Specification Uplifts Required to Achieve the New GLA Targets

From January 2023, GLA guidance will result in new applications needing to enhance their energy efficiency specifications. All existing London Plan CO₂ reduction targets will now apply over the Part L 2021 baseline, which in practice represents a tougher target than the previous Part L 2013 baseline.

The 10% Be Lean (i.e. energy efficiency) target when applied over Part L 2021 is likely to prove most challenging. In addition to a specification which is required to meet the minimum Part L 2021 fabric energy efficiency (FEE) standard, the following measures are likely to be required:

• Higher performance MVHR systems (MVHR units with higher ventilation rates may also be required for Part O compliance, which may limit the efficiencies that can be achieved);
• Low flow rates in showers (≤ 8 l/s).

In some cases, the FEE strategy may also require revisiting should the above enhancements be insufficient to meet the 10% reduction. However, as the 10% target is based on CO₂ emissions, changes to the FEE strategy are best only adopted once opportunities to maximise improvements in services have been exhausted.