House building in Scotland: The sustainability performance gap

The construction of very low carbon new homes in Scotland is soon to be mandatory. Despite considerable investment, numerous reports and a deferment, there remain serious question marks over the domestic sector's capability, capacity and motivation to deliver as standard very low carbon homes. The difference between low carbon design and actual building performance has arguably dominated the debate. The 'performance gap' as it has commonly become known, is only one measurement of industry readiness. For successful design and delivery of very low carbon homes, a holistic evaluation of house building in Scotland is required. This is a position paper, exploring the challenge of constructing very low carbon housing. Contrary to the traditional interpretation, the performance gap in the delivery of sustainable domestic construction is arguably threefold; (1) Environmental: the difference between fabric design, thermal performance and resultant energy consumption, (2) social: the gap between supply and consumer demand and (3) economic: the disparity between the economic rewards and the incurred cost of sub-standard delivery. Evidence from previous studies indicates that whilst the notion of very low carbon housing is widely commended and has generated many successful design strategies, the best ways for the industry to deliver the build to the required level remains highly debatable. The low carbon challenge is frequently expressed in 'green', 'sustainable' and 'environmentally friendly' vernacular. Reviewing the literature, this is arguably misleading and a rather gracious evaluation of current industry performance. If, in essence, sustainability ideals are quality ideals then questions need to be asked about construction procedure, process and performance. Addressing the environmental, social and economic performance gap(s) will in all probability require further government intervention, but it may also require a fundamental re-evaluation of sustainable domestic construction and the evolving role of legislators, designers, contractors, consumers and end-users.