The following case study details a re-rendering project that is the first of its kind, EEH-Solutions taking the challenge within Letchworth Garden City, a heritage site. The ensuing project was a re-render and External Wall Insulation (EWI).
WHAT IS THE SIGNIFICANCE OF THE CONSERVATION AREA?
EEH-Solutions have gained license to work on various dwellings directly from the Letchworth Garden City (LGC) Heritage Foundation, as any unapproved maintenance can lead to a complete removal of the home’s historical value.
Any proposed changes by the homeowner and subsequent contractors must meet certain criteria according to the Letchworth Scheme of Management and Design Principles. This applies to all freehold premises within the Letchworth area, highlighting the restrictions on various home alterations (e.g. tree removal). Design Principles relate to the guidance of how an alteration should be conducted, split between the Heritage Character Area and Modern Character Area.
THE CHALLENGE
Undertaking the trial to insulate two homes within the heritage site, EEH-Solutions found that the previous concrete render was produced nearly one hundred years ago, sometime in 1920. Any new render applied must, therefore, replicate the original aesthetic.
However, due to the age of the render, it was hacked away to find the original substrate used during the early 20th century. After uncovering the substrate of the first home, we discovered that there was a mixture of varying substrates, blockwork and calcium silicate brickwork, indicating that the house had been rebuilt. The original heritage was unknown.
Overcoming this hurdle, EEH-Solutions carefully sourced a product that was suitable for this mix of substrate - the decision landing on a first-time-use cork and lime based render: Diathonite, with its own energy efficiency qualities such as thermal and moisture regulation.
This render was then applied to the front and alleyway of the building, while additional Webertherm XP system rockwool insulation boards were applied to the back - creating a hybrid. All of which provides additional insulation and structural integrity to the home – discreetly modernising the structure without erasing its original history.
Throughout the entire process, EEH-Solutions was in communication with the LGC Heritage Team to confirm that our methods align with the Letchworth Scheme of Management and Design Principles. Our team consistently showcased a variety of patch tests utilising Diathonite as a new material, demonstrating its compatibility and innovation.
EEH-Solutions and the LGC Heritage Team had a mutual agreement that the home will retain as much character as possible, going as far to apply the diathonite render by hand to uphold history.
Ultimately, the final finish was argatherm, a lime-based render mechanically sprayed atop the diathonite, which also inherits insulation properties. At the back of the property, EEH-Solutions mechanically sprayed a Weber M1 render that mimics the argatherm finish - creating a smooth transition.
Overall, the process was both challenging and rewarding – the work providing us with excellent experience as to tackle future challenges and heritage site projects. The LGC Heritage foundation can now utilise our project as guidance for the home improvement of buildings across the city. This showcase of our work is proof that, despite potential difficulty, retaining historical integrity through rendering is possible.
If you want to know more about our commitments, contact EEH-Solutions today to discuss how we can help you.
Emily : Nov 20, 2024 3:26:16 PM
