Building a home for people with multiple chemical sensitivity

In recent months, several people affected by multiple chemical hypersensitivity have come to our studio.

The fact that our studio specialises in eco-friendly, healthy homes is an added value as architects, as our designs make more sense than ever when it comes to designing a home for people with this type of condition.

What do we take into account when we set out to build a home for people with multiple chemical sensitivity?

Home location

The first thing we will consider is the location. People affected by multiple chemical sensitivity generally prefer to live away from large cities, where toxins and pollution from vehicle exhaust and industry accumulate.

In this regard, our first task is often to support the search for and assessment of plots of land on which to build a home.

The best locations are usually on the outskirts of a small town, which allows access to basic services while living in an environment isolated from chemical threats.

If you have to live in a large city, whether you are moving or not, the best option would be to renovate your home and turn it into a passive house in line with Passivhaus standards.

In a Passivhaus passive house, there is no need to ever open the windows. It is a fully airtight home in which ventilation is provided by a heat-recovery unit with air filters.

This is effective not only for saving energy, as the indoor air is kept at a stable temperature, but it also ensures that indoor air quality is far better than outdoors—something that is impossible in a conventional home.

Toxin-free materials

Nowadays, as with food, many of the materials used to build our homes contain toxic components that are harmful to our health. The most notorious case is asbestos, a highly carcinogenic mineral fibre, but there are many other products that contain carcinogenic components and, because they are present in minimal doses, are considered safe for use in construction.

However, when it comes to our health, it is difficult to trust the minimal doses set by public bodies, which rarely carry out reliable studies, as these cannot be tested on humans and, in most cases, do not take into account the cumulative effect of different toxic components over the years. In addition, it is very difficult to prove a cause-and-effect relationship between cancer or multiple chemical sensitivity after several years or decades living in a home.

Toxins are mainly emitted by plastic products and mineral fibres; varnishes and paints also release volatile organic compounds for several years.

The list is long and complex, and each element of the home would need to be assessed individually and as a whole to determine the amount of toxins present. From rugs, carpets, varnished or lacquered furniture, fabrics, paints, etc., there are many sources of emissions of small particles that go unnoticed by most of our bodies and are the main cause of multiple chemical sensitivity.

In general, the recommendation is to use materials that are as natural as possible. If you are going to build a home, it is important to keep this recommendation in mind for each construction system and interior element, especially wall insulation, flooring, and windows.

It is important to avoid PVC due to its high toxicity during manufacturing and disposal; fibre insulations such as rock wool, which are impregnated with formaldehyde; and plastic paints, which not only prevent the wall from breathing naturally but also tend to emit volatile organic compounds that are absorbed by our lungs.

Appropriate humidity and temperature

It is well known that humidity that is too low or too high is a source of unhealthiness in the home. If the environment is too dry (humidity below 40%), there will be excess dust; if it is too humid (humidity above 70–80%), it becomes a breeding ground for microorganisms and mould.

In this regard, ventilation and the correct use of home heating are particularly important. Some heating systems dry out the air, such as forced-air or convection heating. It is important to ventilate every day and monitor humidity and temperature levels.

In this regard, it should be borne in mind that indoor air quality can, at best, be equal to outdoor air. Not ventilating only leads to a build-up of unhealthy air inside the home.

Appropriate lighting

It is well known that, to stay healthy, we need vitamin D from the sun. It is not only a source of health, but natural light also helps regulate our body’s biorhythms throughout the day.

There is nothing better than waking up peacefully with daylight.

Sunlight also helps improve indoor air quality, as I believe UVA rays are a powerful natural steriliser.

Household chemical products

Finally, the most obvious source of chemicals and toxins in the home is cleaning products.

All you need to do is open the cleaning cupboard and take a look at the labels on each bottle—most carry toxicity warnings. Inhaling, breathing in, or touching these products is a direct source of chemical contamination.

The design of a home for people with multiple chemical sensitivity must also take into account the use of eco-friendly, natural cleaning products.