Retro EcoWall





Careful consideration is required when retrofitting traditional buildings with solid stone or brick walls. Aside from providing thermal comfort, it is essential that the insulation promotes breathability in the walls and manages moisture. In response to these requirements, Ecological Building Systems has launched the Retro EcoWall® internal wall insulation system, which was ‘highly commended’ in the RIAI Architect’s Choice Awards 2022.

Challenges with traditional buildings

On hard-to-treat traditional walls, it is important to ensure the thermal solution is compatible with the existing wall, not only thermally, but from a moisture management perspective also. Traditional walls are often uneven and require significant preparation to level prior to being internally insulated. This can lead to extended lead times and increased costs, along with the loss of precious internal space.


Retro EcoWall® provides a comprehensive solution to this by combining capillary active cork lime thermal plaster with moisture open woodfibre boards. Remaining true to the ethos of achieving ‘better building’ by adopting a ‘fabric first’ approach to design, breathable lime plaster and natural paint are then applied to complete the system.

Lower U-values without compromising breathability

A key benefit of combining insulating plaster with woodfibre is that lower U-values can be attained with smaller thicknesses. For example, combining just 30mm of Diasen Thermactive cork lime insulating plaster with 60mm Gutex Thermoroom woodfibre boards improves the U-value of a traditional stone wall from 2.38 W/m²K to just 0.35 W/m²K.

Likewise, using the same products on a traditional brick wall, only this time with 20mm of Diasen Thermactive, would see the U-value improve from 2.19 W/m²K to 0.39 W/m²K. The complete Retro EcoWall build-up has also been verified using WUFI hygrothermal modelling on numerous projects by independent consultants and by the Ecological Building Systems technical team.

Quadcore Kingspan

Key benefits of Retro EcoWall®

  • A complete specification solution: combining the unique properties of insulating cork and lime with wood fibre insulation
  • Retains the breathability of traditional walls and protects against condensation, mould and building deterioration.
  • Uses natural insulating materials with EPDs
  • Achieves low U-values with the optimum use of space
  • Quick installation time

Embodied Carbon Emissions

As embodied carbon emissions come more into focus, low-carbon thermal solutions will be essential in the drive to bring traditional buildings back to life. If you are retrofitting a traditional building and would like to learn more about Retro EcoWall®, or need advice on any of the products mentioned, get in touch to speak to one of our highly-trained technical team at

Alternatively, the detailed installation video below tells you all you need to know about installing the Retro EcoWall® system

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