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Transparent heat-reflecting coatings for buildings

Transparent indoor wall coating that reflects heat and improves thermal comfort

HeiQ Xpectra is a transparent, sprayable coating for interior walls that reflects heat radiation back into the room. It can reflect up to 74% of incident heat radiation and improve wall insulation behavior (U‑value) by up to 25%, while keeping the surface look unchanged.

 

 

Key benefits

  • Ultra‑low VOC emissions for indoor use, far below AgBB 2024 limit.
  • Water‑vapor permeable, diffusion‑open (sᵈ < 0.01 m, DIN EN ISO 7783).
  • Fast application with standard spray equipment
  • Transparent and stable, no color change after 1,000 hours QUV testing.
  • Designed for professional indoor retrofits where added insulation thickness is not desired.
HeiQ Xpectra heat reflection
Thermal imaging vs. real view highlighting how the coating reflects heat radiation instead of absorbing it.

Applications

HeiQ Xpectra integrates into existing buildings and renovation projects without structural changes. It reduces heat loss through interior walls and improves thermal comfort across a wide range of applications, while preserving the original design.

  • Residential buildings

    For interior wall surfaces in existing homes to improve thermal comfort and reduce heat los.

  • Commercial and public buildings

    For offices, schools, and public interiors needing fast energy upgrades with minimal disruption.

  • Building renovation projects

    For improving thermal performance without changing façade geometry or adding insulation thickness indoors.

  • Energy‑efficiency upgrades

    Suitable for humid rooms when the substrate is dry before application, due to diffusion‑open behavior.

  • The science behind the HeiQ Xpectra coating for buildings

    HeiQ Xpectra for walls is a micrometer‑thin low‑e coating with wire‑like, microscale heat‑reflective particles embedded in a silicate bin...

    HeiQ Xpectra for walls is a micrometer‑thin low‑e coating with wire‑like, microscale heat‑reflective particles embedded in a silicate binder. Independent testing validates an emissivity of 0.26 ± 0.02, which is the basis for its heat‑reflection effect. HeiQ Xpectra is also integrated into the WUFI® software to support thermal and moisture simulations for building materials.

    HeiQ Xpectra metal wires
    Wire‑like, microscale heat‑reflective particles embedded in a silicate binder.

  • Frequently Asked Questions (FAQ)

    • What is HeiQ Xpectra for walls used for?
    • Which independent tests and standards support the performance claims?
    • Is the coating safe to apply indoors?
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    HeiQ Xpectra for walls is designed for interior wall and ceiling applications to reduce heat loss by reflecting heat radiation back into the room. It is not intended for flooring or exterior walls.

    Emissivity and reflective properties are validated by CAE, water‑vapor permeability is measured by Fraunhofer IBP (DIN EN ISO 7783, sᵈ < 0.01 m), and VOC emissions are tested by eco‑INSTITUT to AgBB 2024 (<5 µg/m³ after 28 days, far below the ≤1,000 µg/m³ limit).

    Yes. HeiQ Xpectra is designed for indoor application by professionals. During spraying, standard protective equipment is required, as with conventional coatings. Once dry, the coating is immobilized on the surface and permanently bonded.

  • News: HeiQ Xpectra wins German Sustainability Award 2026

    HeiQ Xpectra, a breakthrough transparent coating that improves building energy efficiency and reduces CO₂ emissions, has been named as winner of the German Sustainability Award for Products 2026 in the climate transformation field.

    HeiQ Xpectra, a breakthrough transparent coating that improves building energy efficiency and reduces CO₂ emissions, has been named as winner of the German Sustainability Award for Products 2026 in the climate transformation field. This prestigious recognition honors HeiQ’s role in accelerating climate transformation through scalable innovation that enables fast, cost-effective retrofits without compromising aesthetics.

     

    Energy efficiency made simple 

    HeiQ Xpectra is a transparent coating designed to reflect heat and thus improves the energy efficiency of buildings without requiring costly construction work. The coating reflects up to 74% of heat radiation and can improve the heat transfer coefficient (U-value) of walls by up to 25%, which significantly reduces heating and cooling requirements. Its simple application as a spray coating makes it particularly easy to retrofit in existing buildings and opens up great scaling possibilities. The certified very low VOC emissions and local production contribute to better indoor air quality and lower transport emissions. 
     

    Global testing and partnerships 

    The technology has been launched for concrete walls at the BAU tradeshow 2025. Ongoing collaborations with HeiQ Xpectra partners have been crucial to its success: LEONHARD KURZ contributed expertise in advanced coating formulations, and CAE, the Center for Applied Energy Research in Würzburg, Germany, provided performance testing to validate energy efficiency and durability. First results from testing in Thailand indicate significant potential for improving thermal comfort in tropical climates, supporting energy savings for space cooling. 
     

    From vision to impact 

    The award jury recognized HeiQ Xpectra for its transformative potential in climate action, citing its ability to reduce CO₂ emissions, conserve energy, and support resource efficiency. The product’s development was driven by a clear narrative: turning the global retrofit challenge into a practical climate solution. By replacing traditional renovation with a high-performance coating, HeiQ empowers building owners to act swiftly and sustainably. This achievement reflects the dedication of the HeiQ team and its partners. As noted by Dr. Oliver Zech, CEO of HeiQ RAS AG: “The German Sustainability award is a success example for HeiQ as deep tech material innovator andto our shared commitment to innovation and sustainability. The award strengthens our position in the market and opens new opportunities for collaborative commercialization.” 
     

    Scaling for the future 

    HeiQ plans to scale HeiQ Xpectra across Europe, North America, and Asia-Pacific, targeting the global retrofit sector and industrial applications. The product is designed to support compliance with green building standards, and future developments will enhance its usability and aesthetic versatility. The award will be formally presented on December 4, 2025, at the Maritim Hotel in Düsseldorf. HeiQ looks forward to participating. 
     

    About HeiQ Xpectra 

    HeiQ Xpectra, part of the HeiQ Group and headquartered in Regensburg, Germany, develops advanced functional coatings for sustainable, high-performance applications. Its flagship coating is a transparent, heat-reflective technology that enhances energy efficiency and reduces CO₂ emissions in buildings, while also enabling transparent electrodes for organic photovoltaics, transparent low e coatings, e.g. green houses, and signature management. Designed for scalability and versatility, HeiQ Xpectra combines scientific expertise, rigorous testing, and strategic partnerships to deliver coatings that address global challenges in energy, sustainability, and security. Learn more: www.heiq.com/ heiq-xpectra/

     

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    20251120_XP_Winner German Sustainability Award 2026_PRESS RELEASE

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