Oakenstone Design Planning Build employs the perfect blend of solutions in this incredible Listed Building.

Incorporating sustainable practices alongside traditional materials in this extensive renovation has presented unique challenges and opportunities for our clients, who are committed to a faithful restoration of their 18th Century, Grade II Listed farmhouse.  

Wherever possible, sustainable materials and processes have been prioritised to create an authentic, comfortable family home with as light an ecological footprint as possible.

The traditional materials used include lime for pointing and mortar throughout; lime ash floors intelligently combined with foamed glass underfloor insulation; Hempcrete wall insulation; and Ground-Source Heating.  

This combination of ancient and modern respects the building’s history and the planet, protects it for future generations, and enhances its primary function, as a comfortable family home.

In this post, I’m going to focus on just the ground floor (and what’s underneath!).  I’ll write more about Hempcrete and Heating in a separate post.

Foamed Glass Insulation

Foamed Glass (often marketed as Geocell or Glapor) is a strong, lightweight gravel made from foamed, recycled glass.  It offers several benefits, including:

• Excellent Thermal Insulation – to maintain a stable indoor temperature.
• Lightweight and Strong – with a high load-bearing capacity, suitable for various structural applications.
• Moisture Resistant – foamed glass is impermeable to water and prevents damp whilst still allowing the floor and building to ‘breathe’, vital in an ancient building such as this.

In this setting, foamed glass has been used beneath Lime Ash floors to provide breathable insulation in a breathable floor, without compromising the building’s structural or historical integrity.

Lime Ash Floors: Traditional and Durable

Traditional Lime Ash Floors are often found (and required) in historic buildings.  The floor is a mixture of lime, ash, and other aggregates. Benefits include:

• Durability:  These floors are long-lasting and can be repaired easily with similar materials.
• Breathability:  Lime Ash allows moisture to evaporate, regulating and preventing damp issues.
• Historical Authenticity:  Lime Ash floors are often the authentic solution in a historical building repair or renovation.
• Lower Climate Impact:  Whilst still a contributor to C02 emissions, Lime Ash floors have a lighter ecological footprint than a standard concrete floor with modern PIR insulation.

Although, of course, there was no foamed glass in the original subfloor of this 400 year old building, it did have Lime Ash floors throughout, so incorporating them into our renovation will ensure that the building retains its historical character and appearance whilst benefiting from the material’s qualities.

Check back soon to read more about this project and our mindful approach to materials, heritage and sustainability.