Specifying construction materials
Building materials affect how buildings breathe, their thermal performance and their embodied energy. As materials age, their appearance as well as their performance is affected and this needs to be considered at the design stage. Replacement, upgrading and maintenance can be challenging when materials are not easily accessible, or in those cases where there is no like for like replacement. Indoor air quality, the acoustic performance and sick building syndrome are frequently discussed when considering materials, as they can affect the health and productivity of the building occupants.
To an extent, technological advances and manufacturing of innovative products can help respond to these challenges. However specifying materials considering their thermal properties, such as their thermal transmittance (u-values), and ensuring they are properly detailed to avoid thermal bridging at junctions, are key factors to creating a comfortable environment and reducing the heating needs of the internal spaces.
While heating has the most significant contribution to the greenhouse emissions of buildings, materials can support mitigation in other ways too: for instance through considering whether they are renewable like timber, or finite like stone. Within that, it is worth exploring the possibilities of reusing them or recycling them to minimise construction waste, and also of upscaling lesser quality source materials to produce higher quality ones, as is the case for timber I-Joists for example. It’s worth noting that natural building materials require less energy intensive processes to achieve good performance levels compared to manmade ones, and that is reflected in their embodied energy. Whether they are produced locally or imported also has a role to play: Locally sourced materials need to travel less between the location where they are produced and their destination and could help reduce our carbon footprint. This is not a lesser concern, as according to the recently published Climate Change Plan, housing alone is responsible for 32% of Scotland’s carbon footprint.
Where to look for information and support
A good source of information on construction materials is the Green Guide online, by BRE where building materials and components are assessed in terms of their environmental impact across their entire life cycle – from ‘cradle to grave’, within comparable specifications.
Architecture and Design Scotland has recently launched an online resource complementing its Library of Sustainable Building Materials which is based at The Lighthouse, Glasgow. This is produced in partnership with BRE, CSIC, Zero Waste Scotland and Forestry Commission Scotland and showcases sustainable, traditional, innovative, recycled and low carbon building materials.
Scottish Government provides financial and technical support which is targeted to the poorer performing existing homes, and intends to increase the take-up of home energy efficiency measures, reduce fuel poverty, while also help reach our emission reduction targets.