Structural Timber Association                            SBE0003

Written evidence from the Structural Timber Association

• To what extent have the Climate Change Committee’s recommendations on decarbonising the structural fabric of new homes been met? The construction industry has focussed its attention on operational carbon with little or no attention to embodied carbon and this needs to change now. A fabric first approach to operational carbon must be maintained but we need to overcome the industry’s struggle to be able to successfully measure embodied carbon.

• How can materials be employed to reduce the carbon impact of new buildings, including efficient heating and cooling, and which materials are most effective at reducing embodied carbon? The promotion of structural timber in construction is vital in the UK’s target of achieving Net Zero by 2050. With the built environment responsible for 40+% of all emissions it is vital the use of timber is maximised. Life Cycle Assessment must play a huge part in the choice of building materials going forward. We note the recommendation by the Dept. of Environment, Food & Rural Affairs to use more timber in construction.

• What role can nature-based materials can play in achieving the Government’s net zero ambition? The answer to this question mirrors that above as we acknowledge that timber must play a crucial role in the UK achieving its 2050 Net Zero target – we will not achieve it without the use of more timber in construction.

• What role can the planning system, permitted development and building regulations play in delivering a sustainable built environment? How can these policies incentivise developers to use low carbon materials and sustainable design? It is crucial that local planning authorities set target for the use of timber in construction. An example would be the decision by Welsh Government to state that all affordable homes built in Wales from 2022 must be timber frame. To achieve this, they have set up a consortium of 11 councils and 14 timber frame manufacturers to provide a collaborative programme to achieve this. Other examples of leadership in this area are Hackney Council and their Timber First policy and Exeter Council and their drive for passivhaus. It is recommended that ALL planning applications should include a climate declaration to ensure it is considered as a discipline.

• What methods account for embodied carbon in buildings and how can this be consistently applied across the sector? A cradle-to-cradle approach should be used to ensure that ALL carbon emissions are considered. Currently whilst there is some convergence of measurement is evident, interpretation is still a major concern and a consistency of methods must be applied. In other words, a clear and obvious level playing field must be visible and apply to all concerned.

• Should the embodied carbon impact of alternative building materials take into account the carbon cost of manufacture and delivery to site, enabling customers to assess the relative impact of imported versus domestically sourced materials? The impact of embodied carbon must be considered at all stages of a building materials’ life including manufacture and delivery to site. All matters that influence global warming should be included but it is important we do not bring about double counting i.e. we must agree where the figures preside when it comes to imports/exports.

• How well is green infrastructure being incorporated into building design and developments to achieve climate resilience and other benefits? There are very few examples of people walking the walk. There are far more examples of people talking the talk, but it needs to become standard practice. Historically a BIM solution was promised but does not appear to have materialised. If a BIM model was able to predict the carbon emissions in advance of any building taking place choices could be made to change what materials are used long before the construction process.

• How should we take into account the use of materials to minimise carbon footprint, such as use of water harvesting from the roof, grey water circulation, porous surfaces for hardstanding, energy generation systems such as solar panels? In essence a far more holistic process is required at the design stage to consider full operational and embodied carbon statistics. Currently designers meet current regulations so these need to change accordingly to consider our Net Zero target.  It is recommended the CIBSE report on how many of the building products on offer to reduce operational carbon are high in embodied carbon during manufacture.

• How should re-use and refurbishment of buildings be balanced with new developments? Before any new build takes place, a client should always ask if current assets may be re-used. An exercise should take place to include a measurement of carbon between new build and re-use and the structural timber sector has a range of products and systems to meet both.

• What can the Government do to incentivise more repair, maintenance and retrofit of existing buildings? Consider removing or reducing VAT, provide funding e.g. Green Deal (but with a coherent strategy) and consistent leadership with the CLC National Retrofit Strategy a good example.

April 2021