A decision support framework for optimal local delivery of zero-carbon housing in England

In the UK, residential housing represents a significant target sector for carbon emission reductions. New build housing is central to this effort due to the relative ease of building-in energy efficiency measures coupled with the long lifetimes of housing once built. Within England, performance improvements have mainly been implemented through incremental changes to the Building Regulations. In lieu of national regulatory change, a key policy mechanism for the improvement of new-build housing performance has been through local level planning policy. However, current implementation and usage of these powers is heterogeneous across England. Little research exists seeking to understand the factors limiting more homogeneous use of these powers, and thereby more uniform implementation of incrementally improved performance standards for new build housing. Further, research of methodologies to aide local authorities in making informed decisions within this area is also limited. This research aims to develop a new framework to aid Local Authorities' provision of cost-effective solutions to zero-carbon development, to achieve this the research aims to first investigate and assess factors impacting the adoption of carbon reduction policy at a local level in England. In this way, the research aims are twofold. The research utilised a sequential mixed method design to assess factors impacting the adoption of carbon reduction policy at a local level in England. Data was gathered through a cross-sectional online questionnaire administered to all local authority planning policy teams within England, and semi-structured interviews with personnel involved within local authority planning policy related to new-build housing and sustainability. A framework was then developed to aid local authorities' provision of cost-effective solutions to zero-carbon development. This framework utilised dynamic thermal simulation, and multi-objective optimisation to provide decision support. The developed framework was then experimentally tested to determine potential benefits of such an application. Key findings that emerge from this work encompass four interrelated stands: (1) It is found that uncertainty following the withdrawal of national level agendas has led to a policy void for many local authorities, with many now suffering from a lack of policy power to enforce lower carbon standards; (2) financial viability is identified as an additional driver of heterogeneous policy adoption throughout local authorities in England; (3) technical limitations are identified within local authorities acting as barriers towards the monitoring and thereby implementation of carbon mitigation policy at a local level; and (4) the application of a novel non-linear decision support strategy applied to local level carbon reduction policy demonstrates up to around 30% reduction in emissions without impact on financial viability. This work represents a unique exploration of local level policy relating to carbon emissions in new-build housing, and further, represents a novel application of decision support to this problem area. The main recommendations relate both to policymaking, such as actions towards enabling the reduction of barriers to allow more homogeneous policy adoption for carbon mitigation in new-build housing, and to research, such as towards the further development of decision support methodologies within this problem domain.