IHBC’s new edition of its members’ journal Context is out – No. 185 –and for this round we feature Soki Rhee-Duverne and Jim Hart on ‘A carbon case for indigenous slate’.
IHBC writes:
The fact that UK slate can offer clear embodied carbon advantages, primarily due to lower transport emissions, will influence the choice of roofing material for historic buildings.
Soki Rhee-Duverne and Jim Hart write:
Natural slate has long been the roofing material of choice for many of the UK’s historic buildings, prized for its longevity, weather resistance and continuity with local building traditions. Yet the domestic slate industry has experienced a dramatic decline since the 19th century, with most slate used in the UK today now imported, primarily from Spain. This downturn has been driven by competition from cheaper imports, the closure of local quarries, loss of craft skills, changing construction practices favouring lighter and lower-cost modern alternatives, and regulatory challenges that limit the reopening or expansion of extraction sites.
While the idea of conserving historic fabric using traditional materials is well established, the environmental case for those materials has become increasingly important. As aware- ness grows around the climate impacts of construction, embodied carbon (the emissions associated with extracting, processing, transporting and disposing of building materials) has become a key consideration, particularly in the retrofit and repair of existing buildings.
In response, Historic England and Historic Environment Scotland commissioned a study to examine the embodied carbon of roofing slate, with the primary aim of supporting the case for using indigenous slate for repair of historic buildings. The motivation was that if UK slate could be shown to offer environmental as well as heritage benefits, this could strengthen demand and help sustain a struggling but culturally important industry.
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This study highlights that UK slate can offer clear embodied carbon advantages, primarily due to lower transport emissions. As sustainability becomes embedded in conservation practice, material choices must increasingly consider both environmental impact and heritage compatibility. Key factors include sourcing, expected lifespan, and suitability for traditional construction methods. However, several limitations in assessing embodied carbon remain. These include the absence of UK EPDs, variations in methodology across data sources, and limited evidence on product durability and real-world transport distances.
Further research is needed to support more informed decision-making. Priorities include the development of UK EPDs, improved data on co-product allocation and construction processes, refined modelling of transport impacts and better understanding of product lifespans. A market study would also be valuable in assessing the capacity of the UK slate industry to meet future demand sustainably.
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Soki Rhee-Duverne is researcher, technical conservation teams, policy and evidence (national specialist services) at Historic England.
Jim Hart is researcher and sustainability consultant at JH Sustainability.
Context 185: CONTENTS
Themed Articles
- Editorial
- Understanding pitched roofs, Madeleine Clark
- A code of practice for slate and stone roofing, Chris Wood
- Reslating an ancient water mill, Terry Hughes
- A carbon case for indigenous slate, Soki Rhee-Duverne and Jim Hart
- Successful solar generation in the historic environment, Morwenna Slade
- Sourcing Scottish slate in the 21st century, Imogen Shaw and Graham Briggs
- The roofscape of Hampstead Garden Suburb, Joe Mathieson
Feature Articles
- Conserving the postmodern legacy of the Sainsbury Wing, Alasdair Travers and Jon Wright
- The sad story of Derby Hippodrome, Derek Latham, Peter Steer and Ashley Waterhouse
Regular & Occasional features & updates
- Briefing
- Out of Context
- Periodically
- The writer’s voice
- Letter
- Law and policy
- Vox pop
- Reviews
IHBC Updates
- IHBC celebrates World Heritage UK’s anniversary, Rebecca Thompson
- Notes from the chair
- Director’s cut
- Inter alia
- New member profile
- New members
Commercial
- Products and services
- Specialist suppliers index
Reading Context helps IHBC members develop their skills across all of the IHBC’s Areas of Competence, and so is a critical baseline in addressing priorities in Continuing Professional Development (CPD)
Access the online archive and see the issue online
See more IHBC background and guidance on IHBC CPD and on how you might use past, current and future issues of Context
See the formal guidance paper on IHBC CPD (scheduled for update)
See more on the IHBC Competences and Areas of Competence
