What Makes a Home ‘Healthy’?

We Spend 90% of Our Time Indoors

It’s a striking figure, and one worth sitting with. Most of us spend the vast majority of our lives inside buildings: our homes, offices, shops, schools. The outdoor world we think of as ‘the environment’ touches us far less than the indoor environments we create.

So the materials in our homes matter more than we tend to assume. The paint on our walls releases compounds into the air we breathe. The finish on our floors is something our bare feet touch each morning. Insulation hidden within our walls determines whether moisture builds up or moves freely through the structure.

What are these materials doing while we’re not paying attention?

Four Qualities of Healthy Home Materials

After years of research into building materials and their effects on indoor environments, we’ve arrived at four qualities that define what we consider a ‘healthy home’ material. None of these on their own is sufficient; it’s the combination that matters.

Low-toxic

A low-toxic material releases minimal or no harmful chemicals into your indoor air. This includes VOCs (volatile organic compounds, the chemicals that create that ‘new paint smell’) and formaldehyde, which can off-gas from certain engineered woods and adhesives for months or even years after installation.

Transparent

You can find out what’s actually in it. The manufacturer discloses ingredients and avoids known hazardous substances, what the building industry calls ‘Red List’ chemicals. If a company won’t tell you what’s in their product, that’s information in itself.

Actively beneficial

Some materials go further than avoiding harm. They contribute something positive to your indoor environment. Natural clay plaster, for instance, can absorb and release moisture, helping regulate humidity in your rooms. Wood fibre insulation does the same within your walls, reducing the conditions where mould thrives. We look for materials that give back, not just ones that stay out of the way.

Verifiable

Claims are backed by evidence, typically through third-party certification. Look for labels like GREENGUARD (which verifies low chemical emissions) or the Declare Label (which confirms ingredient transparency). These certifications exist because ‘healthy’ is an easy claim to make and a harder one to prove.

What We Choose to Exclude

Just as important as what we include is what we leave out. We select products free from formaldehyde, PVC, phthalates, and other chemicals that research has linked to health concerns. These substances appear in more building materials than you might expect. Certain engineered woods. Vinyl flooring. Some paints and adhesives.

We share this because it helps explain our selection, not to alarm anyone. Many homes contain these materials and the people living in them are perfectly well. But when you have a choice (when you’re painting a room, replacing flooring, or choosing insulation) why not choose materials that work with your body?

We follow the building industry’s ‘Red List’ as our guide, developed by the International Living Future Institute. It represents the current scientific consensus on which substances we’d be better off without in our homes.

The Unexpected Benefit: Individuality

Something we noticed early on: choosing healthier, natural materials often means choosing materials with character.

A clay-plastered wall has subtle texture and depth that shifts with the light. Solid wood flooring carries grain patterns that are never quite repeated. Hand-finished surfaces bear the gentle marks of their making. The knots and colour variations are what give each piece its own identity.

Mass-produced synthetic materials are designed for uniformity. Every sheet of vinyl flooring looks the same. Every can of synthetic paint produces an identical finish. There’s a place for that, certainly. But it also means your home looks like every other home that used the same products.

Natural materials tell a different story. The oak in your floorboards grew for decades in a specific forest. The clay on your walls came from a particular quarry. Over time, these materials develop a patina, a gentle ageing that deepens their character. Your home becomes more distinctively yours with each passing year.

Where Science Meets Feeling

We can measure VOC emissions. We can certify the absence of harmful chemicals. We can test how materials regulate moisture. These are the scientific foundations of healthy materials, and they matter.

But how natural materials make us feel is harder to quantify. The warmth of wood underfoot on a cold morning. The softness of natural plaster compared to synthetic alternatives. The way light plays across surfaces that have genuine texture, real depth, visible grain.

Research in biophilic design suggests that humans respond positively to natural materials at a fundamental level, that our nervous systems recognise and relax in their presence. Whether you call this science or intuition, most people feel it. A room with natural materials feels different. Walk into one and you’ll know.

You Don’t Need to Change Everything

If you’re reading this and feeling overwhelmed, looking around at walls and floors and wondering where to even begin, take a breath. A healthy home isn’t an all-or-nothing proposition.

Start with the room you spend the most time in. For many of us, that’s the bedroom, where we spend a third of our lives breathing the same air for eight hours at a stretch. When you next need to repaint, choose a low-VOC natural paint. When flooring needs replacing, consider solid wood or natural linoleum.

Each small choice adds up. Over years, as you make decisions about maintenance and improvement anyway, you can gradually shift your home toward healthier materials. No deadline. No finish line. Just the gentle accumulation of better choices.

Where to Start

If you’re curious about your home’s breathability, begin by noticing. Do you see condensation on windows regularly? Does any room feel persistently damp or stuffy? When you next redecorate, consider choosing a breathable finish: clay paint or limewash instead of vinyl-based products. The change may be invisible, but its effects on moisture and air quality are real.

Products to Explore

Clay paints and plasters, lime washes, and mineral silicate paints all offer breathable alternatives to conventional finishes. For larger projects, natural insulation materials like wood fibre, hemp, and sheep’s wool combine thermal performance with excellent vapour permeability, allowing your walls to breathe from the inside out.

Common Questions

What’s the difference between ‘breathable’ and ‘ventilated’?

Ventilation moves air through openings (windows, vents, mechanical systems). Breathability is about moisture vapour passing through materials at a molecular level. Your home needs both: ventilation for fresh air exchange, and breathable materials to buffer humidity between ventilation events.

Will breathable walls let rain through?

No. Breathable materials allow water vapour to migrate through but resist liquid water. A lime-rendered wall, for instance, sheds rain on the outside while allowing indoor moisture to escape. The distinction between vapour and liquid is key.

Can I make my walls more breathable without replastering?

Yes. Switching from vinyl-based paint to clay paint or limewash at your next redecoration improves breathability without removing existing plaster (provided the underlying surface is already porous). It’s one of the most accessible changes you can make.

Do breathable walls work with underfloor heating?

Breathability is mainly about moisture movement through wall and ceiling surfaces. Underfloor heating doesn’t conflict with breathable walls. In fact, the warmth from underfloor heating can help drive moisture outward through breathable walls, improving the system’s performance.
How do I know if my older home was originally breathable?
If your home was built before roughly 1920 and has solid walls (stone, brick, or cob), it was almost certainly designed to breathe. Lime mortar, lime plaster, and limewash were standard. If those original finishes have been replaced with cement render or vinyl paint, restoring breathability is well worth considering.