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Interior of a building undergoing renovation; craftsmen apply insulating plaster for interior insulation.

Effective interior insulation with insulating plaster

Interior insulation – the strong alternative when exterior insulation is not possible

It is not always possible to insulate a building from the outside—for example, in the case of listed facades, insufficient clearance, or when only certain areas are to be renovated. In these cases, interior insulation offers a technically sophisticated, economical, and often even smarter solution. When properly planned and professionally installed, it reliably achieves the energy-saving goal—including protection against mold and moisture.

When is interior insulation recommended?

  • Preservation of historical monuments and facades: Historical views remain unchanged.
  • Building regulations: Building lines or fire safety distances rule out external insulation.
  • Partial renovations and owners' associations: Individual apartments or units can be upgraded separately.
  • Temporarily used spaces (e.g., churches, halls): Faster and more cost-effective heating – without heating the entire building mass.
  • Thermal bridges & moisture problems: Reveals, interior wall connections, or corners are thermally improved; condensation and mold risks are reduced.
  • Intact facade: No permits, scaffolding, or interventions in the outer shell are required.

Our product recommendation for optimal interior insulation

Insulated interior of the coin arcades: insulating plaster on the inside

Material selection: Why mineral thermal insulation plasters score highly

Mineral insulation plasters offer decisive advantages for interior insulation:

  • Homogeneous wall cross-section without cavities – no “condensation pockets.”
  • Capillary-active & moisture-regulating – supports a dry, mold-resistant building component.
  • Thin layer thicknesses – minimal loss of space, high design freedom.
  • Clean details on reveals, corners, and connections – visually and structurally elegant.
[Translate to English:] HASIT Fixit 222 Dämmputz – unsere Produktempfehlung für eine effektive Innendämmung

Top product: HASIT FIXIT 222 high-performance insulating plaster

Our most efficient insulating plaster for interior use:

  • High insulation effect even with thin layers – ideal when every centimeter counts.
  • Targeted thermal bridge mitigation: On integrated components (e.g., partition walls, reveals), the surface temperature in “critical” areas can be effectively raised by applying a narrow strip of plaster – often without additional wedge solutions.
  • Mineral, diffusion-open, capillary-active – for permanently reliable interior insulation systems.

More about our HASIT FIXIT 222

Renovated interior of the Franciscan monastery in Zeitz
Insulating plaster is applied to the window arch – for optimal interior insulation.

Our insulating plasters – proven in interior insulation

Our high-performance mineral insulation plasters have proven themselves in practice as an efficient solution for interior insulation. Two references impressively demonstrate how energy-efficient renovation can be achieved with minimal loss of space and a high degree of design freedom.

[Translate to English:] Sanierte Münzarkaden mit neuer Innendämmung.

Coin arcades, Maximilianstraße, Munich

The preservation order required the historic facades to be retained – classic interior insulation systems would have achieved the required U-value, but would have resulted in a noticeable loss of space – a significant disadvantage in this high-priced city center location. The HASIT Fixit 222 aerogel high-performance insulating plaster provided an elegant solution: a layer thickness of just 2 cm was sufficient to achieve the desired U-value and preserve valuable usable space. Curves and reveals could be formed without thermal bridges and without wedge solutions – a powerful combination of efficiency and design.

Learn more about the Münzarkaden in Munich

Front view of the revitalized administrative building in Gotha: Listed building shines in new splendor after extensive renovation.
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Plastering & Insulating

Effective thermal insulation

Discover more about our lime insulation plasters for renovation—efficient, environmentally friendly, and future-proof. Less CO₂, more living comfort: In our theme world, you can find out how modern insulation technology contributes to effective thermal insulation—and makes a real difference.

To the theme world