation from the inside should preferably be chosen.

Good air tightness is important for the following reasons:

• Reduction of noise penetration from the outside.
• Reduction of energy losses
• Reduction of odours from outside
• Reduction of mould problems
• Reduction of draughts, etc.

Even for existing houses, it is important to ensure good air tightness. In the context of energy renovation works (replacement of windows, insulation of the roof, ...), the improvement of air tightness plays an important role.

Afterwards, sufficient air exchange must be ensured, either by opening the windows or by a central or decentralised ventilation system.

Windows have several tasks:

• Solar radiation
• Brightness of the house
• Triple glazing: better acoustics, greater comfort

Ensure an airtight installation.

Use of solar energy - the rays of the sun enter the interior of the rooms through the windows and help to warm them up.

In some cases, the installation of a ventilation system should be considered during the energy renovation of a house, as it:

• reduces CO2 levels

• eliminates the humidity released in the house (residents, animals, kitchen, WC, showers/bathrooms, plants,...)

• removes the humidity released in the house (residents, animals, kitchen, toilet, shower/bath, plants,...)

• Saves energy

The air is extracted in the humid rooms (bathroom, kitchen, WC,...) and blown into the other rooms (living room, bedroom,...).

There are 2 main types of ventilation systems: the centralised and the decentralised systems.

Central system: The entire volume of the exchanged air (supply of fresh air and removal of exhaust air) passes through a central heat exchanger.

Decentralised system: Independent units with or without heat exchangers are installed in each room and do not require a ventilation duct network.

The roof can be insulated from the outside, from the inside or between the rafters. Depending on the thickness of the insulation to be installed to receive the subsidies, the insulation is installed either from below or above between the rafters and the rest, or between the rafters by doubling them up.

It is important to also insulate those building components that are connected to unheated rooms. If there is no insulation, you will heat the unheated rooms indirectly. The insulation is usually installed from the basement without major problems.

 Heating requirements

Every building needs a heating system regardless of its insulation quality. The heating capacity and the energy demand depend on the insulation quality.