We breathe around 15,000 litres of air every day. Roughly 20,000 breaths, most of them taken indoors, in our homes, offices, and the spaces where we spend the vast majority of our time. Yet the air inside these rooms rarely gets the attention it deserves. We choose paint colours with care and agonise over furniture placement, but the invisible atmosphere filling our rooms often goes unconsidered.
A few key concepts can help you make choices that genuinely improve the air you and your family breathe. No science degree required.
What’s Actually in Your Indoor Air?
Indoor air contains a complex mixture of gases, particles, and biological matter. Some comes from outside: pollen, traffic emissions, dust. But much of what we breathe indoors originates from the materials and activities within our homes.
VOCs (volatile organic compounds) are chemicals that evaporate from liquid or solid materials into the air at room temperature. They create that distinctive ‘new paint smell’ or the scent of fresh furniture. Some dissipate within days; others continue off-gassing for months or even years.
Common indoor VOC sources include paints, adhesives, engineered wood products containing formaldehyde-based glues, cleaning products, and some textiles and carpets. At high concentrations, VOCs can irritate eyes and respiratory passages, trigger headaches, and affect concentration. Long-term exposure to certain compounds raises more serious health concerns.
Beyond VOCs, indoor air may contain particulate matter (tiny suspended particles from dust, cooking, or outdoor pollution), carbon dioxide (which builds up in poorly ventilated spaces, causing stuffiness and reduced alertness), and excess moisture, which can encourage mould growth.
How Materials Shape Your Air
Walls, floors, furniture, finishes: these aren’t passive backdrops. They interact with your indoor environment constantly, sometimes releasing compounds, sometimes absorbing them.
Conventional paints, for instance, may release VOCs for weeks after application. Engineered wood products bonded with urea-formaldehyde glues can emit formaldehyde over extended periods, especially in warmer conditions. Vinyl flooring may release phthalates, used as plasticisers to keep the material flexible.
Natural materials behave differently. Clay plaster, for example, releases zero VOCs and helps regulate humidity by absorbing and releasing moisture as conditions change. When we tested three clay paints side by side against a standard emulsion in the same room, the difference in air freshness after 48 hours was striking. Untreated solid wood, natural linoleum, and lime-based finishes contribute to a more balanced indoor atmosphere in similar ways.
Material choices matter beyond aesthetics. What covers your walls and floors affects the air you’re breathing right now.
Signs Your Air Quality Might Need Attention
Indoor air quality problems aren’t always obvious. But certain patterns can suggest your home’s atmosphere deserves investigation.
You might notice lingering chemical or musty odours with no clear source. Condensation forming regularly on windows (indicating high humidity and possibly poor ventilation). Feeling more alert or energetic when outside or in other buildings. Symptoms like headaches, fatigue, or irritated eyes that improve when you leave home. Stuffy or stale-feeling air, especially in bedrooms after sleeping.
None of these signs is definitive on its own, and many have multiple possible causes. But if several ring true, your indoor environment could likely be improved.
Small Steps That Make a Difference
Improving indoor air quality doesn’t require wholesale renovation. Small, consistent actions can meaningfully shift the balance.
Ventilate regularly
Open windows for even a few minutes each day, especially after cooking, showering, or waking up. Cross-ventilation (opening windows on opposite sides of a space) is one of the most effective ways to flush out stale air.
Choose low-emission materials
When redecorating or renovating, look for products certified for low emissions. GREENGUARD certification, for example, indicates a product has been tested and verified for low chemical emissions. Clay and lime-based paints avoid the VOC concerns associated with many conventional coatings.
Mind the humidity
Aim for indoor humidity between 40% and 60%. Too dry, and respiratory passages become irritated; too damp, and mould becomes a risk. Breathable materials like clay plaster help maintain this balance, but ventilation and (where needed) dehumidifiers also play a role.
Be mindful of what you bring in
New furniture, textiles, and materials often have the highest emission rates. Where possible, air new items outside or in a well-ventilated space before bringing them into bedrooms or other occupied areas.
A Note on Certifications
When shopping for materials, certifications can help you make sense of claims. Look for GREENGUARD or GREENGUARD Gold (verified low VOC emissions), EN 16516 (the European standard for emissions testing into indoor air), or the Declare Label (which provides full ingredient transparency and confirms no ‘Red List’ chemicals of concern).
These aren’t the only markers of quality, but they provide third-party verification instead of relying on marketing language alone.
Breathing Easier
Indoor air quality might seem like an invisible concern. Literally. But once you understand the basics, you can begin making choices that improve your daily environment. You don’t need to change everything at once. Even small shifts add up over time: opening windows more often, choosing a natural paint for your next redecoration, being more mindful of what materials you bring into your home.
Your air is shaped by the materials around you. Understanding that connection is the first step toward a healthier home.
Products to Explore
If you’re ready to make a change, consider starting with low-emission paints and finishes. These cover large surface areas and have an immediate impact on indoor air quality. Clay paints, lime washes, and natural oil finishes offer alternatives that support healthier indoor air while bringing their own distinctive character to your walls.
Common Questions
How quickly do VOCs dissipate after painting a room?
It depends on the paint. Conventional paints may off-gas for several weeks, with the strongest emissions in the first 72 hours. Natural clay and lime paints release negligible VOCs from the start, so there’s little to dissipate. Good ventilation during and after painting helps either way.
Can I test my indoor air quality at home?
Basic CO₂ monitors (from around £30–50) give a useful indication of ventilation quality. For VOC testing, more specialised equipment is needed, though affordable handheld sensors are becoming available. If you suspect a specific problem, a professional indoor air assessment may be worthwhile.
Is ‘low VOC’ the same as ‘zero VOC’?
No. ‘Low VOC’ means emissions are below a set threshold, which varies by standard and region. ‘Zero VOC’ means the product contains less than 5g/L of volatile organic compounds. Natural clay and lime paints often test at effectively zero, because there are no synthetic chemicals present to emit.
Do houseplants improve indoor air quality?
Research suggests the effect is modest in real-world conditions. A few plants won’t meaningfully reduce VOC levels in a room. Ventilation and material choices have a far greater impact. That said, plants contribute to wellbeing in other ways.
What’s the single most impactful change I can make?
Ventilation. Opening windows for even five minutes each morning makes a measurable difference to CO₂ levels and humidity. After that, choosing low-emission paints when you next redecorate is the most accessible material change with broad impact.
