More humid climate

Mild and humid winters increase biological activity

The warmer and wetter winters of the coming decades will provide better conditions for biological activity. It affects the durability of building materials and the indoor climate.

As the temperature rises, the air can contain more water. Greater humidity can increase problems with, for example, mould and house dust mites, which have better living conditions. In our increasingly airtight houses, there may therefore be a need for better ventilation.

A milder climate can also mean that attacks from fungi, rot, and woodboring beetles will worsen. It will challenge exposed structures and building components, especially in organic materials such as wood and certain types of plastic, paper, cardboard, and paint. Choosing other materials for construction, surface treatment, and maintenance more frequently may be necessary. In some instances, it will be relevant to establish constructive protection, mechanical ventilation, dehumidification, or water drainage.

The ventilation rate prescribed in the Building Regulations will be sufficient in most cases. That is if the ventilation works. Hence it is necessary to regularly check that ventilation grilles are clean and that there is no blockage of free air flow in, for example, attic rooms. This regular check also applies to the ventilation openings at the eaves and both for natural and mechanical ventilation.