What are alternatives to polystyrene

Thermal insulation with polystyrene: experts advise against it

Polystyrene (Styrofoam) is by far the most widely used insulation material. It's cheap and easy to work with. But experts warn of problems: the insulation material could soon be declared hazardous waste. Building owners recommend alternatives.

"Who today turnkey builds And if you want a plastered facade, you almost exclusively get facades with a thermal insulation composite system made of polystyrene ", reports Thomas Penningh, President of the Association of Private Builders (VPB). The construction companies appreciate the material: It is easy to handle and can sometimes be in the rain.

Disadvantages of polystyrene

In addition, polystyrene is comparatively cheap. "Most builders of course look at the price. They are usually not given any alternatives," says Penningh. That annoys him. Because the cheap one Thermal insulation is not unproblematic.

Because polystyrene catches fire quickly, the insulation material is often provided with the flame retardant hexabromocyclododecane (HBCD). "HBCD is an environmental toxin that accumulates heavily in organisms, is suspected of being harmful to reproduction and is also very long-lived," explains the Federal Environment Agency (UBA). A worldwide production and application ban has been in effect since 2013. So far, an exception has only been made for use in insulation boards. But that will change in the medium term.

"If polystyrene with HBCD as a fire retardant is actually treated in accordance with the regulations for hazardous waste in the near future, then building owners will have a problem," warns VPB President Penningh. "Hundreds of thousands of builders would then have hazardous waste on their hands with the stroke of a pen facade."

The insulation material is also criticized because biocides are often added to it. This is to prevent algae and mold growth on the insulated house walls.

Alternatives to polystyrene

Experts therefore advise switching to other insulation materials. "When it comes to thermal insulation, we recommend using materials that either do not require any flame retardants that are harmful to the environment or health or require no flame retardants at all, such as mineral wool," says Jochen Flasbarth, President of the Federal Environment Agency.

Client advocate Pennigh advises the Facade insulation to mineral and wood fiber boards. The materials are on the market, but not only have higher costs but also disadvantages: mineral and wood fiber boards do not achieve the same insulation values ​​with the same thickness as polystyrene. They have to be correspondingly thicker, which in turn requires different cuts and attachments.

Insulated stones as an alternative to polystyrene

Another alternative can be insulated stones. Such stones are available, for example, as bricks or made of aerated and lightweight concrete, explains the German Society for Masonry and Housing Construction. The insulation is partly located in the holes within the stones; in clay bricks, for example, thermal insulation made of perlite or mineral wool is integrated.

However, the insulated stones cannot be cut to size at will. That is why there are special stones for corners and recesses. Their use must be carefully planned. All of this drives up the cost. Many companies don't even offer it. "And as long as the builders don't ask for alternatives, that won't change either," said the VPB President.

Natural insulation for the roof

If you are planning your house now, you should get advice from independent experts about alternatives, advises the VPB. "At least for the insulation of the roof, ecological building materials are well suited," says Penningh. "These include flax, hemp, jute, cellulose, wood fiber or even sheep's wool."

However, one also has to look carefully here. Often, insulation materials such as wool are also provided with flame retardants. "They reduce the ecological value of the product again." Penningh recommends looking for quality seals such as "natureplus" or the "Blue Angel".