Introduction
In the world of sustainable construction, choosing the right thermal insulation plays a crucial role in determining a building’s energy efficiency, indoor comfort, and environmental impact. In recent years, aerogel has emerged as an advanced material thanks to its extraordinary insulating properties combined with extremely thin thicknesses. But is it always the best choice?
In this article, we analyze the comparison between aerogel and traditional insulation materials such as EPS, XPS, rock wool, and polyurethane. We will explore which insulating material is most advantageous based on thermal conductivity, costs, minimum thickness, and real application scenarios like historic building renovations or internal wall insulation with limited space.
1. What is Aerogel?
Aerogel is a material derived from a gel in which the liquid component is replaced with gas, maintaining a solid nanoporous structure. The most common is silica aerogel, known as one of the lightest and most insulating solids worldwide. Thanks to its extremely low thermal conductivity (around 0.013–0.018 W/m·K), it delivers excellent performance even at minimal thickness.
Key characteristics:
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Thermal conductivity (λ): 0.013–0.018 W/m·K
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Extremely lightweight
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High fire resistance (Class A1)
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Hydrophobic and moisture resistant
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Ideal application thickness: 1 to 3 cm
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Perfect for thin thermal insulation needs
2. Technical Comparison: Aerogel vs Other Construction Insulation Materials
| Material | λ (W/m·K) | Thickness for R=2 (m²K/W) | Fire Resistance | Minimum Thickness | Average Cost €/m² |
|---|---|---|---|---|---|
| Aerogel | 0.013–0.018 | 2–3 cm | Excellent (Class A1) | 10 mm | 120–250 € |
| EPS (Polystyrene) | 0.030–0.040 | 6–8 cm | Low (<100°C) | 40 mm | 15–25 € |
| XPS | 0.029–0.035 | 6–7 cm | Medium | 30 mm | 20–30 € |
| Rock Wool | 0.034–0.045 | 7–9 cm | Excellent | 40 mm | 25–35 € |
| Polyurethane (PUR/PIR) | 0.022–0.026 | 4–5 cm | Medium | 20 mm | 35–60 € |
This comparison clearly shows how aerogel is the best thermal insulator per millimeter of thickness, albeit at a higher cost. It is ideal for interventions where space is limited or where high-performance thin insulation is required.
3. When is it Worth Using Aerogel?
Aerogel is not intended to fully replace traditional insulators but is the ideal solution in specific cases:
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Renovations of historic buildings, where external insulation is impossible and internal space is limited.
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Apartments in condominiums where every centimeter of living area counts.
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Internal wall insulation with limited thickness, without compromising usable space.
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Buildings with architectural restrictions that prevent facade modifications.
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High humidity or mold-prone areas: aerogel offers high breathability and water resistance.
For these needs, aerogel is confirmed as the best thin insulation available on the market today.
4. Limitations of Aerogel
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Higher cost compared to other insulators (up to 10 times more expensive)
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Requires specialized personnel for specific applications (e.g., thermal plasters like Thermo-Coll)
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Not suitable for buildings with ample available thickness and limited budget
5. Practical Case: Internal Insulation with Aerogel in a Historic City Center
An apartment in the historic center of Zadar was internally insulated with a 2 cm thick aerogel-based thermal plaster. Results:
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28% reduction in energy consumption in the first year
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No significant reduction of living space
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Energy class improved from D to B
This case demonstrates how aerogel is perfect for internal thermal insulation in tight spaces.
6. Conclusion: Aerogel, Next-Generation Thermal Insulation
Aerogel represents a top-tier solution for thermal insulation, ideal in contexts where space is limited or extreme performance is required. For those needing insulation in just a few centimeters, without compromising aesthetics or breathability, the investment translates into long-term energy savings, improved comfort, and higher energy efficiency.
Contact us to find out if aerogel is suitable for your project