By Beverly Quinn, environmental engineer at TÜV SÜD, an international building services engineering consultancy specialising in sustainable MEP (mechanical, electrical and public health), BIM, lighting design, and vertical transportation
AN Intergovernmental Panel on Climate Change’s (IPCC) Special Report states that limiting global warming to 1.5ºC would reduce challenging impacts on ecosystems, human health and wellbeing. To achieve this, human-caused emissions of carbon dioxide would need to fall dramatically from 2010 levels by approximately 45% by 2030, and reach net zero by 2050.
In response to the IPCC’s evidence on climate change and the subsequent school climate change strikes, Scotland was the first country to declare a climate emergency in April 2019. The Climate Emergency Response Group (CERG), which is comprised of leaders from private and public sector, membership bodies and delivery organisations, aims to inform and influence the Scottish Government’s response. The CERG’s proposal for climate action has now been adopted by the Scottish Government to support its target of achieving net zero carbon emissions.
Several of the immediate actions identified and adopted by the Scottish Government relate to the built environment. These included:
• Introducing standards to reduce energy demand and carbon emissions in new buildings by 2021. New homes from 2024 should use renewable or low carbon heat, with non-domestic buildings phasing in this approach from 2024. A net zero-carbon standard will also be established for all new public sector buildings.
• Publishing an updated position in the Energy Efficiency Route Map in December 2019, to accelerate improvements of Energy Performance Certificate (EPC) ratings in homes.
• The introduction of funding by the Scottish Low Carbon Heat Funding Invitation which is designed to accelerate the delivery of large-scale low carbon heat infrastructure projects. Projects can be supported with up to 50% of the total eligible build and installation costs (up to £10 million).
Scotland has set world-leading targets, enforced in legislation by the Climate Change (Emissions Reduction Targets) (Scotland) Act 2019. This requires Scotland to achieve net-zero emissions by 2045, with 75% reductions by 2030 and 90% reductions by 2040.
Scotland has been following the Energy Efficient Scotland – Route Map (May 2018), which lays out intentions to reduce greenhouse gas emissions through more energy efficient buildings and decarbonising heat supplies. The aim is to have near-zero emissions from all buildings in Scotland by 2050, and a 59% reduction in the non-domestic sector by 2032 (based on 2015 levels).
Part of the answer is a low carbon and sustainability led approach to building design, to minimise carbon emissions and deliver a better environment for us all to live in. Commercial building design solutions should therefore go beyond achieving a ‘pass’ under Section 6.1(which relates to carbon emissions) of the Building Standards technical handbook 2019: Non-domestic.
Another consideration is that estimated energy usage and carbon emission results from Section 6.1 and 6.9 calculations do not accurately reflect what happens in operation. Additional operational energy modelling is therefore required to ensure that a suggested energy strategy works as intended ‘in use’.
The multiple design options to help meet Scotland’s net zero aspirations are complex. For example, a low energy building envelope would optimise the balance between functional brief and operational efficiency by balancing heat loss against the benefits of natural daylight, while minimising excessive solar gain.
Such a solution would form a passive element of the climate control and reduce the level of services required. Beyond form and fabric, the focus must be on the reduction of energy consumption through efficiency measures and low carbon energy generation.
An operational energy modelling exercise at the design stage can also be used to predict operational energy usage, aiming to avoid the energy efficiency performance gap found on most completed builds. Post-occupancy monitoring would also ensure that operational energy and CO2 emissions targets are not exceeded once the building is in use.
With emissions from buildings accounting for 20% of Scotland’s greenhouse gas emissions, decarbonisation of buildings must increase significantly to achieve these aims.
We should therefore build on, accelerate and scale up action to reduce building emissions.