As a buying agent, I went looking for a home in Hilversum together with a lovely expat couple. One of the children quickly got short of breath. They had quite a list of requirements and there was time pressure behind it. They had a rental home for a set number of months. I was at a birthday party and the brother of a friend of my mum's told me he wanted to sell the house next door to him. But he also told me something very interesting. He had renovated that old building entirely with natural building and insulation materials. He felt that was important: both for a pleasant indoor climate and for the planet. We went to view it together and, strangely enough, we all immediately understood what he meant. The house felt pleasant, there was a good energy and the deal was sealed. This was about 5 years ago. He had renovated it another 5 years before that. We weren't yet so concerned with our energy label and making our homes more sustainable. Natural building materials weren't top of mind yet either.
Contents
- Using natural materials
- Benefits of natural materials
- Which natural materials should you choose?
- Finishing your home with natural materials
- Green roof
- Working with natural materials
Using natural materials
Natural insulation materials, such as flax, hemp and recycled cotton, not only offer excellent insulating properties, but also contribute to a more sustainable lifestyle. By choosing materials that are renewable, recyclable and biodegradable, you significantly reduce your ecological footprint.
Benefits of natural materials
At first, natural insulation materials seem more expensive. But they have so many benefits
1. Sustainable production
One of the biggest strengths of natural insulation materials is their sustainable production. These materials are often obtained from renewable sources and have a positive CO2 balance. Traditional insulation materials, such as glass wool and EPS (polystyrene), draw on non-renewable sources. Extracting these materials contributes to the depletion of natural resources and increases dependence on fossil fuels. Natural insulation materials such as hemp, flax and sheep's wool, on the other hand, draw their strength from renewable sources. This means they're less dependent on finite fossil raw materials, resulting in a lower ecological footprint. While some are all for using sheep's wool, Milieucentraal advises against using sheep's wool:
- 20 times higher greenhouse gas emissions compared with rock wool or glass wool.
- 4 times higher emissions than rigid plastic foam insulation with the same Rd value.
- More than 20 years needed to offset the environmental impact through CO2 savings.
- Sheep manure causes more nitrogen in the soil, which is harmful to biodiversity.
- Use of pesticides in sheep's fleece against vermin
2. Healthy indoor climate
Natural insulation materials regulate not only temperature, but also moisture. Natural building materials, such as wood and bamboo, contribute to a healthy, breathable and stable indoor climate. These materials promote ventilation and keep homes cool in summer and warm in winter. This results in better health and comfort for the occupants. Many traditional insulation materials contain chemicals and toxic substances. Natural materials avoid these problems, which improves air quality in the home and reduces allergies.
3. Easy to work with
Unlike some synthetic materials, natural insulation materials are often easy to work with. Recycled cotton and paper flakes (cellulose), for example, are easy to handle and install, which simplifies the insulation process.
Which natural materials should you choose?
You're getting ready for the future. But you want to choose natural materials that are just as effective as traditional materials. You want a comfortable home with a healthy indoor climate and good protection against heat, noise and moisture. You also want to save on your energy bill. But which materials should you choose to make your home more sustainable? What should you look out for?
Sheep's wool:
- Advantages:
- Very good moisture- and vapour-regulating properties.
- Can absorb up to 30% of its weight in water.
- Neutralises harmful gases and contributes to a healthier indoor climate.
- Easy to install without chemical agents.
- Disadvantages:
- Fairly high purchase price
- 20 times higher greenhouse gas emissions compared with rock wool or glass wool.
- 4 times higher emissions than rigid plastic foam insulation with the same Rd value.
- More than 20 years needed to offset the environmental impact through CO2 savings.
- Sheep manure causes more nitrogen in the soil, which is harmful to biodiversity.
- Use of pesticides in sheep's fleece against vermin
Flax insulation:
- Advantages:
- Very high natural moisture-regulating and mould-resistant capacity.
- Environmentally friendly production with recyclable and recoverable material.
- Positive CO2 balance.
- Disadvantages:
- Fairly high purchase price.
- Harder to work with because it's stiff.
Hemp:
- Advantages:
- Low-dust installation.
- Optimal moisture regulation and good sound-insulating properties.
- Resistant to insects and mould.
- Disadvantages:
- Fairly high purchase price.
- Vulnerable to moisture.
Wood fibre:
- Advantages:
- Good sound-insulating properties.
- Suitable for various insulation applications.
- Vapour-permeable with a good moisture balance.
- Disadvantages:
- Fairly high purchase price.
Recycled cotton:
- Advantages:
- Recycled and sustainable.
- Excellent thermal, acoustic and moisture-regulating properties.
- Easy to handle and work with.
- Disadvantages:
- Less suitable for damp locations.
Paper flakes (cellulose):
- Advantages:
- Recycled and environmentally friendly.
- Easy to use in renovations.
- Relatively cheap.
- Disadvantages:
- Not suitable for damp locations.
These materials fit perfectly into the concept of a circular economy. They're biodegradable and can often be recycled after use, which reduces the mountain of waste and extends the life cycle of the material.
Finishing your home with natural materials
Last year I bought a house on behalf of a mother with young children. She wanted to renovate the house completely, but the children had a lot of allergies. For her it was important that the home was finished naturally, so they would suffer less from their allergies. In her new-build home she had already used a great painter who had recommended natural paints to her. She had been so pleased with this that she definitely wanted the same in her new house.
So what's possible?
- Clay plaster: Natural credentials: Clay plaster is a natural material made of sand, clay and silt. Properties: It has excellent moisture-regulating properties and can provide a warm, breathable finish. Applications: Clay plaster is often used in both historic restorations and modern designs.
- Lime plaster: Natural credentials: Lime plaster is made from slaked lime and fine aggregates such as marble powder. Properties: It has disinfecting properties, is mould-resistant and is highly breathable. Applications: Lime plaster is often used in old buildings, but it's also suitable for modern applications.
- Gypsum clay: Natural credentials: Gypsum clay consists of gypsum, clay and aggregates such as straw. Properties: It provides thermal insulation and regulates moisture naturally. Applications: Gypsum clay is often used for both walls and ceilings.
- Tadelakt: Natural credentials: Tadelakt is a waterproof lime-based plaster. Properties: It has a glossy finish and is moisture-resistant, making it suitable for bathrooms and kitchens. Applications: Traditionally used in Morocco, tadelakt is becoming increasingly popular in modern designs.
- Clay paint: Natural credentials: Clay paint is made from natural clay, chalk, marble powder and natural pigments. Properties: It's breathable, absorbs odours and regulates moisture. Applications: Ideal for both indoor and outdoor use, depending on the specific brand.
- Mineral paint: Natural credentials: Mineral paint is made from mineral pigments and lime. Properties: It's highly breathable and resistant to mould and bacteria. Applications: Suitable for indoor and outdoor use, and it can be applied to various surfaces.
- Casein paint: Natural credentials: Casein paint is made from casein, a milk protein, mixed with natural pigments. Properties: It has a soft, matt finish and is suitable for various substrates. Applications: Often used for historic restorations, but also suitable for modern interiors.
Before you use these natural materials, it's wise to get advice from a professional. In general they're more delicate, and not every finish is suitable for every room.
Green roof
At sailing camp when I was 14, I met Daniel Schoenmaker. As it happened, we went to the same secondary school. Back then we were mainly busy staying up as late as possible and sailing. We kept bumping into each other by chance. Like the time I was cycling along the Burgemeester Reigerstraat after a viewing. He was walking with some people I knew. He had gone to work for Topgroen. A company that creates green roofs. A green roof is a ‘beautiful’ form of sustainable insulation.
A green roof, also known as a sedum roof or a vegetation roof, offers insulating properties as well as aesthetic benefits. The insulation value of a green roof can improve a building's thermal performance in various ways:
- Thermal insulation: Summer: A green roof can reduce heat transfer into the building, keeping it cooler in summer. Winter: In winter the green roof acts as an extra layer of insulation, reducing heat loss through the roof.
- Heat absorption and release: A green roof can absorb part of the solar radiation and then release it again, reducing temperature fluctuations inside the building.
- Sound insulation: Green roofs can also have sound-insulating properties, reducing the transmission of noise from outside to inside.
- Longer life for the roof covering: The roof covering under the green roof is protected from the weather, which can extend its lifespan.
- Air quality: Plants on the green roof can contribute to improved air quality by absorbing carbon dioxide and releasing oxygen
Do make sure your roof is suitable for a green roof. It can get pretty heavy. We once had a house for sale where everything had always been fine, until it started snowing. Then the green roof became so heavy that it started leaking.
Working with natural materials
At the Christmas drinks I was talking to potential clients about their new house. They said they were still in two minds about natural materials. They said it's a bit more expensive, of course. But it also seems really pleasant to us. We're now weighing up whether it's feasible for us. So the house needs to sell well. The materials are somewhat more expensive to buy, but at the same time you can get subsidies for them and they're better for your health. Natural materials have health benefits and environmental benefits. Do you want to make your home more sustainable? Get advice.
Planning a renovation and need an extra mortgage for it, or will you get an extra interest discount afterwards? Let us value your home.
