ᐅ Healthy Building – What Is Important?

Gerddieter schrieb:

But what about all the sources of volatile substances, adhesives, PU foam, and so on...

What can I do, and what have you done, to live as healthily as possible here?

I can share what we did: since the largest surfaces are the walls and ceilings, we had them painted with silicate paint (preferably on lime plaster) instead of dispersion paint (dispersion paint is basically like a sprayed-on plastic film with color particles and soluble biocides). The floors are covered with tiles and nailed (not glued) solid wood planks oiled. The furniture is almost exclusively made of solid wood. Stair gates are coated with water-based varnish according to EN71 (standard for children’s toys). Oh yes, we needed adhesive for the rubber flooring in the basement, but we also used one based on rubber. You remove volatile substances from indoor air through good, constant ventilation. For this, a controlled mechanical ventilation system is invaluable. The walls are all made of limestone; with timber frame construction, I would have real concerns about the foils, adhesives, and glues most manufacturers use. Expanded polystyrene (EPS) as external insulation doesn’t bother me inside! However, I would pay attention to the exterior paint for biocides, as these are gradually washed out and eventually end up in your soil and garden beds, where children play with the ground and substances reach the groundwater, etc.

Our windows are made of plastic, and of course, construction foam plus compression tape was needed for their installation—there was simply no alternative. However, their surface area isn’t that large. As I said, for Pareto, meaning 80% or more of the maximum achievable result, in my opinion, it is enough to focus on ceilings, walls, floors, and good ventilation.

What does healthy building mean? Is it just about your personal health, or do you also want to consider the global CO2 footprint?
If so, heavy construction methods are off the table; concrete is one of the materials with the highest CO2 emissions. The production of cement is so carbon-intensive that it accounts for up to eight percent of the global annual carbon dioxide emissions.
However, you don’t need to worry as much about emissions from your private living space if you build with concrete.

We specifically looked for a home builder who shared our mindset and paid close attention to ecology and the CO2 footprint.

Be clear about what matters most to you: is it healthy living for yourself alone, or are you also thinking globally? How much money are you willing to spend on this? Highly ecological choices are usually more expensive. What is it worth to you? I find it completely understandable when people say: I do want to be environmentally friendly, but it still has to be affordable for me.
For example, we seriously considered clay plaster but ultimately just applied paint to our Fermacell walls.

So, it’s important to clarify your goal beforehand: how can you achieve it, what is it worth to you, and where do you draw the line?

I must say this is a very interesting topic and highly versatile in its interpretation.

I agree with many points made and would like to add an additional perspective.

A healthy indoor climate results from the exchange of "stale" or "used" air with fresh air.

For me, the very first step is to consider building with vapor-permeable (diffusion-open) materials.

This way, a mechanical ventilation system is not necessary for air exchange, and ideally not even an open window, if the concept is well designed.

Vapor-permeable building materials are in most cases also ecological and healthy, such as wood, clay, lime, cork, and so on.

Many suppliers advertise vapor-permeable membranes, but I am not a fan of those.

Is this the “breathing house” again?

Seppl's Häusle schrieb:

Healthy indoor air quality is achieved by exchanging "stale" or "used" air with fresh air.

That basically means either a) opening windows wide or b) using a mechanical ventilation system with heat recovery.

Seppl's Häusle schrieb:

Therefore, for me, the very first step is considering building with vapor-permeable materials.

In modern houses, virtually no moisture passes through the outer shell. That’s why the blower door test exists, to ensure the building is airtight—regardless of the construction method.

Seppl's Häusle schrieb:

With this, no ventilation system is needed to exchange the air, and you technically don’t even need to open a window if the concept is well designed.

That concept dates back to the 1920s, when windows were built and installed in a way that made them drafty. And indeed, you didn’t have to open windows anymore.

Seppl's Häusle schrieb:

Vapor-permeable building materials are in most cases both ecological and healthy, such as wood, clay, lime, cork, etc.

Too bad you can’t build entire houses with them alone. You still need walls made of masonry or timber frame construction (with the appropriate layers).

Seppl's Häusle schrieb:

A healthy indoor climate is created by exchanging "stale" or "used" air for fresh air.
Therefore, for me, the very first consideration is shifting towards building with vapor-permeable materials.

Vapor-permeable building materials ≠ airtight house

Every modern house is built to be largely airtight. Those who want fresh air must therefore ventilate manually or have a mechanical ventilation system with heat recovery.