Professor Sandy Halliday CEng Hon FRIAS

Professor Sandy Halliday CEng Hon FRIAS - Principal

Gaia Group Ltd


For the circular economy to be compatible with future-proofing our attitude to building materials and manufacturing must change profoundly. Current policy to divert Construction & Demolition Waste (CDW) from landfill aims to contribute to the ‘circular economy’ - an economic system aimed at eliminating waste. This end-of-pipe solution justifies economic activity at the expense of externalities and presents a burden to future generations.

Our CDW recycling target is easily achieved against a growing volume of actual CDW. Reprocessing creates pollution embeds toxins and downcycling undermines intrinsic qualities and value. The circular economy policy must not simply reduce landfill and camouflage polluting industries but support clean manufacturing. Cradle-to-cradle ready products and materials that can be safely reused must become the norm.

However, our sector responsibility for waste goes far beyond materials. Waste and pollution occurs at every stage in the building life cycle; at planning, design, material selection, construction, occupation and deconstruction. At planning the prevalent house building concept enforces inefficient behaviours with low-density housing on sites remote from social and transport infrastructure or public amenities. It promotes waste of energy, time and money and eats up valuable green space whilst offering no bio-diversity response.

There is concern over mental and physical health – societal waste - implications of these barren environments. Waste occurs on-site, through inefficiency, over-ordering, adverse weather, travel and transportation. Waste in use occurs through less than optimal performance. Design life is too short. We must also address refurbishment and re-using existing buildings to avoid demolition and minimise new build.

Business as usual cannot continue. Planning, specification, construction, occupation and disposal of buildings must be tackled to prevent undermining our Net Zero ambition. This affects location, massing, size, lifetime, supply chains, materials, products, social networks, ecology and user behaviours.

Mainstream devices – education, training, enforceable regulation and policy – are required to create mainstream change. Current Building Standards state that they cannot adequately cover “location and transport” and that “material sourcing and embodied energy are inappropriate due to complexity”. These goalposts need to move to support net-zero. To fail to take account of our current perilous predicament, and the scale of the response required would be another waste. Time and opportunity are amongst our most precious resources and to waste them would be tragic.

“Everything Must Go Somewhere” –Commoner 1971

Speaker biography

Sandy is a chartered engineer and highly respected author and communicator with extensive experience of inter-disciplinary working. She has researched and advised on sustainable built environment issues since 1986.

Sandy’s consultancy work extends to advising on strategies to create healthy, resource-efficient buildings and places that demonstrate best value, support communities and enhance biodiversity.

As Professor of Engineering Design for Sustainable Development at Strathclyde, she developed her research experience into a training programme in Sustainable Design now the highly acclaimed Sustainable Construction, 2nd Edition, with 120 best practice case studies covering policy, cost, measurement, materials, environmental design, urban ecology and more.

In 2018, she was given Honorary Fellowship of the RIAS for services to sustainability and the built environment. She currently teaches on the Energy & Environment Programme at the University of Oslo International Summer School.

She will discuss her recent research for Zero Waste Scotland.

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