At the beginning of October 2019, the Royal Institute of British Architects (RIBA) launched a climate change initiative to encourage the profession and wider construction industry to achieve net zero whole life carbon for all new and retrofitted buildings by 2030. This was alongside a campaign for Government to set new regulatory standards. The RIBA 2030 Climate Challenge asks all Chartered Practices to commit to four key reduction targets around the topics of:
- Operational energy;
- Embodied carbon;
- Potable water use; and
- Several core health and wellbeing targets.
RIBA proposes a radical change to building energy use, targeting less than 55 kWh per square metre of floor area per year (kWh/sqm/yr) for all operational energy uses in non-domestic buildings by 2030 (minimum DEC A or 75% reduction in operational energy as compared to CIBSE TM46 benchmarks). The standard is to be incrementally achieved over the next 10 years. The current benchmark from CIBSE, although a few years old now, for non-domestic buildings is 225 kWh/sqm/yr.
This is a more radical target than the UKGBC Consultation paper of energy performance targets for commercial offices. UKGBC believes that the most viable option would be targeting 72 kWh/sqm/yr as a ‘Paris-proof’ target i.e. a target that aligns with future national commitments for renewable energy generation.
For reference, the Dutch Green Building Council (DGBC) developed the ‘Paris Proof’ concept and reported that the targets should consider the use of the building. DGBC concluded that for a fully sustainable energy supply, an office building may only use 50 kWh/sqm/yr. Targets for other building uses from the DGBC include:
- Retail 80 kWh/sqm/yr
- Education 65 kWh/sqm/yr
- Care 90 kWh/sqm/yr
- Industrial 50 kWh/sqm/yr
The RIBA target does not account for the difference in building uses that the DGBC have set out. The achievement of a singular operational energy target for all archetypes will be problematic for buildings that have intensive unregulated energy demands.
Instead of a singular building energy target that captures all energy uses in a building, the industry could work towards defining a more universal regulated energy target that all buildings types should meet to cover their heating, cooling, ventilation and lighting demands. An activity-based target could then be developed for the numerous building use types. Such targets would allow designers to be more focused on what fabric and systems can achieve and make sure the base build is optimised and standardised.
RIBA have proposed universal embodied carbon intensity for buildings, targeting less than 500 kilograms of carbon dioxide per square metre of floor area per year (kgCO2/sqm/yr) using a whole life carbon assessment in non-domestic buildings by 2030. The standard is to be incrementally achieved over the next 10 years. RIBA urges designers to target net zero whole life carbon for new and retrofitted buildings by 2030.
Again taking a one target fits all methodology to embodied carbon will prove difficult for designers and Greengage are unsure whether these targets will get large scale industry buy in without some additional guidance around them.