Ideal room temperature: living 20-21°C. Sleeping 15-18°C
Ideal relative humidity: 40 - 60%, < 30% too dry, >60% too humid: favours the growth of moulds)
Place your furniture 3-4cm away from the wall so that the air can circulate sufficiently here too (in this way you make life difficult for fungi).
Humidifiers (if needed at all): Use evaporator or steam devices (no atomiser devices) and clean them regularly: for humidifiers are a further source of fungi.
Air thoroughly but briefly 2-3 times a day.
Leave the window open while you sleep: every person gives off carbon dioxide. If the window stays closed, the carbon dioxide concentration in the bedroom slowly rises, which leads to a noticeable deterioration in the quality of the room air.
Make sure that electrical appliances (e.g. the clock radio) and installations such as cables and transformers are at least 2 metres away from where you sleep.
Smoking is indoor toxin number 1: make sure that nobody smokes in your home.
Use fragrance lamps and incense sticks in moderation. These too can lead to headaches.
Wherever possible, do without chipboard, or at least find out whether the chipboard has a quality mark (e.g. type V 100).
If you cook with gas, an extractor should be installed above the cooker to prevent exposure to nitrogen dioxide.
From a hygienic point of view, hard floor coverings (parquet or tiled floors, e.g. clay tiles) are preferable to carpets: carpets are ideal dust traps and often offer mites good living conditions.
Take care when shampooing carpets! In this way you bring moisture into the carpet (and not out again), which the mites particularly like.
If you nevertheless decide on a carpet, then have it stretched (not glued) in your room. This spares you what is in some cases a massive odour nuisance from the solvents in the adhesive.
Not everything that is biological is automatically healthy as well: for example, various paints based on natural resins are not harmless, particularly for people with allergies. Inform yourself beforehand.
Do without wood preservatives indoors; they are absolutely unnecessary.
Seek advice if you are planning a new building or a conversion. Prevention is better than cure!