Insulation materials at a glance

Context : Insulating the greenhouse can significantly reduce energy consumption. An overview of this.

All prices are based on a required heat transfer coefficient (U-value) of 0.24 watts per square meter and Kelvin. Its implementation is  required by the Building Energy Act (GEG) , which, among other things, replaced the Energy Saving Ordinance (EnEV) at the end of 2020.

See also article: Thermal insulation overview

TypeInsulating materialparticularities

Heat protection

Price, net (as of 2022)
Organic Flax Resistance to rot bad ca. 20 €/m 2  (17 cm)
Hemp (mat/plate) Resistant to moisture and rot bad 33 - 53 €/m2 (18 cm / 19 cm)
Wood fiber High heat capacity good 8* - 20 €/m2 (ab 4 cm* / 16 cm)
Wood wool Resistance to vermin, rot and fungal attack good €222/m 2  (34 cm)
Jute Pollutant-free and biodegradable good €21/m 2  (15 cm)
Coconut Fiber Particularly break-resistant, a very good alternative to synthetic insulation materials medium €45/m 2  (18 cm)
Cork Open to diffusion, very pressure-resistant medium - good €117/m 2  (18 cm)
Sheep wool Particularly open to diffusion, cleans room air good €25/m 2  (16 cm)
Reed Resistance to rot and moisture bad €111/m 2  (27 cm)
Seagras High moisture resistance, resistant to mites, mice and other vermin good €20/m 2  (19 cm)
Straw Open to diffusion good

8 - 16* €/m2 (18 cm / ab 4 cm*)

Cellulose Moisture regulating, mold resistant good €8/m 2  (16 cm)
Mineral Expanded Clay Non-flammable, resistant to moisture and frost, good sound insulation good 25,00* €/m2 (ab 4 cm* / 72 cm)
Calciumsilikat Highest fire protection class, alkaline properties prevent mold medium €366/m 2  (24 cm)
Glass wool (matte) Non-flammable, resistant to mold and vermin medium 10 - 25 €/m2 (24 cm / ab 4 cm*)
Mineral foam Dimensionally stable, pressure-resistant, non-flammable good €66/m 2  (20 cm)
Perlite Water-repellent, bug-resistant, will not rot good €40/m 2  (20 cm)
Foam glass Poor soundproofing, no malleability medium €136/m 2  (16 cm)
Rock wool (mat, soft) Non-flammable, resistant to mold and vermin medium 16* - €38/m 2  (14 cm)
Synthetic Extruded polystyrene (XPS) Insensitive to water, tread-resistant, highly flammable good €30/m 2  (14 cm)
Expanded polystyrene (EPS) High moisture resistance good 12 - 19  €/m2 (14 cm / ab 4 cm*)
Polyurethane (PUR) Elastic good €26/m 2  (10 cm)
Polyisocyanurate rigid foam (PIR) Weather-resistant, water-repellent, pressure-resistant good €96/m 2  (19 cm)

Source: IpeG Institute. *= blown-in insulation; Material thickness depends on the cavity, but at least 4 cm.

 

Overview of insulation effect

Insulation material overview

Photo: Research Institute for Thermal Insulation eV

Insulating material

Thermal conductivity

Application

Glass wool

0,030-0,040 W/(m·K)

Roof: insulation between rafters

Ceiling: impact sound insulation

Wall: ETICS, rear-ventilated insulation

Rock wool

0,030-0,040 W/(m·K)

Roof, facade, screed

Foam glass

0,036–0,060 W/(m·K)

Flat roof, facade, interior insulation

Perlite

0,038 – 0,050 W/(m·K)

Expanded perlite: insulation between rafters,
core insulation

Perlite insulation panels: flat roofs,
covering fills

SLS 20

0,035 W/(m·K)

Exterior wall: Core insulation of double-skinned
masonry,
insulation behind clinker brick facades using
the blown-in process

Calcium silicate

0,053–0,07 W/(m·K)

Internal insulation

EPS

0,035-0,040 W/(m·K)

Screed, facade (ETICS), flat roofs

PUR rigid foam

0,025-0,030 W/(m·K)

Flat roof, pitched roof (over-rafter insulation)

XPS 0,030-0,040 W/(m·K) Perimeter insulation, foundation,
facade (ETICS),

Wood fibers

0,040-0,055 W/(m·K)

lightweight constructions,

in connection with fills,

Roof, screed, ETICS

Wood wool

0,090 W/(m·K)

Plaster base, summer heat protection, cladding

Cork

0,045 W/(m·K)

 

Cellulose

0,040 W/(m·K)

Between rafter insulation

Wooden frame construction

Wall/ceiling surfaces

Flax

0,040 W/(m·K)


Under-rafter insulation, not suitable for external insulation

Hemp

0,040-0,045 W/(m·K)

Between rafter insulation,
under rafter insulation

Neptune ball fibres

0,045 W/(m·K)

Blown-in insulation for cavities, roofs,
facades, interior and exterior insulation

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