The Building Conservation Directory 2024

69 CATHEDRAL COMMUNICATIONS THE BUILDING CONSERVATION DIRECTORY 2024 ROOFING 3.1 PRESERVING VERNACULAR DETAILS ROSS CAMERON and JENNIFER FARQUHARSON AT its core, vernacular building is about local knowledge and local materials. Historically, the communities who lived in these buildings had a deep connection with them as they were the ones who built them; much of their time would then have been spent on maintenance, which often involved growing and sourcing materials. It’s this connection to and knowledge of their natural environment that informed and shaped a community’s vernacular heritage. While it’s extremely important for us to keep traditional and vernacular building skills alive to protect our historic buildings and to recreate others lost to time, it’s also clear to us in Historic Environment Scotland that we can all learn from these buildings and their use of locally sourced building materials as we work towards a more sustainable future. So, why are vernacular buildings so sustainable? LOCALLY MADE The characteristic features of vernacular buildings are often obvious, for example, thatched roofs, earthen walls and cruck frames, but it’s easy to forget why these materials were used. Historically, transporting goods was incredibly difficult, whereas sourcing local materials was much easier. Finding workable material near a site was often a deciding factor on where and what you built. Whether it be stone, turf, thatching material or timber, having a steady supply close by was essential. Today, we can have many materials delivered to site from all over the world with relative ease. But with this has come many unsustainable and unethical practices that contribute to climate change and the immense amounts of waste in the building industry. Sourcing material locally ensures that good quality materials are used sustainably. For example, sourcing hazel for building is done by coppicing (an ancient woodland management technique used to ensure a regular supply of timber and firewood). Only the appropriate amount is taken, and the rest is left to continue growing. BUILT FOR LOCAL CLIMATES Although builders of the past did not have to contend with the accelerating effects of climate change as we do today, they did have to deal with difficult weather conditions that necessitated a deep understanding of materials, their scarcity and their efficient use. In many cases, vernacular builders of the past lived in houses they built. They had a keen understanding of the conditions they would face and unique knowledge of their site that helped them tailor the building to their needs. Designs and details evolved through trial-and-error spanning generations before settling on a tailored solution that suited their location. The thick walls of Hebridean blackhouses were packed with earth to combat high winds, the steep thatched roofs seen throughout the Highlands were designed to carry heavy rain away from the walls, and sheilings (huts) were deliberately built into hillsides and orientated with low exposure to minimise the effects of difficult weather. REUSED AND RECYCLED Recently, steps have been taken to encourage the reuse of building components to save the carbon embodied in their existing materials, and the ‘design for deconstruction’ movement urges that buildings be designed with efficient dismantling and reuse in mind from the beginning, ensuring materials can continue to be productive far past their initial use. Scarcity of materials, combined with the effort required to collect and process them, ensured that very similar ‘circular’ practices were commonplace in vernacular construction. In the Highlands, as timber became increasingly expensive, it was standard practice for families moving from one area to another to bring their roof timbers with them and source stone at the new location. In the Hebrides, where timber was extremely scarce, frames were found in ruins made from non-native tree species popular in the boat building industry. Wrecked or decommissioned boats had been salvaged for their timber, turning the distinctive curve of their hull into crucks for buildings. It was the scarcity of materials, combined with the effort required to collect and process them, that ensured these efficient circular practices were well embedded within vernacular buildings. MORTARS Vernacular masonry buildings are often found to have been built using earth or clay for both mortar and surface finishes, particularly in areas where limestone was unavailable. Lime and other materials like timber, straw and stone were also An experimental ‘grassroots’ hut built at Comrie, Perthshire under the direction of the University of Edinburgh as part of a skill training initiative, using materials sourced within 100 metres of the site. These include thick walls of turf on a stone plinth and a roof of timber poles thatched with bracken. (Photo: Matt Cartney, Historic Environment Scotland)