Client: Church of England
In 2020, the Church of England announced an aim to achieve net zero carbon as an organisation by 2030 , 15 years earlier than previously planned. The background to the Synod decision is the global climate emergency, and the need for urgent action to avert its most devastating consequences.
The 2015 Paris Climate Agreement has set a target of limiting global average surface temperature rise to 1.5°C. The global scientific community is clear that this requires unprecedented action to cut global emissions of greenhouse gases by 45% by 2030, and to net zero by 2050. These global figures imply that those with greater resources should cut emissions harder and faster. Indeed, more ambitious targets have been declared by businesses, governments, and organisations worldwide. However, declaring a target is only the first step to achieving real, meaningful reductions.
Operational carbon emissions include direct emissions due to fuel combustion (Scope 1) and indirect emissions due to purchase of heat and electricity (Scope 2). This measure therefore reflects the operational energy use of the building. Net zero operational carbon is reached by achieving the net zero operational carbon balance between direct and indirect emissions, and displaced emissions due to on-site renewable energy generation, and emissions offset through certified schemes .
QODA’s approach to reducing the operational carbon footprint of a building follows the net zero carbon hierarchy shown below, focusing first on energy demand reduction. In the first instance, this can be through improvements to the building fabric or the building operation, for example the heating period or setpoint temperature.
The second step focuses on the implementation of an efficient, low carbon heating system, alongside efficient lighting and appliances. A low carbon heating system typically takes the form of electric heat pumps, which harness energy from the ambient environment; or district heating, which delivers heat from a central low carbon energy centre directly to consumers.
The third step in the hierarchy is to incorporate renewable energy generation and consumption on-site, for example through solar photovoltaic (PV) systems. This technology can complement electricity-based heating solutions.
Where residual carbon emissions still remain after all feasible measures from the first three steps have been implemented, a net zero carbon balance can be achieved through the purchase of carbon offsets commensurate with the carbon impact.
QODA was appointed by the Church of England to set out a roadmap to achieving net zero carbon emissions in operation by 2030 across its buildings. A portfolio of thirty-nine cathedrals and thirty See Houses were analysed as part of this project.
To evaluate what the transformation to net zero carbon would mean at each site, surveys were conducted to document the existing building fabric and services, and energy consumption data was used to evaluate the current operational carbon footprint. From the surveys and site context, various building fabric and services improvement opportunities were identified, including improvements in building airtightness, insulation and glazing; replacing fossil fuel heating systems with low carbon heat sources such as air or ground source heat pumps; and installing solar photovoltaics to generate renewable electricity on-site. This was accompanied by a clear overview of the technical considerations, benefits, challenges and risks that must be carefully navigated in each case, particularly given the historic value and sensitive nature of the buildings.
The operational energy and carbon reduction potential of these improvement opportunities relative to a ‘Do-Nothing’ baseline was calculated using an in-house assessment tool, allowing options to be ranked in terms of their effectiveness. Options were also compared in terms of their estimated carbon-saving potential per £ invested and impact on running costs. Analyses also considered cumulative operational carbon emissions over the next twenty years to understand the impact of timing and phasing of the improvements.
QODA’s analysis showed that implementing maximum practicable improvements to building fabric and services by 2030 could deliver carbon savings of up to 75% across the cathedral buildings, and up to 92% across the See Houses, without the use of carbon offsets. The study has equipped the Church of England with a valuable set of information to guide future decision-making as it takes its decarbonisation plans to the next stage.