Author: Oliver Wakefield-Smith, Founder Digital Signet. Reviewed against DfE Sustainability Strategy (Mar 2025) and Education Estates Strategy (Feb 2026). Verified 22 June 2026.
£18 to £32 per m2 for a full LED relamp including emergency lighting and contractor mark-up. Bundled DALI or KNX controls add £4 to £9 per m2.
£18 to £32 per m2 for a full LED relamp including emergency lighting and contractor mark-up. Bundled DALI or KNX controls add £4 to £9 per m2.
A 7,500 m2 secondary saving 8 kWh/m2/year on lighting at 26.11p/kWh saves around £15,700 per year, returning a payback inside the Salix 8-year average gateway for most sites.
Bundling pays where occupancy is variable (sports halls, drama spaces) or where daylight harvesting cuts perimeter zones. Standalone LED swap without controls remains the floor of acceptable PSDS scope.
LED-only projects below the Salix payback gateway commonly fall outside PSDS scope unless bundled with fabric or heating measures. CIF can fund standalone LED programmes within the condition envelope.