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What is better: internal wall cassettes or sandwich panels?


Comparing the main characteristics of internal wall cassettes (IWC) with mineral wool and PIR sandwich panels.

Sometimes, in order to reduce the cost of a project, commercial real estate customers consider several options for wall construction, including those with internal wall cassettes or sandwich panels. At the same time, customers mistakenly believe that the IWC option will be the cheapest.


The internal wall cassette is a profiled steel structure made of galvanized sheet used as a load-bearing wall structure. Unlike prefabricated sandwich panels, IWC is not a ready-made wall structure, but requires further insulation, sealing and installation of external cladding. The advantages of internal wall cassettes include the low price of the product and the possibility to choose different cladding materials for the facade. And the disadvantages are high labor intensity of work, low energy efficiency and durability.


If we compare the total cost of a wall structure including installation based on sandwich panels and IWC with insulation and cladding, then the most attractive solution will be the sandwich panels with polyisocyanurate foam core (see table below). At the same time, mineral wool sandwich panel costs 14% more than structure with IWC, but it’s 15% more energy efficient. The higher energy-saving properties of the sandwich panels allows the building owner to recoup the price difference of wall structures already in the first 2-3 years of operation and save significantly in the future.


<tr”>Total cost of construction including installation, €/m252.359,748.6


internal wall cassettes

IWC 100 mm

sandwich panels

Sandwich panels Ruukki nSPB 100W

sandwich panels

Sandwich panels Ruukki SP2B 80X-PIR

Thickness, mm10010080
Energy efficiencyLowHighVery high
Thermal resistance of the structure, taking into account cold bridges R0 at 25 °С, m2*K/W2.152.273.79
Heat transfer coefficient U at 25 °C, W/(m2*K)0.470.440.26
Heat lossHighAverageLow
The presence of cold bridgesYes, linear everyNoNo
Perception of operational loads from hinged structuresFineGreatFine
AppearanceMost often determined by the type of trapezoidal sheetFlat surface with profiling optionsFlat surface with profiling options
Structure tightnessLow, sealant is installed on siteHigh, sealant is installed at the factoryHigh, sealant is installed at the factory
Area required for storage of 100 m2 of facade, m235129
Installation speed of 100 m2 facade by a team of 3-4 specialists, hours2877
All-weather installationImpossiblePossible with restrictionsPossible
Structure weight, kg/m22520.611.2
Installation without cranePossible with restrictionsImpossiblePossible
Fire resistanceEI 30 with restrictionsEI 90EI 15
Corrosion resistanceLow, many centers of corrosion where dust accumulatesHigh, no places for dust accumulationHigh, no places for dust accumulation
The need for protection in an aggressive environmentBoth sides of IWC and claddingThe outer side of the claddingThe outer side of the cladding

Durability, years

Up to 20 limited by the service life of the applied sealants and thermal insulation tapeOver 50Over 50

Warranty, years

Up to 10
for some items
Up to 30
for the structure
Up to 30
for the structure
Operating costs for the building (heating, air conditioning, repairs, etc.)HighMediumLow
Materials cost*, €/m240.348.339.0
Installation cost*, €/m212.011.49.6
Total construction cost with installation*, €/m252,359,748,6

* Prices are valid as of the date of writing the article


Given the significant advantages of sandwich panels over IWC, it can be concluded that it is advisable to use internal wall cassettes for temporary facilities or in the construction of buildings that have lower requirements for energy efficiency and durability. With increased requirements for fire resistance, it is recommended to use sandwich panels with mineral wool, and to achieve highest energy efficiency, it is recommended to use sandwich panels with PIR core.

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What is better: internal wall cassettes or sandwich panels?
What is better: internal wall cassettes or sandwich panels?