As part of our Carbon Matters series, over the coming months we will be posting about some key projects that are shaping our understanding of, and approach to, sustainable design. These projects vary from retrofit of an 18th century castle, to off site manufacture of Scotland’s first home grown CLT structure. As part of our commitment to reducing the carbon emissions from our work, we want to share our experience and approach, so collectively we can develop our thinking towards a more sustainable future.

In 2021, working with Ecosystems Technologies, we completed the first Scottish homegrown Cross Laminated Timber (CLT) structure in the UK. The project involved the construction of six “study pods” for Fettes College in Edinburgh. The pods sit nestled between the mature tree lined boundary of the college and their Craigleith boarding house. They provide study space for day students at the college.

The floors and walls of the pods are constructed from CLT, with the roof deck constructed from nail laminated timber (NLT). CLT offcuts were used to make the fitted study desks, partitions and shelves reducing waste, while also creating a cosy internal environment. The CLT and NLT were made at BE-ST in Hamilton just outside Glasgow from Scottish grown timber. While ground works were undertaken, the pods were prefabricated at Ecosystems factory which allowed for a high quality, airtight construction. The pods are insulated using bio-based woodfibre and cork insulation, and are then clad in timber cladding. The extensive use of timber products, and the sourcing of local materials meant the embodied carbon emissions were very low, calculated at 373 kgCO2e/m2. This sits in the ‘A’ category of the LETI embodied carbon targets for educational buildings. While we acknowledge this is a simple, single storey structure, it is a positive step in our journey to changing how we construct our buildings to reduce carbon emissions.