Hemp as an insulation material

Hemp is one of the oldest crop plants; it grows very quickly and makes hardly any demands on soil quality, and neither fertilisers nor pesticides are needed. This makes hemp a particularly ecological insulation material to produce. Hemp can also be grown here in Germany, so there are no long transport routes.

als Nächstes: Jute

Thermal conductivity of hemp:
good | 0.04–0.05W/(Km³)

Heat storage capacity:
good/medium

Vapour diffusion resistance:
1–2

Insulation thickness:
16 cm

Primary energy demand:
30kWh/m³

Fire safety class:
B2

Sound insulation:
good

Bulk density/weight:
35 kg/m³

Costs:
€–€€

Indoor climate:
naturally antibacterial and fungicidal, that is, resistant to mould. It is also insect-proof.

Sheep's wool as an insulation material

Sheep's wool can be produced anywhere sheep are kept. It can be sourced regionally, but some of it also travels long transport routes from New Zealand. Recycled waste wool is used as well. One drawback is that without the addition of boron salts it is susceptible to insect attack. The boron salts, however, make it somewhat harder to dispose of.

als Nächstes: Polystyrole

Thermal conductivity of sheep's wool:
very good | 0.035–0.045 W/(Km³)

Heat storage capacity:
medium

Vapour diffusion resistance:
1–2

Insulation thickness:
16–18 cm

Primary energy demand:
low | 40–80 kWh/m³

Fire safety class:
B2 (but naturally flame-retardant)

Sound insulation:
good

Bulk density/weight:
20 kg/m³

Costs:
€€€

Indoor climate:
purifying effect on the
indoor air, good moisture regulation,
offers protection against mould and pest damage

Cork as an insulation material

Cork is obtained from the outer bark of the cork oak, which can be stripped from the age of 20 onwards about every 10 years without the tree coming to any harm. The first stripping is well suited to the production of insulation materials, as its high resin content makes it less suitable for producing wine corks. Recycled corks are, however, also used in insulation production. The cork is first ground into a fine granulate, which is then expanded using hot steam. This produces cork grit, which can be used as loose-fill insulation. To make boards, the granulate is expanded in special moulds. This releases natural resins that act as a binder. One disadvantage is that although cork is a renewable raw material, it is a particularly valuable and slow-growing one. In addition, the cork oak is not native here, which means longer transport routes. The production process is relatively energy-intensive because of the high temperatures required. On top of that, it can develop a slight odour of its own, which not everyone likes. Cork boards can also become very heavy, which is something you tend to want to avoid in tiny house construction.

als Nächstes: Schilf

Thermal conductivity of cork:
good | 0.04–0.06 W/(Km³)

Heat storage capacity:
good

Vapour diffusion resistance:
5–10

Insulation thickness:
18 cm

Primary energy demand:
relatively high | 65–450 kWh/m³

Fire safety class:
B2

Sound insulation:
good

Bulk density/weight:
80–500 kg/m³

Costs:
€€

Indoor climate:
Cork is hard-wearing, insensitive to moisture and resistant to decay, rot and pests, it is breathable and can absorb and release moisture well. It also offers protection against rodents. Cork is chemically neutral by nature and no further substances need to be added.

Jute as an insulation material

Jute is a plant grown mainly in India and Bangladesh. Although the plant is not grown in Europe, jute insulation has a good environmental balance, because used cocoa or coffee sacks are used for the insulation material. A good example of upcycling. To produce the insulation mats, small amounts of other natural or synthetic fibres are added for stability. If only natural fibres have been added, it is fully biodegradable and particularly easy to dispose of. There are now also combined insulation materials made from jute and hemp that bring together the advantages of both products.

als Nächstes: Holzfaser

Thermal conductivity of jute:
very good | 0.038–0.045 W/(Km³)

Heat storage capacity:
very good/high

Vapour diffusion resistance:
1–2

Insulation thickness:
16 cm

Primary energy demand:
about 50–90 kWh/m³

Fire safety class:
B2

Sound insulation:
good

Bulk density/weight:
34–40 kg/m³

Costs:
€–€€

Indoor climate:
good moisture regulation, offers protection against mould and pest damage.

Polystyrene as an insulation material

These insulation materials are very widespread and are a typical floor insulation in tiny houses. Their production is based on finite fossil fuels such as natural gas, crude oil and hard coal. Toxic substances are released during production and in the event of a fire. Disposal usually takes place in landfill or through incineration that harms the climate, as recycling is very expensive.

als Nächstes: Mineralwolle

Thermal conductivity of polystyrene:
very good | 0.032–0.045 W/(Km³)

Heat storage capacity:
medium

Vapour diffusion resistance:
20–100 (EPS)
80–200 (XPS)

Insulation thickness:
14 cm

Primary energy demand:
low | 200–760 kWh/m³ (EPS)
450–1000 kWh/m³ (XPS)

Fire safety class:
B1/B2

Sound insulation:
poor

Bulk density/weight:
15–30 kg/m³ (EPS)
25–50 kg/m³ (XPS)

Costs:
€–€€

Indoor climate:
resistant to rot
and insects, very durable
as far as moisture, decay
and ageing are concerned, but
not UV-resistant.

Reed as an insulation material

Reed is a native marsh plant whose stalks have good qualities as an insulation material. Several reed stalks aligned parallel to one another are pressed into boards and tied together with wire. No further additives are needed for binding or anything similar, so the result is a 100 % natural product. Reed is resistant to moisture, rot and mould. It is very easy to recycle and, since no additives have been used, it is fully compostable. Production is very environmentally friendly and requires little energy. It has a high heat capacity and thus protects against summer heat, and it also has sound-insulating properties. It is comparatively inexpensive as well.
One disadvantage, especially when building tiny houses, is its high weight.

als Nächstes: Flachs

Thermal conductivity of reed:
good | 0.04–0.055 W/(Km³)

Heat storage capacity:
high

Vapour diffusion resistance:
2

Insulation thickness:
18 cm

Primary energy demand:
low

Fire safety class:
B2

Sound insulation:
good

Bulk density/weight:
190 kg/m³

Costs:

Indoor climate:
Reed is resistant to moisture, rot and mould. It is very easy to recycle and, since no additives have been used, it is fully compostable. Production is very environmentally friendly.

Wood fibre as an insulation material

Wood is one of the oldest industrially produced natural insulation materials. Insulation boards are made largely from wood residues from industry and partly from trees felled during thinning that are too thin for structural use.

als Nächstes: Kokosfaser

Thermal conductivity of wood fibre:
good | 0.04–0.045 W/(Km³)

Heat storage capacity:
very good/high

Vapour diffusion resistance:
3–5

Insulation thickness:
18 cm

Primary energy demand:
about 600–785 kWh/m³

Fire safety class:
B2

Sound insulation:
very good

Bulk density/weight:
265–560 kg/m³

Costs:
€€–€€€

Indoor climate:
good moisture regulation

Mineral wool as an insulation material

als Nächstes: Zellulose

Thermal conductivity of mineral wool:
very good | 0.032–0.045 W/(Km³)

Heat storage capacity:
low

Vapour diffusion resistance:1

Insulation thickness:14 cm

Primary energy demand:150–700 kWh/m³

Fire safety class:
A2 (or A1 for rock wool)

Sound insulation:
good

Bulk density/weight:
22–50 kg/m³

Costs:
€

Indoor climate:
resistant to mould,
rot and insects

Flax as an insulation material

Flax, too, is a plant grown in Germany that has been used for centuries to produce clothing. Its seeds are used to make versatile linseed oil. The plant is very robust and no pesticides are needed to grow it. As with hemp and jute, the fibres from the stalk of the plant are processed into insulation material. The short fibres from the stalk are often a by-product of linen production. Needle rollers felt the fibres into fleeces, which are then bonded into boards with starch. In some cases synthetic woven fibres are incorporated for support. As with hemp or jute, salts (e.g. boron salt) are added as fire retardants. Flax is only partly suitable for protection against overheating. It also cannot be used for external façade insulation. Another disadvantage is that flax insulation materials are hard to obtain.

als Nächstes: Hanf

Thermal conductivity of flax:
very good | 0.04–0.045 W/(Km³)

Heat storage capacity:
medium

Vapour diffusion resistance:
1–2

Insulation thickness:
15 cm

Primary energy demand:
low | 70–80 kWh/m³

Fire safety class:
B2 (but naturally flame-retardant)

Sound insulation:
good

Bulk density/weight:
20 kg/m³

Costs:
€€€

Indoor climate:
largely resistant to rot, mould and insect attack, very good moisture-regulating properties

Coconut fibre as an insulation material

Coconut fibres are obtained from the husk of coconuts. The husks are exposed to a rotting process in large tanks, which leaves the resistant fibres behind. These are then washed, dried and, usually without further additives, processed into fleeces by mechanical needling. Boron salts are sometimes used to improve fire protection.

als Nächstes: Schafwolle

Thermal conductivity of coconut fibre:
good | 0.04–0.05 W/(Km³)

Heat storage capacity:

Vapour diffusion resistance:
1

Insulation thickness:
18 cm

Primary energy demand:

Fire safety class:
B2

Sound insulation:
good

Bulk density/weight:
70–125 kg/m³

Costs:
€€–€€€

Indoor climate:
purifying effect on the
indoor air, good moisture regulation,
offers protection against mould and pest damage

Cellulose as an insulation material

The cellulose for insulation materials is obtained from shredded waste paper, for example from unread newspapers. Mechanical shredding changes the structure of the paper and forms cellulose flakes. These flakes can be used directly as blown-in insulation. To produce insulation boards, the fibres are pressed into boards using steam. The steam activates the binders already present in the cellulose, so no additional adhesives are needed. For fire protection, however, aluminium sulphate and boron salts are added, and additional fibres such as jute yarn can be worked in for stability. Cellulose has good insulating properties and also offers good protection against summer heat. Cellulose boards are very easy to dispose of. Cellulose is also comparatively inexpensive for an ecological insulation material. As blown-in insulation, cellulose plays no role in tiny house construction, because there is a risk that movement of the house will cause the flakes to settle and create voids in the insulation.

als Nächstes: Kork

Thermal conductivity of cellulose:
good | 0.04–0.045 W/(Km³)

Heat storage capacity:

Vapour diffusion resistance:
1–2

Insulation thickness:
16 cm

Primary energy demand:
low | 55–80 kWh/m³

Fire safety class:
B1

Sound insulation:
very good

Bulk density/weight:
30–70 kg/m³

Costs:
€–€€

Indoor climate:
resistant to mould and insects, durable, vapour-permeable, has a moisture-regulating effect.

Price list

Campervan consulting	€90/h
Tiny house consulting	€90/h
Initial consultation	30 min, donation-based
Hands-on work, per hour	on request
Travel to and from site	by arrangement

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Tiny House PRO | Tiny House knowledge

Insulation

Keeping cold and heat outside

Since almost every wall in a tiny house is also an external wall, effective insulation is particularly important. With inadequate insulation, a great deal of heat can be lost when outside temperatures are low, while in summer the house would heat up uncomfortably.

With insulation, it is not only the amount and type of insulation material that affects comfort in a tiny house, but also proper installation. Good insulation ensures a pleasant temperature in the house and at the same time has a positive influence on the indoor climate.

Not least, well-executed insulation also contributes to climate protection: it reduces energy consumption and therefore both CO2 emissions and heating costs.

Good insulation ensures a pleasant living climate and keeps energy consumption low.

Topics:

Insulation materials | Explanations of terms

It’s the material that matters

Effective insulation is indispensable for protecting the tiny house from cold in winter and heat in summer, reducing energy consumption and creating a pleasant indoor climate. But which insulation materials are best suited to tiny houses, and what properties do they have? Here I present the most important insulation materials and give an overview of their advantages and disadvantages. Further down you will find explanations of the terms used.

Hemp

Sheep's wool

Cork

Jute

Polystyrene

Reed

Wood fibre

Mineral wool

Flax

Coconut fibres

Cellulose

Terms & Definitions

Thermal conductivity:

(also called the U-value) is a material's ability to transport heat. It is given in W/(mK) (watts per metre and kelvin). The lower the value, the better the insulation. Values below 0.05W/(mK) indicate good thermal insulation. When it comes to thermal conductivity, it is above all the conventional insulation materials that score well. The thickness of the insulation depends essentially on a material's thermal conductivity.

Which insulation material ultimately suits your wall build-up depends on weight, wall thickness and budget. In the Tiny House consulting I go through this in detail for your project.

Heat storage capacity:

can be regarded as a measure of thermal protection in summer. It refers to the period between the highest temperature occurring on the outside of a material and that temperature being reached on the inside. Because of their generally higher bulk density, ecological insulation materials offer much better protection against overheating in summer. The more heat a material can store, the more slowly it responds to heating and cooling. In this way the material can have a balancing effect on the indoor climate. Wood and jute insulation materials perform best here.

Vapour diffusion resistance:

is the ability to exchange moisture; it is measured in μ (mu). The lower the value, the more easily water vapour can pass through the insulation material. The vapour diffusion resistance of the individual materials in an external wall should decrease from the inside outwards, in order to avoid condensation forming within the wall. Natural insulation materials in particular are also able to absorb moisture without losing their insulating effect. In the worst case, insulation materials with a high vapour diffusion resistance reduce moisture regulation at the walls. That leads to condensation and, as a result, to mould growth.

Indoor climate:

Improper thermal insulation can have a negative effect on the indoor climate. Insulation materials with a high vapour diffusion resistance can reduce moisture regulation at the walls, which can lead to condensation and, as a result, to mould growth. The heat storage capacity of a material mentioned earlier can also contribute to a pleasant indoor climate, especially in summer.

Fire protection:

Insulation materials are also divided into fire classes. Almost all ecological insulation materials fall into class B2, which stands for normally flammable. Conventional insulation materials achieve a higher fire class here, but often develop toxic fumes if they do catch fire. Natural insulation materials usually have soda added as a flame retardant, a salt that is also approved in the food industry.

Sound insulation:

Unpleasant background noise such as traffic, passing trains or the neighbour's dreadful taste in music can also play an important role in choosing an insulation material with regard to its sound-insulating properties.

Insulation thickness:

The insulation also affects the thickness of the wall. Whether you want or have to comply with the German Energy Saving Ordinance also comes into play here. Depending on the material and wall build-up, you end up with a wall thickness of 20–40 cm.

Weight:

The bulk density indicates how heavy an insulation material is. With mobile versions in particular, this factor should not be underestimated. This is also where the disadvantage of some ecological insulation materials lies, as they are simply too heavy for tiny houses.

Costs:

When choosing the insulation material, it is worth bearing in mind financially that good insulation has a positive effect on heating costs.

Not only thermal conductivity is important, but also heat storage capacity. If an insulation material has good values for both, it offers protection against cold as well as against overheating in summer.

Hemp as an insulation material

Sheep's wool as an insulation material

Cork as an insulation material

Jute as an insulation material

Polystyrene as an insulation material

Reed as an insulation material

Wood fibre as an insulation material

Mineral wool as an insulation material

Flax as an insulation material

Coconut fibre as an insulation material

Cellulose as an insulation material

Price list

Tiny House PRO | Tiny House knowledge

Insulation

Keeping cold and heat outside

Topics:

It’s the material that matters

Hemp

Sheep's wool

Cork

Jute

Polystyrene

Reed

Wood fibre

Mineral wool

Flax

Coconut fibres

Cellulose

Terms & Definitions

Thermal conductivity:

Heat storage capacity:

Vapour diffusion resistance:

Indoor climate:

Fire protection:

Sound insulation:

Insulation thickness:

Weight:

Costs:

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